HomeMy WebLinkAboutbocc.ord.003.2008ORDINANCE OF THE BOARD OF COUNTY COMMISSIONERS OF
PITKIN COUNTY, COLORADO,
REPEALING PITKIN COUNTY CODE TITLE 6, CHAPTER 6.28, "INDIVIDUAL SEWAGE
DISPOSAL SYSTEMS" AND REENACTING PITKIN COUNTY CODE TITLE 6,
CHAPTER 6.28, "ONSITE WASTEWATER TREATMENT SYSTEMS"
ORDINANCE NO. GY 3 -2008
RECITALS
A. WHEREAS, the Board of County Commissioners serves as the local Board of Health for Pitkin
County and, as such, has the authority to adopt rules and regulations governing the design, construction,
installation, repair, modification, maintenance and use of onsite wastewater treatment systems; and
B. WHEREAS, the Board of County Commissioners desires to adopt new rules and regulations
governing the design, construction, installation, repair, modification, maintenance and use of onsite
wastewater treatment systems to preserve and protect the environment and to protect the public health,
safety and welfare.
NOW, THEREFORE, BE IT ORDAINED by the Board of County Commissioners of Pitkin County,
Colorado that:
1. Pitkin County Code Title 6, Chapter 6.28, "Individual Sewage Disposal Systems" is hereby
repealed in its entirety.
2. Pitkin County Code Title 6, Chapter 6.28, "Onsite Wastewater Treatment Systems," attached
hereto as Exhibit A, is hereby enacted.
INTRODUCED, FIRST READ, AND SET FOR PUBLIC HEARING ON JANUARY 9, 2008.
NOTICE OF PUBLIC HEARING AND THE FULL ORDINANCE PUBLISHED IN THE ASPEN
TIMES WEEKLY ON DECEMBER 9, 2007.
ADOPTED AFTER SECOND READING ON JANUARY 23, 2008.
PUBLISHED BY TITLE AND SHORT SUMMARY, AFTER ADOPTION, IN THE ASPEN TIMES
WEEKLY ON FEBRUARY 3, 2008.
THIS ORDINANCE SHALL BECOME EFFECTIVE 45 DAYS AFTER FINAL ADOPTION
ATTEST:
--~
i
By: ,
Jeanette Jones
Deputy Count Clerk
BOARD OF COUNTY COMMISSIONERS:
By: L~~'Gf ~~ , :.T
J ck Hatfield, C airman
i
Date: .~ ~ ~~
APPROVED AS TO FORM:
t._.. ._'--~
_..
John Ely, County-Attorney
ter:-- .
MANAGER APPROVAL:
~, ;
Hilary Flet ,County Manager
3
6.28 ONSITE WASTEWATER TREATMENT SYSTEMS
Table of Contents
Page Number
6.28.010 Title, Authority and Purpose
A. Title
B. Authority and Purpose
6.28.020 Administration
A. Activities Requiring a Permit; Withholding of Building
Permits and Certificates of Occupancy 1
B. Permit Types 1
1. OWTS Construction Permit 1
2. OWTS Use Permit 2
C. Permit and Inspection Fees 2
D. Permit Conditions
E. Expiration and Revocation of Permit 3
F. Onsite Location of Permit 3
G. Denial of Permit 3
H. Appeal 3
6.28.030 OWTS Permit Procedures 4
A. OWTS Construction Permit 4
1. Permit Application Process 4
2. Initial Site Inspection 4
3. Additional Tests or Documentation 4
4. Evaluation Criteria 4
5. Finallnspection 5
6. Emergency Repairs 6
B. OWTS Use Permit 6
6.28.040 Setbacks and Other Factors Affecting OWTS Siting 7
A. Minimum Horizontal Distances 7
B. Ground Conditions 8
1. Cut Slopes 8
2. Filled Ares and Compacted Areas 9
3. Groundwater and Bedrock; Surface Water 9
4. Floodway and Floodplain 9
5. Soil Cover 9
6. Waters of the State 9
7. Easements 9
6.28.050 Wastewater Flow and Characteristics 10
A. Average Daily Wastewater Flow and Design Flow 10
B. Residential Uses 10
C. Non-Residential Uses 10
6.28.060 Soil Tests 12
A. Testing Requirements 12
B. Soil Profile Hole or Boring 12
C. Percolation Test Holes and Testing Procedures 13
D. Soil Gradation Analysis 14
E. Depth to High Groundwater 14
F. Time of Year 14
March 8, 2008
G. Reports 14
6.28.070 Septic Tanks -Sizing, Design Criteria, and Installation 14
A. Septic Tank Size 14
B. Septic Tank Design 15
1. Configuration 15
2. Inlets and Outlets 15
3. Effluent Filters 15
4. Access 16
a. Access Openings 16
b. Access Opening Covers 16
c. Access Opening Riser Joints 16
C. Septic Tank Materials 16
a. Concrete 16
b. Fiberglass and Polyethylene/Plastic 16
c. Metal and Wood 16
d. Other Materials 17
D. Septic Tank Installation 17
a. General 17
b. Depth of Burial 17
c. Backfill 17
E. Connections 17
F. Operation and Maintenance 17
6.28.080 Absorption Systems -Sizing, Design Criteria, and Installation 17
A. Absorption Area 17
B. Absorption System Siting 19
C. Absorption Beds 19
D. Absorption Trench Systems 19
E. Gravelless Chamber Systems 19
F. Serial Systems 19
G. Alternating Absorption Systems 20
H. Dry Wells 20
I. Pipe and Gravel System Materials and Construction 20
J. Dosing and Pumps 21
K. Reduction Allowances 22
L. Distribution Pipes 23
M. Vents and Observation Pipes 23
N. Cleanouts 24
O. Distribution Valves or Distribution Boxes 24
P. Construction in Adverse Weather Conditions 24
6.28.090 Other Systems 24
A. Mound System 24
1. General Design Requirements 24
2. Absorption Area 25
3. Effluent Application Rate and Method 25
4. Absorption Area Aggregate; Chambers 25
5. Use of Liners 26
6. Soil Cover 26
B. Sand Filter 26
1. General Design Requirements 26
2. Absorption Area 26
3. Effluent Application Rate and Method 27
C. Constructed Wetland 27
March 8, 2008
D. Aerobic Wastewater Treatment System
E. Secondary Treatment and Advanced Secondary Treatment
F. Wastewater Pond
G. Evapotranspiration System
H. Evapotranspiration/Absorption System
1. General Criteria
2. Water Balance Method
3. Subsurface Drip System
906.28.100 New Technology System
A. Certification
B. Design and Field Testing
C. Back-Up System
6.28.110 Revegetation of All OWTS Sites
A. Revegetation Requirements
B. Maintenance of Vegetation
6.28.120 Construction Observation by a PE
28
28
28
29
29
29
29
30
31
31
31
31
31
31
32
32
6.28.130 Operation and Maintenance 32
A. Responsibility 32
B. Service Label 32
C. Operation and Maintenance Manual 32
D. Maintenance, Cleaning, and Inspection 32
E. Monitoring and Sampling 33
F. Disposal of Waste Materials 33
G. Discharge Quality and Permits 33
H. Termination of Use 34
6.28.140 Miscellaneous Systems; General Prohibitions 34
A. Grey Water Systems 34
B. Vaults 34
C. Vault Privies 34
D. Incineration Toilets 35
E. Chemical Toilets 35
F. Composting Toilets 35
G. Cesspools 36
H. Hot Tubs and Therapeutic Bathing Facilities 36
I. Water Softeners 36
J. Floor Drains 36
K. Business, Commercial, Industrial, Institutional, or Multi-Family
Dwelling Waste Systems 36
6.28.150 Licensing 36
A. General 36
1. Systems Contractors 36
2. System Cleaners 37
3. System Inspectors 37
B. Licensing Procedures for Systems Contractors, Cleaners,
and Inspectors 37
C. Standards of Performance 37
1. General 37
2. Additional Standards of Performance for Licensed
Systems Contractors 38
3. Additional Standards of Performance for Licensed
March 8, 2008
Systems Cleaners 38
4. Additional Standards of Performance for Licensed
Systems Inspectors 38
D. Revocation of Licenses 38
6.28.160 Prohibitions on Permits 39
6.28.170 Enforcement 39
A. Primary Enforcement Responsibility 39
B. Access to Site 39
C. Complaints Regarding Violations 39
D. Notice of Violation; No Other Approvals or Permits to Be Issued 39
E. Cease and Desist Order 40
F. Penalties 40
G. Liens and Costs of Collection 41
6.28.180 OWTS Zones 42
A. Designations 42
B. Performance 42
6.28.190 Definitions and Acronyms 42
A. Scope 42
B. General Definitions and Acronyms 43
Tables
Table 6.28-1
Page Number
Minimum Horizontal Distance (in Feet) Between OWTS
Components and Pertinent Physical Features 8
Table 6.28-2
Amounts of Wastewater for Various Types of Uses 10
Table 6.28-3
Long-Term Acceptance Rate (LTAR) 18
Table 6.28-4
Summary of Allowable Reductions 23
Table 6.28-5
Gradation of Mound System Absorption Area Aggregate 25
Table 6.28-6
Soil Absorption Rates Using the Water Balance Method 30
Table 6.28-7
Gradation Requirements for Sand Used in ETA Absorption Beds 30
Table 6.28-8 33
Maintenance and Cleaning Frequency
March 8, 2008
6.28 ONSITE WASTEWATER TREATMENT SYSTEMS
6.28.010 Title, Authority and Purpose
A. Title
This chapter, as amended from time to time, shall be known as the Pitkin County Onsite Wastewater
Treatment System Regulation.
B. Authority and Purpose
1. This Regulation is adopted pursuant to §25-10-101 et.seq. C.R.S.
2. The purpose of this Regulation is to establish requirements for the design, construction,
installation, repair, modification, maintenance, and use of all OWTSs in Pitkin County with average daily
wastewater flows less than 2,000 GPD and rules for the administration and enforcement of such
requirements. Such requirements and rules are necessary to preserve and protect the environment and
to protect the public health, safety and welfare.
6.28.020 Administration
A. Activities Requiring a Permit; Withholding of Building Permits and Certificates of Occupancy
1. No person shall construct, install, alter, or repair any OWTS, obtain a building permit for a
property served by an OWTS, or sell a property served by an OWTS, without first having obtained a
permit for such activity, as required by this Regulation. The type of activity determines whether an OWTS
construction permit or use permit is required, as described in Section 6.28.020(8).
2. Although the CWQCD is responsible for permitting large-capacity OWTSs, a permit (which shall
be contingent on CWQCD approval) shall also be obtained from the Department to ensure that alarge-
capacity OWTS also complies with County requirements.
3. Pitkin County shall not issue to any person a building permit to construct, remodel, or repair a
building until a permit has been issued by the Department when such building construction, remodel, or
repair will result in: a) a use requiring treatment and dispersal of wastewater, or b) a use increasing the
requirements for treatment and dispersal of wastewater. Exception shall be made for: i) a building served
by a wastewater treatment works, ii) a building on a property covered by a valid construction permit or use
permit, as described below, or iii) a building which the Department has confirmed, in writing, does not
require a permit. Pitkin County shall not issue a Certificate of Occupancy for a building served by an
OWTS until final inspection and approval of the OWTS has been received from the Department.
B. Permit Types
1. OWTS Construction Permit
a. An OWTS construction permit is required for all new construction, as well as the installation,
alteration (including expansion), or replacement of an OWTS. An OWTS construction permit is also
required for repair of an OWTS, other than minor repairs to system components (e.g., replacement of a
broken or crushed pipe). Requirements for repair shall be determined by the Department.
b. Expanded use of an existing OWTS includes the addition of bedrooms or rooms that may be
used as bedrooms in the future, or the conversion of rooms into bedrooms, or any other modification that
may affect water use. The Department will review plans for alteration or remodeling of buildings to
determine if it is necessary to expand the OWTS. In no circumstance may an OWTS existing prior to
March 8, 2008 Page 1
adoption of this Regulation be expanded in violation of this Regulation, or in violation of §25-10-101
et. seq. C.R.S.
c. In conjunction with a permit issued for repairs, the Department may authorize use of a
malfunctioning OWTS, or an interim vault or vault privy, on an emergency basis (not to exceed the period
stated in the permit), provided that the Department determines that there is not an immediate threat to
public health or the environment.
2. OWTS Use Permit
a. Effective on and after March 8, 2009, prior to the sale of a property served by one or more
OWTSs (including any OWTS in existence prior to adoption of this Regulation), the owner(s) of the
property shall obtain an OWTS use permit for each system on the property. This requirement shall be
waived if: a) each OWTS on the property received final approval for an OWTS construction permit from
the Department within the five year period preceding the date of closing on the real estate transaction, or
b) following inspection, a construction permit has been issued by the Department for each noncompliant
OWTS on the property and the buyer has agreed, in a writing acceptable to the Department, to assume
the applicant's obligations under the permit and to complete the necessary repair/construction within the
timeframe dictated by the permit.
b. Effective on and after March 8, 2009, an OWTS use permit shall also be required prior to
issuance of a building permit for a property already served by one or more OWTSs. This requirement
shall be waived if each OWTS on the property has received final approval of an OWTS construction
permit within the five year period preceding the date of issuance of the building permit.
c. The Department, in its discretion, may waive the requirement for an OWTS use permit where
warranted by a particular fact situation (e.g., a buyer agrees to demolish an existing dwelling and
abandon the existing OWTS within a defined time period).
C. Permit and Inspection Fees
Fees for permits, inspections and other services provided by the Department shall be established
from time to time by the Department, in accordance with state statute. All fees are non-refundable.
D. Permit Conditions
1. The Department may condition any permit with mandatory site or system specific requirements
and prohibitions. In all cases, the Department shall have the right to require that a permitted system be
abandoned and served by a wastewater treatment works, if available in the future.
2. The Department may require financial security, in the form of a Performance Deposit, to ensure
adequate revegetation of an OWTS site, in accordance with Section 6.28.110, following completion of
installation, alteration, or repair of an OWTS. The Performance Deposit amount shall be determined by
the Department and may be held for two complete growing seasons following completion of the
installation, alteration, or repair, or until the vegetation has been successfully established to the
reasonable satisfaction of the Department.
3. The issuance of a permit shall not constitute or create a presumption that the Department or its
employees shall or may be liable for the failure of any system, nor act as a certification that the system,
the equipment used in the system, or any component thereof, is or will be in compliance with applicable
state statutes, regulations and policy directives, the provisions of this Regulation, or any terms and
conditions of a permit.
March 8, 2008 Page 2
E. Expiration and Revocation of Permit
1. Permits for the construction, installation, or alteration of an OWTS shall expire at the end of one
year from the date of issuance, if construction has not commenced. Expired OWTS construction permits
may be reactivated at the discretion of the Department for a period of one year, upon payment of the
applicable fees. Any modifications to the original permit application will require submission of an
application for a new permit and payment of applicable fees.
2. Where a construction permit is issued for repairs, the permit shall provide a maximum 30-day
period within which repairs shall be made, at which time the OWTS shall be inspected by the Department.
The Department may extend the permit for an additional 30-day period, for good cause shown, in the
event that repairs cannot be completed in the required time period through no fault of the applicant.
3. All construction permits issued prior to the effective date of this Regulation will expire according to
their terms. A permit which has not previously been extended (for twelve months or less), will be subject
to the reactivation provisions stated above. All other previously-issued permits will require new permit
applications under this Regulation.
4. OWTS use permits shall remain valid until the earlier of: a) the date of closing on the real estate
transaction for the property served by the OWTS, b) the date of issuance of a building permit for the
property served by the OWTS, or c) twelve months from the date of issuance, whichever occurs first.
5. Any permit found to have been issued on the basis of inaccurate, false, or misleading information
provided by applicant or its representative(s) may be revoked by the Department with notice to applicant.
F. Onsite Location of Permit
OWTS construction permits and all corresponding design information shall be kept on the job site
during the construction, installation, alteration, or repair of any OWTS until final inspection approval has
been given by the Department.
G. Denial of Permit
The Department shall deny a permit application for the construction, installation, alteration, use, or
repair of an OWTS if: 1) the application fails to comply with any requirement of this Regulation, 2) a
wastewater treatment works is available and willing to provide service to the site, 3) the granting of such
an application would be in violation of any other applicable statute, rule, or regulation, or 4) the granting of
such an application would create or continue a nuisance detrimental to public health and/or the
environment. A determination to deny a permit application shall be in writing and shall include the specific
reasons for the denial. The written denial shall be mailed, by certified mail, to the applicant at the address
on the application. Denial shall be complete upon mailing and does not require actual receipt by the
applicant.
H. Appeal
1. The applicant may appeal a denial of a permit application to the Board of Health by filing a notice
of appeal and a brief written statement of the grounds for the appeal with the Department no later than 60
calendar days after the written denial is postmarked. A nonrefundable fee, as established by the
Department, shall be paid by each applicant for an appeal. Within 15 business days of receipt of a timely
and properly documented notice of appeal, the Department will schedule an appeal meeting (which shall
be a public meeting) before the Board of Health. To the degree possible, appeals will be scheduled for
the next regularly scheduled meeting of the Board of Health with an available time slot.
2. At the meeting on the appeal, the Board of Health shall review the record of the Department's
decision and shall provide the applicant an opportunity to discuss the grounds for the appeal and the
March 8, 2008 Page 3
basis for the alleged error in the Department's decision. The Board of Health may also hear from any third
party it deems appropriate. The Board of Health shall only reverse, modify, or remand a decision on
appeal if it finds that there has been a clear and demonstrable error, abuse of discretion, or denial of
procedural due process in the application of the facts in the record to the requirements of this Regulation.
6.28.030 OWTS Permit Procedures
The Department web page on the Pitkin County website should be referenced for current permit
applications and checklists, fees, policies and guidance documents. The Department will not begin
review of a permit application until a complete and fully-executed application has been received, with all
required documentation and fees, as specified on the checklist. It is the obligation of the applicant to
ensure the sufficiency of the application package and fees prior to submittal.
A. OWTS Construction Permit
1. Permit Application Process
An OWTS construction permit application form and checklist shall be obtained from the Department
for the activities specified in Section 6.28.020(8)(1). The construction permitting process includes
submission of a complete and fully executed permit application and all necessary supporting
documentation and fees (as specified on the checklist), an initial site inspection, and a final site
inspection.
2. Initial Site Inspection
After the Department has reviewed the OWTS construction permit application package and
determined it is complete, the Department shall schedule and perform an inspection. The applicant, or the
applicant's authorized representative, shall clearly stake and label the site prior to inspection, including all
components of the OWTS, proposed buildings, source of domestic water, and other items that may be
requested by the Department. At a minimum, the site inspection shall include a preliminary review
regarding the suitability of the site for the proposed OWTS components considering the surrounding land
use, the proposed use of the site, soil suitability, depths to bedrock and high groundwater, ground slope,
and the ability to meet the setback requirements of the property relative to water courses, wells, wetlands
and other pertinent physical and environmental features specified in Section 6.28.040 of this Regulation.
Initial site inspections will be limited to May 1 through October 31, unless weather and site conditions
provide Department staff with safe and easy access for an accurate assessment of the site. The
Department may waive the requirement for a site inspection in instances where staff has sufficient
familiarity with a site to independently evaluate the application.
3. Additional Tests or Documentation
If the Department determines that there is insufficient information for evaluation of an application, it
shall require additional tests or documentation. When specific evidence suggests that undesirable
surface, subsurface, or other conditions exist, the Department may require that the applicant submit
additional hydrologic, geologic, engineering, or other information, including, but not limited to data,
opinions or certifications provided by a PE or qualified geologist. All additional testing and evaluations
shall be at the expense of the applicant.
4. Evaluation Criteria
All OWTS construction permit applications will be evaluated based on the criteria specified in this
Regulation. In order for a permit to be issued, the following criteria must be met:
a. An adequate water supply must be demonstrated for private water systems in accordance
with Colorado water law, this Regulation and the requirements of the Pitkin County Land Use Code. An
March 8, 2008 Page 4
adequate water supply provided by public water systems requires documentation of approval by the
CWQCD and must satisfy the requirements of the Primary Drinking Water Regulations. Onsite water
supply wells must be drilled prior to approval of an OWTS construction permit application. If a water
supply will not be obtained on site, then additional written documentation demonstrating legal access to
the alternative water supply (e.g., recorded easements) must be provided.
b. All land use approvals and other relevant permits must be obtained (and recorded, as
necessary) prior to issuance of an OWTS construction permit. These may include, but are not limited to, a
Pitkin County Community Development-approved site plan delineating the area(s) approved for
development. Systems must be sited within designated development envelopes, where required.
c. All OWTS designs must adhere to the technical criteria of this Regulation with regard to
sizing, location, materials, piping, backfill, and other factors.
d. Setbacks from reservoirs, lakes, streams, ditches, wells, wetlands, floodplains, riparian
zones, and other features specified in Section 6.28.040 of this Regulation must be met.
e. OWTSs shall be designed, constructed, installed, repaired, replaced and altered in a manner
that protects water resources, particularly in environmentally sensitive or vulnerable areas. Where water
bodies are subject to TMDLs, an OWTS shall only be permitted in accordance with load allocations
assigned under such TMDLs.
f. OWTSs located in easements shall meet all requirements of Section 6.28.040(6)(7) of this
Regulation. Activity and development restrictions above the OWTS must be clearly documented and
recorded (as necessary).
5. Finallnspection
a. The licensed systems contractor or property owner (if an authorized self-installation has
occurred) shall request a final inspection of the OWTS from the Department and the PE who designed the
system prior to backfilling of any excavation related to the system or its components, unless the
Department and the PE have given permission to begin partial backfilling under specific circumstances. If
a dosing device is installed, one complete cycle of that device must be observed by the PE designing the
OWTS and/or the Department. In the event the Department is called for a final inspection of an OWTS
and the OWTS is not ready for a final inspection on the date specified, the applicant shall be assessed an
additional fee for staff time spent traveling to and from the site, using the Department's hourly rate. This
fee must be paid prior to receipt of final system approval.
b. Following inspection, final grading must be completed and an "as-built" drawing shall be
submitted to the Department, including, at a minimum, a site plan showing actual construction details and
the actual locations of OWTS components, including GPS coordinates. For OWTSs constructed under
supervision of a PE, the PE shall also certify in writing to the Department that construction and installation
of the system have been completed in accordance with the terms of the engineered design that was
submitted to and approved by the Department. "As-built" drawings must be received by the Department
within 30 days of final inspection by the Department, unless a longer period of time has been agreed to by
the Department, in writing. The Department shall assess an additional permit fee (which must be paid
prior to receipt of final system approval) if an "as-built" drawing is not timely received.
c. If the Department determines that the OWTS has been constructed, installed, altered,
repaired, replaced, and/or relocated in accordance with this Regulation and the permit requirements, the
Department shall issue final approval for the completed system. If the review and/or inspection discloses
any significant departure from the location or design of the OWTS as stated in the application and permit,
or if any aspect of the OWTS fails to comply with this Regulation, final approval shall be withheld. Written
notice of the deficiency(ies) shall be provided to the applicant. Final approval shall be granted only when
March 8, 2008 Page 5
reinspection has occurred and the system has been determined to be in compliance with the
requirements stated above.
d. Any changes to the approved installation that result in conditions that would have prohibited
the system from meeting the requirements of this Regulation at the time of final approval (e.g., covering
septic tank access ports in excess of allowable depth, changes to the depth of the absorption area,
removal of inspection ports or vents, inadequate or improper revegetation) will subject the property
owner(s) to mandatory upgrades and repairs at such time as a system inspection, complaint investigation,
or other site visit reveals such violation of this Regulation.
6. Emergency Repairs
a. An application for an OWTS construction permit shall be submitted to the Department by the
property owner(s) (or an occupant, if the owner(s) cannot be reached) within two business days after a
malfunctioning system or component becomes evident, or is brought to the attention of the
owner(s)/occupant(s) following a system inspection, or after a notice is provided by the Department that
the OWTS is not functioning in compliance with this Regulation or otherwise constitutes a nuisance or
hazard to public health and/or the environment.
b. In the case of a malfunctioning system, the applicant may request authorization for
emergency use of the existing system, or the emergency use of a vault or vault privy, during the repair
period.
c. As a condition of issuing a permit for emergency repairs, the Department may require a firm
schedule for the repairs and proof of the ability to timely perform the requisite repairs, including but not
limited to a contract for such repairs. The Department may also require insurance, bonding, or other
provisions be made to ensure mitigation of any damage that may be caused by the emergency use of a
malfunctioning or alternative system.
B. OWTS Use Permit
1. Effective on and after March 8, 2009, an OWTS use permit is required for property transactions
resulting in a change in ownership of a property served by an OWTS or requiring a building permit, unless
exempted under Section 6.28.020(8)(2). The use permitting process includes submission of a complete
and fully executed permit application and fees, together with the following additional information and
supporting documentation:
a. A site plan showing the existing topography, location of each existing OWTS and each
OWTS's relation to buildings, property lines, ditches, water courses, source of domestic water, other
OWTSs, and such other information, as may be required pursuant to Section 6.28.040. GPS coordinates
documenting existing OWTSs' locations shall also be provided.
b. A description and layout of each OWTS on the property.
c. A written inspection report by a licensed systems inspector or the Department documenting
an inspection conducted within the one year period preceding the date of issuance of the use permit
providing an assessment of the condition of each existing OWTS and each OWTS's ability to serve the
property without adverse impact to public health and the environment, and specifying any repairs,
enlargement or other alteration necessary to bring an OWTS into compliance with the requirements of
this Regulation.
d. In instances where a use permit is being sought in connection with an application for a building
permit, the applicant must also submit building plans in order to verify that the size of the existing
OWTS(s) will accommodate the new construction and a recorded Pitkin County Community
Development-approved site plan delineating the area(s) approved for development to verify that the new
March 8, 2008 Page 6
construction will not result in site modifications that could adversely affect the functioning of the existing
OWTS(s) (e.g., soil compaction, modifications to drainage patterns). In instances where a use permit is
being sought in connection with a property transaction, current floor plans for the building(s) served by the
existing OWTS(s) shall be submitted.
2. If no repairs, enlargement, or other alterations are required, then an OWTS use permit shall be
issued. If construction or repairs are required to bring an OWTS into compliance with this Regulation,
then a construction permit application shall be submitted in accordance with Section 6.28.030(A).
6.28.040 Setbacks and Other Factors Affecting OWTS Siting
A. Minimum Horizontal Distances
1. Setbacks from specific physical features are established in order to minimize adverse impacts to
public health and the environment. These features and minimum setbacks are summarized in Table 6.28-
1. The Department may require greater distances where soils, geology, proximity to cut banks, or other
conditions warrant. The applicant may also be subject to more stringent setback requirements under the
Pitkin County Land Use Code. For repair or upgrading of existing systems where the size of the parcel
prevents meeting the setbacks in Table 6.28-1, the repaired or upgraded system may not have setbacks
smaller than those for the existing system; neither shall the existing system be enlarged within the
setback (e.g., increasing the size of the absorption area to accommodate additional bedrooms).
2. No OWTS component shall be located within 100 feet of a geothermal well unless: a) a variance
has been obtained from the State Engineer in accordance with the "Rules and Regulations for Permitting
the Development and Appropriation of Geothermal Resources Through the Use of Wells" (2 CCR 402-
10), and b) the State Engineer's variance has also been approved by the Department. To apply for
Departmental approval of a variance, the applicant shall submit a copy of the State Engineer's variance
approval and the application submitted to secure that variance with its permit application. In reviewing a
request for a variance the Department will consider: i) actual site conditions (including the availability of
alternative locations for the geothermal well), ii) the construction details, iii) any special precautions that
will be taken to protect the geothermal well from contamination, and iv) any special precautions that will
be taken to protect public health, safety and the environment.
3. Wells, springs, other bodies of water, riparian areas, and wetlands within 200 feet of an OWTS
absorption bed or trench shall be identified on the site plan submitted to the Department in connection
with a permit application.
March 8, 2008 Page 7
Table 6.28-1
Minimum Horizontal Distances (in Feet) Between OWTS Components and Pertinent Physical Features
C
O ~,
d
~ C -a
N N
L i p
U
~
~ L c
~~ ~ c
L~ ~~
~ J y N O~ Z
~ ~ ~
N
~
N : ~
N ~ ~ ~ O ~ --~ (0 U ~ J c'tj -~ Q
~ C
J _
t6 N
~_
> .
p~ U
C T
O m
m~
C -d C
J N O
L~ N 0~
O~ O
~
~
(0
C
c6
~ C O_ ~ ~ ~ D_ m ~ O N ~ > ~
-
~
C
'C Y
C .
L ~
~ (n ~ U
p O ~ fn L
N N ~ ~ ~ ~
~' ~. ~ '~ d _
~
(A o O
a. i- O
Absorption Trench,
Absorption Bed, Sand Filter
(see exceptions below), 100~Z~ 25 25 20 10 50~2~ 25~z~ 50~Z~ 15~2~
Subsurface Dispersal
S stem, or D Well
a. Lined Sand Filter 60 10 25 15 10 25 10 25 15
b. Unlined Sand Filter in
Soil with a Percolation 100~2~ 25 25 15 10 25 15 25 15
Rate < 60 MPI
Lined Wastewater Pond 60 10 25 15 10 25 10 25 15
Unlined or Partially Lined ~2~
Wastewater Pond 100 25 25 15 10 25 15 25 15
Dispersal System Using 100~Z~ 10 50 125 10 25~2~ 10~Z~ 25 15
Aerosol Methods
Vault Priv 50 10 25 15 10 25 10 25 15
Septic Tanks, Package
Plants, Dosing or Pumping 50~'~ 10 25 5 10 50 10 50 15
Chamber, Vaults
Building Sewer or Effluent 50~'~ 10 25~'~ 0 10~'~ 50~'~ 10~'~ 50~'~ 15~'~
Pi es
~'~ Crossings or encroachments may be permitted at the points identified by this footnote, provided that drinking water or
wastewater pipe is encased for at least 10 feet on each side of the crossing. Pipe of Schedule 40 rating or better must be used that
has a sufficient diameter to easily slide over and completely encase the pipeline. Ridged end caps of at least Schedule 40 rating
must be glued or secured in a watertight fashion to the ends of the encasement pipe. There must be a hole of sufficient size to
accommodate the pipe in the lowermost section of the ridged cap so that the conveyance pipe rests on the bottom of the
encasement pipe. The area in which the pipe passes through the end caps must be sealed with an approved underground sealant
compatible with the pipe used.
c2~ Add 8 feet additional distance for each 100 GPD of design flow over 1,000 GPD, unless it can be demonstrated by a PE or
qualified geologist that a mechanical or natural barrier will prevent contamination. If a PE or qualified geologist chooses to exercise
this option, he/she shall submit to the Department a detailed written explanation (including all supporting calculations) that clearly
and convincingly demonstrates why the additional 8-foot setback distance for each 100 GPD of wastewater is not necessary.
B. Ground Conditions
1. Cut Slopes
If the ground surface has been cut into (e.g., a road cut or cut bank) and the OWTS disperses effluent
into the surrounding soil, the minimum distance between the OWTS's outer edge and the cut slope shall
be four times the height of the cut measured from the bottom of the cut to the bottom of the OWTS. This
requirement can be waived if a PE or qualified geologist is able to clearly and convincingly demonstrate to
the Department, in writing, that a mechanical or natural barrier will prevent lateral surfacing of effluent.
March 8, 2008 Page 8
Minimum Distance to
Cut Bank
2. Filled Areas and Compacted Areas
An absorption system shall not be installed in a filled area unless it is designed by a PE. OWTSs are
prohibited in compacted areas, such as parking lots, driveways and construction staging areas.
3. Groundwater and Bedrock; Surface Water
There shall be a minimum of 4 feet of suitable soil between the bottom of an absorption system and
maximum high groundwater or bedrock. Surface water shall be diverted away from any absorption system
on the same or neighboring parcel. Where feasible, an absorption system site shall be located so surface
water drainage from the site is directed away from wells or reservoirs.
4. Floodway and Floodplain
New or expanded systems shall not be installed in a floodway. Installation of new or expanded
systems in a floodplain shall also be prohibited if another suitable site exists on a property. When a
system is installed, expanded, or repaired in a floodplain, the new, expanded, or repaired system shall
meet or exceed the requirements of the National Flood Insurance Program and shall be designed to
minimize or eliminate infiltration of floodwaters into the system and discharges of the system into
floodwaters.
5. Soil Cover
There shall be at least 1 foot of soil cover above an absorption system.
6. Waters of the State
Any system that will disperse effluent by a direct discharge to waters of the State must be designed
by a PE and a site application and design must be submitted to the CWQCD in accordance with 5 CCR
1002-61, "Regulation #61 Colorado Discharge Permit System Regulations." The Department may
approve the concept of the OWTS, but the CWQCD shall issue the discharge permit.
7. Easements
An absorption system may be installed in an easement, provided that there is a legally binding and
properly recorded agreement among all affected parties clearly specifying the permanent nature of the
installation and limiting use of the easement to the absorption system only. Development (e.g., parking,
driveways, storage, and animal confinement areas) must be clearly prohibited in the easement.
March 8, 2008 Page 9
6.28.050 Wastewater Flow and Characteristics
A. Average Daily Wastewater Flow and Design Flow
1. The average daily wastewater flow loading for various types of building and facility uses are
provided in Table 6.28-2. The Department shall refer systems treating an average daily wastewater flow
of 2,000 GPD or greater to the CWQCD.
2. Design flow is 150 percent of the average daily wastewater flow and is the basis for design of all
OWTSs. In no event may an OWTS be designed for a smaller capacity than the anticipated design flow or
treatment requirements of the wastewater in the system.
B. Residential Uses
As indicated in Table 6.28-2, a minimum of two persons per bedroom must be used to calculate the
average daily wastewater flow for dwellings, including mobile homes. A room that is likely to be used as a
bedroom during the life of the building is considered a bedroom for purposes of OWTS sizing. Average
daily wastewater flows for dwellings are based on the number of bedrooms, and potential bedrooms,
multiplied by 75 GPD per person for buildings with a living area up to 6,000 square feet and 100 GPD per
person for dwellings having living areas in excess of 6,000 square feet. The average daily wastewater
flow for a caretaker dwelling unit shall also be based on the number of bedrooms and potential bedrooms,
as described above. Average daily wastewater flow may be based on number and type of fixtures, as
described in Table 6.28-2, multiplied by the approximate number of people that will use the fixtures per
day, with Department approval.
C. Non-Residential Uses
Table 6.28-2 summarizes the average daily wastewater flow per person per day for various types of
commercial and other establishments. These averages shall be used as the basis for OWTS design flow
calculations.
Table 6.28-2
Amounts of Wastewater for Various Types of Uses
GPD Per Person
Type of Establishment (Average, Unless
Otherwise Stated
Residential Unless otherwise stated, 2 ersons er bedroom
Sin le-famil dwellin s <_6,000 s . ft" 75
Single-family dwellings of >6,000 sq. ft.* 100
Fixtures
Bath/shower 14.7
Toilet 24.8
Hand sink 8.4
Washing machine 19.5
Kitchen sink 4.4
Garbage disposal 1.4
Dishwasher 1.8
Boardin and roomin houses 50
Mobile home 75
Mobile homes ace er s ace 300
Hotels and motels - er room without rivate baths 50
Hotels and motels - er room with rivate baths 75
Multi le-famil dwellin s or a artments 75
March 8, 2008 Page 10
Commercial
Air orts
er assen er 5
er em to ee 10
Barber and beaut sho s er chair 100
Bowlin alle s er lane -not includin food or bar 5
Bus service areas (not includin food 5
Countr clubs
er member 30
er em to ee 20
Dentist offices er non-wet chair 50
Doctors offices er doctor 250
Fair rounds er erson attendin 5
Factories and lants exclusive of industrial wastes
er em to ee er 8-hour shift - no showers 20
er em to ee er 8-hour shift -showers rovided 35
Food service establishments er seat
Restaurant o en 1 or 2 meals 50
24-hour restaurant 75
Restaurant with a er service onl 25
Additional for bars and cocktail loun es 30
Drive-in restaurant er car s ace 50
Kennels er do 30
Laundries, self-service er commercial washer ** 400
Office buildin s er em to ee er 8-hour shift 15
Stores and shopping centers (per square foot of retail
s ace 0.1
Service stations er toilet fixture 250
Stadiums, race tracks, ball arks er seat 5
Theaters movie, indoor, or auditorium er seat 5
Work or construction camps (semi-permanent -with flush
toilets 50
Work or construction camps (semi-permanent -without
flush toilets 35
Institutional does not include kitchen wastewater flows
Churches not includin food 5
Hos itals er beds ace 250
Nursin homes er beds ace 100
Schools, boardin er student 100
Schools, da
without cafeteria, m or showers 15
with cafeterias, no m or showers 20
with cafeterias, m and showers 25
(additional for school workers 15
March 8, 2008 Page 11
~ Recreational and Seasonal ~
Cam s, da no meal served er erson 15
Luxu resort 125
Resort ni ht and da 50
Cam round seasonal occu anc - er unit *" 50
Public ark durin hours when ark is o en
-Flush toilet er fixture er hour 36
-Urinal er fixture er hour 10
-Shower er fixture er hour 100
-Faucet er fixture er hour 15
Swimmin ools and bathhouses 10
Travel trailer arks
with individual water and wastewater hooku - er unit '`* 50
(without individual water and wastewater hookup -per
unit ** 50
Other
Barn (includes toilet, hand sink, mop sink, and washing
machine 45
'` Square footage based on the total living area.
*" Facilities providing commercial washers shall calculate average daily wastewater
flows on a per washer basis, as described in "Commercial Laundries" in this table.
6.28.060 Soil Tests
A. Testing Requirements
1. Unless otherwise approved by the Department, soil testing shall be conducted on all sites by a
qualified geologist, PE, or a qualified field technician under the supervision of a qualified geologist or PE,
regardless of the type of OWTS planned to serve the parcel. Soil testing may be required to demonstrate
that another type of system, other than an absorption system, is needed (as addressed in Sections
6.28.090 through 6.28.100 of this Regulation).
2. The locations of all sampling for soil tests shall be accurately shown on the site plan submitted
with the permit application and drawn to scale, or with the horizontal dimensions between the
holes/borings and a horizontal reference point and/or existing site features clearly shown.
3. For absorption area sizing using the formula specified in Section 6.28.080(A)(2) and the LTAR
from Table 6.28-3, at least three percolation tests or a soil gradation test is required. For absorption area
sizing using the formula specified in Section 6.28.080(A)(3), at least three percolation tests are required.
4. The Department may request additional soil percolation tests and/or soil profile holes or borings to
enable an accurate evaluation of a site.
B. Soil Profile Hole or Boring
1. A minimum of one soil profile hole or boring shall be excavated or drilled to provide evaluation of
the soil profile in the absorption system area, located in accordance with Section 6.28.080(8). In an area
of homogenous soils, the soil profile hole or boring shall be located adjacent to the lowest anticipated
portion of the absorption area to minimize soil disturbance. The soil profile hole or boring shall be at least
March 8, 2008 Page 12
8 feet in depth, or of sufficient depth to evaluate the soils 4 feet below the bottom of the proposed
absorption area, whichever is greater.
2. Soil profile holes shall be excavated in a manner that does not pose a safety hazard, in
accordance with Occupational Safety and Health Administration (OSHA) requirements.
3. The soil profile shall be documented by a qualified geologist, PE, or qualified field technician
under the supervision of a qualified geologist or PE. A soil log shall be completed by classifying the soil
profile following the USDA NRCS field evaluation procedure, as outlined in the Field Book for Describing
and Sampling Soils (utilizing the soil texture triangle), or ASTM Standard D2487-00, "Standard
Classification for Soils for Engineering Purposes." Soil horizons shall be differentiated on the basis of
color, texture, structure, soil mottles, or bedrock. The thickness in inches of each soil horizon and the
depth of each soil horizon from the ground surface shall be measured and documented. The constraining
soil strata within 4 feet below the bottom of the absorption area shall be identified and used for absorption
area sizing. The soil gradation sample shall be taken from this stratum for testing.
4. Observed groundwater shall be reported at the level to which groundwater rises in the soil profile
hole or boring and at the highest level of sidewall seepage into the excavation. Soil located above the
water level in the excavation shall be checked for the presence of soil mottles. Continued monitoring of
groundwater levels may be required by the Department. A 2-inch to 4-inch-diameter perforated pipe shall
be installed in the soil profile hole or boring at the time of backfilling to allow for subsequent water level
monitoring.
C. Percolation Test Holes and Testing Procedures
1. Percolation test holes shall be spaced uniformly over the proposed absorption area, with at least
one percolation test hole in every soil texture type in the proposed absorption area and in every 1,200
square feet of the proposed absorption area.
2. Pits for percolation tests must be approximately 3 feet in width and to the depth of the proposed
absorption area. A backhoe may be used to excavate the pit. The pit shall have adequate width and
length to allow a person to enter the pit with a shovel, post-hole digger, and pry bar or pick axe without
knocking loose soil into the hand-dug percolation test hole.
3. Percolation test holes shall be hand-dug, hand-bored, or power augered within the excavated pit
to the depth of the proposed absorption area. When power augers are used, the bottom and sides of the
hole shall be scratched with asharp-pointed instrument to expose the natural soil. All loose material shall
be removed from the hole. The test holes shall have vertical sides and a horizontal diameter of 6 inches.
Where prohibitive geologic conditions exist, the diameter may vary from 4 to 12 inches. The percolation
test hole must be at least 14 inches deep, with the bottom of the hole terminating at the depth of the
proposed absorption area, provided that if an auger is being used in homogeneous, fine-grained,
cohesive soil, the hole shall be drilled to a minimum depth of 3 to 4 feet, or to the bottom of the proposed
absorption area, whichever is deeper. Auger holes drilled deeper than 3 feet or in sandy gravel shall be
cased with a slotted PVC pipe. The purpose of the percolation tests shall be to define the hydraulic
character of any constraining layers within those soils comprising the 4 feet beneath the bottom of the
absorption area.
4. To conduct the percolation test, the test hole shall be filled with water to a minimum depth of 14
inches for at least 8 hours, but not more than 24 hours, prior to conducting the percolation test. The hole
shall be refilled with water, if necessary, prior to final measurements. The time required for the water level
to drop 1 inch within the tower 6 inches of the percolation test hole shall be measured and reported to the
Department in MPI. The absorption area percolation rate shall be the average rate of the percolation tests
after the rate has stabilized in all of the percolation test holes. The percolation rate to be used for
absorption area sizing, as specified in Section 6.28.080(A)(2), shall be the average of the percolation
rates, using either the last measurement or the slowest measurement in each test.
March 8, 2008 Page 13
5. Alternate percolation test procedures may be approved by the Department, provided that the
alternate procedures are substantially equivalent to, or exceed the requirements of the test procedure
detailed in this section.
D. Soil Gradation Analysis
A representative sample of soil at the infiltrative depth shall be obtained from the soil profile hole or
boring. The sample shall be submitted to a laboratory qualified to complete a soil gradation analysis to the
200 sieve.
E. Depth to High Groundwater
As described in 6.28.060(6)(3), the depth to maximum high groundwater may be determined by direct
visual observation of infiltrated water in the soil profile hole or boring by a qualified geologist, PE, or
qualified field technician under the supervision of a qualified geologist or PE. Other methods may also be
used to locate depth to maximum high groundwater, including:
1. Observation of soil in a profile hole or boring for evidence of salts left by the groundwater table or
chemically reduced iron in the soil, as evidenced by a dull gray or mottled coloring;
2. Soil moisture tests indicating percent water saturation at the absorption area depth; or
3. Other scientific methods approved by the Department.
F. Time of Year
Soil profile holes or borings may be dug and percolation tests may be performed by a qualified
geologist, PE, or a qualified field technician under the direction of a qualified geologist or PE at any time
of the year, provided that percolation testing is not conducted in soils with temperatures less than 32
degrees Fahrenheit. In the winter, appropriate use of soil blankets and/or tents may be needed to prevent
freezing soils. Amaximum/minimum registering thermometer shall be used to record the minimum
temperature near one of the percolation test locations. Ambient air temperatures and soil temperatures
shal- be recorded during the percolation test. Temperatures shall be reported in the written results
provided to the Department.
G. Reports
Written results shall be provided for the soil profile hole or boring evaluation, including identification of
the constraining layer, groundwater observations, and the additional tests performed, including
percolation tests and soil gradation analysis. The written report shall be signed by a qualified geologist or
PE and shall be submitted to the Department as part of the permit application.
6.28.070 Septic Tanks -Sizing, Design Criteria, and Installation
A. Septic Tank Size
The septic tank capacity shall provide a minimum 30-hour retention time for the design flow, as
determined in Section 6.28.050, and shall provide the minimum liquid volume calculated by using one of
the following formulas:
March 8, 2008 Page 14
Where number of bedrooms is used to calculate design flow:
Volume =Total GPD x 2 persons x 1.5 x Number of Bedrooms x 30 hours
24 hours per day
Where:
Total GPD = 75 GPD for buildings with a living area < 6,000 sq. ft. and 100 GPD for buildings with a living area >
6,000 sq. ft.
Where fixture count is used to calculate design flow:
Volume =Total GPD x Number of Persons x 1.5 x 30 hours
24 hours per day
Where
Total GPD =The sum of the GPD per person associated with all identified fixtures from Table 6.28-2.
In all cases, the minimum liquid volume of a septic tank shall be no less than 750 gallons. The volume of
the tank shall be based on the liquid depth at the level of the outlet invert.
B. Septic Tank Design
1. Configuration
a. Septic tanks shall have a minimum of two compartments. The inlet compartment shall be a
minimum of one-half and a maximum of two-thirds of the total capacity of the tank, with a minimum 500-
gallon capacity. The secondary compartment of a septic tank shall have a minimum capacity of 250
gallons and a maximum capacity of one-half of the total capacity. The liquid depth shall be a minimum of
30 inches. The total depth shall be a minimum of 10 inches greater than the liquid depth. The transfer of
liquid from the inlet compartment to the secondary or successive compartments shall be made at a liquid
depth of at least 14 inches below the outlet invert, but not in the sludge zone. Rectangular tanks shall be
constructed with the longest dimensions parallel to the direction of the flow. Septic tanks that do not meet
these criteria will be allowed only with written approval from the CWQCD.
b. The installation of more than four septic tanks in series is prohibited.
2. Inlets and Outlets
The inlet and outlet on all septic tanks shall be provided with open-end sanitary tees constructed to
distribute flow and retain scum in the tank. The tees shall extend a minimum of 14 inches below the
inverts and shall be accessible from the access opening. Clear space of 1 inch shall be provided over the
top of the tees, unless fitted with an effluent filter. The bottom of the outlet invert shall be a minimum of 3
inches lower than the bottom of the inlet invert. The distance from the outlet invert to the underside of the
tank top shall be at least 10 inches. All inlet and outlet pipes shall be supported to prevent failure as a
result of settling.
3. Effluent Filters
All septic tank outlets shall be equipped with effluent filters placed directly in the outlet tee. The inlet
of the filter shall be placed in the clear water zone beneath the scum layer and above the sludge layer.
The bottom of the filter shall extend into the liquid a distance equal to approximately 40 percent of the
March 8, 2008 Page 15
liquid depth. The filter capacity shall equal the design flow for the system. Filters shall comply with
National Sanitation Foundation Standard 46, "Evaluation of Components and Devices Used in
Wastewater Treatment Systems." The filter shall be easily accessible for maintenance and inspection.
4. Access
All septic tanks shall be located in an area that is accessible for maintenance and pumping of
contents.
a. Access Openings
Each compartment of a tank shall be provided with at least one access opening. Such
opening shall be a minimum of 20 inches square or 20 inches in diameter. Where the septic tank exceeds
12 feet in length, an additional access opening shall be provided over the baffle wall. The access opening
risers on fiberglass tanks shall be of the same material as the tank and factory sealed to the tank.
b. Access Opening Covers
Access opening risers shall be provided with a fitted, watertight cover of concrete, cast iron or
other approved material capable of withstanding all anticipated loads. All non-ferrous access openings
shall be fitted with a permanent magnet or steel rebar bonded or cast onto the lid.
c. Access Opening Riser Joints
Joints on concrete risers and access opening covers shall be tongue-and-groove or shiplap
type and sealed watertight using cement, mortar, or bituminous compound. Methods of attaching
fiberglass or polyethylene risers shall be watertight and approved by the tank manufacturer for septic tank
applications.
C. Septic Tank Materials
All septic tanks shall be constructed and installed to withstand earth and hydrostatic pressures when
full and partially empty. Onsite fabrication of septic tanks requires submittal of plans and specifications
prepared by a PE for Department review and approval. All septic tanks shall be water tight. The
Department will require water tightness testing in accordance with ASTM C1227 for two-piece concrete
tanks with a joint below the liquid level.
1. Concrete
Concrete tanks shall be constructed of Portland Type I-II sulfate-resistant cement, with a
minimum 28-day compressive strength of 4,000 psi, with a water to cement ratio less than 0.5. Air
entrainment and addition of mesh reinforcement are recommended. The manufacturer's name and the
liquid capacity of the tank shall be permanently marked on the outside of the tank.
2. Fiberglass and Polyethylene/Plastic
Fiberglass reinforced plastic (FRP) and polyethylene/plastic septic tanks specifically
manufactured for septic use may be used if they are of durable construction. Bedding and backfill shall be
as recommended by the manufacturer or as specified by a PE.
3. Metal and Wood
Metal and wooden septic tanks are prohibited.
March 8, 2008 Page 16
4. Other Materials
Other materials that result in an adequate and durable construction and resist excessive
corrosion, decay, and leakage may be approved on a case-by-case basis by the Department.
D. Septic Tank Installation
1. General
All septic tanks shall be located per the minimum setbacks required under Section 6.28.040. All
tanks shall be installed to resist buoyancy when empty, particularly if they are installed in areas with the
potential for groundwater intrusion. All tanks shall be installed per manufacturer's recommendations, or as
specified by a PE. The tank shall be level within a tolerance of 1 percent.
2. Depth of Burial
The allowable burial depth of a septic tank will vary with the tank material. The maximum depth of
burial to the top of the tank shall be the lesser of the manufacturer's recommendation or 6 feet, unless
otherwise specified by a PE with supporting evidence of structural integrity and access.
3. Backfill
All concrete septic tanks shall be backfilled using material excavated from the trench that is free
of frozen lumps, organic material, and rocks larger than 6 inches in diameter. Backfill shall be placed in
no greater than 12-inch lifts, moistened, and compacted to 90 percent of maximum dry density, per ASTM
D 698. Septic tanks of other material types shall be backfilled in accordance with manufacturer's
recommendations. Septic tanks shall be covered with a minimum of 12 inches of backfill material and
access opening covers shall be buried no more than 8 inches below finished grade.
E. Connections
All installations shall be in accordance with the requirements of the International Plumbing Code. The
inlet and outlet pipe penetrations shall be sealed with Link-SealO sealant or equally flexible watertight
rubber boot.
F. Operation and Maintenance
Septic tanks shall be operated and maintained in accordance with Section 6.28.130.
6.28.080 Absorption Systems -Sizing, Design Criteria, and Installation
A. Absorption Area
1. The minimum absorption area shall be based on the capacity of the soil to absorb and treat
effluent and shall comply with the requirements of this Regulation. Where site constraints allow, the
maximum depth of the absorption area shall be no more than 4 feet below final grade to permit adequate
re-aeration of the soil and to meet the oxygen demand of the applied wastewater. Two formulas, as
provided below, may be used to calculate the absorption area.
2. The minimum absorption area in square feet (A) may be computed as a function of the design
March 8, 2008 Page 17
flow (Qo) a load factor (PLF) and the appropriate LTAR from Table 6.28-3, according to the formula:
QpXPLF
A=
LTAR
Where:
LTAR =Maximum Loading Rate from Table 6.28-3, based on the soil profile hole or boring texture of
the constraining soil layer.
Qo = 1.5 x 2 person/bedroom x 75 gallons/person/day (living area <_ 6,000 square feet); or
= 1.5 x 2 person/bedroom x 100 gallons/person/day (living area > 6,000 square feet); or
= 1.5 x average daily wastewater flow, as determined from Table 6.28-2.
PLF = 1.0
Table 6.28-3
Long-Term Acceptance Rate (LTAR)
Percolation Rate
(MPI)
Typical Soil Texture Maximum Long Te *m Acceptance
Rate
allons er s uare foot er da
<5 Gravel Not Suitable
1 - 5 Coarse to Medium Sand 1.30
6 - 10 Fine Sand to Loamy
Sand 1.20
11 - 20 Sandy Loam to Loam 0.72
21 - 30 Loam 0.50
31 - 40 Loam to Silty Loam 0.40
41 - 60 Clay Loam to Clay'` 0.30
> 60 Silty Clay Loam/Silty
Cla 0.20
" Soils without highly expansive clays.
'`* Interpolation between the Maximum Long Term Acceptance Rates provided above is
allowed.
3. The following formula shall be utilized to determine the absorption area in square feet. Absorption
area is a fu1n~ction of the design flow (Qo), a load factor (PLF), and the percolation rate (t):
A = PLF ~ Qp J-V l
Where:
Qp = As defined above.
PLF = 1.4
Note: For secondary or advanced secondary treatment system effluent, see Section
6.28.090(E) for the PLF that accounts for reduced organic loading.
t =Percolation rate in MPI.
4. Adjustments in absorption area to encourage innovative technology are addressed in Sections
6.28.090 through 6.28.100.
March 8, 2008 Page 18
B. Absorption System Siting
1. No absorption system shall be permitted in areas exhibiting any of the following conditions unless
a PE submits a written analysis (with all supporting calculations) to the Department clearly and
convincingly demonstrating the suitability of the system design for the site and the Department approves
such system:
a. Where the soil percolation rate is slower than 60 MPI or faster than 5 MPI;
b. Where the maximum high groundwater elevation is less than 4 feet below the bottom of the
proposed absorption area;
c. Where bedrock exists less than 4 feet below the bottom of the proposed absorption area; or
d. Where the ground slope exceeds 30 percent.
2. A designated area for absorption system replacement is recommended. The Department may
require replacement areas for tighter soils, where the percolation rate is slower than 60 MPI. For
environmentally sensitive areas, the Department may require a replacement area for any soil condition.
C. Absorption Beds
Absorption bed excavations shall be equipped with more than one distribution pipe or other dispersal
technology. The absorption bed width must be greater than 3 feet wide and shall be computed by using
the bottom of the absorption bed area with applicable reductions outlined in Section 6.28.080(K).
D. Absorption Trench Systems
Unless precluded by site constraints, absorption trenches shall be used in lieu of absorption beds.
Absorption trench excavations shall be 1 to 3 feet wide. Trench wall excavations shall be spaced with a
minimum of 6 feet of undisturbed soil between each trench. The absorption area of a trench shall be
computed by using only the bottom of the trench area with applicable reductions outlined in Section
6.28.080(K).
E. Gravelless Chamber Systems
All gravelless chamber systems shall be approved by the CWQCD and sized according to the criteria
given in the CWQCD approval letter or sizing criteria recommended by the Department, subject to area
reduction allowances in Section 6.28.080(K)(1). These systems shall be installed per the manufacturer's
specifications.
F. Serial Systems
A serial distribution system may be used in absorption trench systems. This type of system shall meet
the following requirements:
1. The bottom of each absorption trench and its distribution pipe shall be level;
2. An absorption trench or chamber system shall follow approximately the ground surface contours
so variation in absorption trench depth will be minimized;
3. There shall be a minimum of 6 feet (horizontal measurement) of undisturbed soil between
adjacent absorption trenches and between the septic tank or other treatment unit and the nearest
absorption trench; the horizontal distance from the side of the absorption trench to the surface of the
ground shall be adequate to prevent lateral flow and eruption of effluent above ground; and
March 8, 2008 Page 19
4. Adjacent absorption trenches shall be connected with a relief pipe or a drop-box arrangement so
that each upgradient trench fills with effluent to the top of the gravel or the top of the chamber before
flowing to the adjacent downgradient succeeding trenches.
G. Alternating Absorption Systems
Long-term resting by alternating absorption areas is recommended. A diversion valve or other
approved diversion mechanism may be installed on a septic tank effluent pipe to allow alternating
absorption systems to operate. The diversion mechanism shall be readily accessible from the finished
grade and shall be switched on an annual basis. Each absorption area shall be a minimum of 50 percent
of the total required absorption area.
H. Dry Wells
1. Dry wells may be permitted as an alternative when absorption trenches and beds are not
possible, where the top 3 or 4 feet of soil is underlain with porous sand or other suitable soil, and where
the subsurface conditions are otherwise suitable for dry well installations. Secondary treatment is required
when dry wells are used for the absorption system.
2. Dry wells shall meet these criteria
a. Dry wells shall be filled with clean, graded rock that may range in size from '/z to 2-'/2 inches
in diameter. The rock shall extend from the bottom of the well to at least 2 inches above the inlet pipe.
b. At least one 4-inch perforated vertical standpipe shall be attached to the end of the
distribution pipe with a tee fitting. It shall extend to the bottom of the dry well and up to the finished grade
and be fitted with a removable cap to be used as an inspection pipe. The removable cap shall be fitted
with a permanent magnet sealed to the underside of the lid with waterproof glue or epoxy, to aid in
locating the inspection pipe.
c. The absorption area of the dry well shall be computed on the basis of percolation rates or the
LTAR of each stratum penetrated, using the formulas specified in Section 6.28.080(A). The weighted
average of the results shall be used to obtain a design flow value. The effective absorption area of the
well shall be calculated by adding the area of the sidewalls below the horizontal inlet pipe and the area of
the bottom of the well, excluding any impermeable stratum penetrated. Dry wells shall only be permitted
in soils with a percolation rate faster than 60 MPI.
d. Dry wells shall be separated by a distance equal to the depth of the excavation, three times
the diameter of the largest dry well, or 10 feet, whichever is greater.
e. The sidewalls of the dry well shall be scarified, and any smeared or compacted surfaces shall
be removed.
f. A covering of geotextile fabric or other approved permeable material shall be placed over the
aggregate before the dry well is covered with soil.
g. The backfill material shall be graded to deflect precipitation and surface drainage.
I. Pipe and Gravel System Materials and Construction
1. All pipes used in OWTSs shall be constructed of compatible pipe, bonding agent, and fittings. The
following may be used: a) plastic pipe and fittings with a minimum wall thickness conforming to ASTM
Standard 3034, SDR35, or equivalent, b) perforated distribution pipe surrounded by rock within an
absorption system with a minimum wall thickness conforming to ASTM Standard 2729, or c) corrugated
March 8, 2008 Page 20
polyethylene pipe with a smooth interior meeting ASTM F405 and AASHTO M252 specifications or
equivalent.
2. Piping within absorption beds shall be installed so that the pipes are a maximum of 6 feet from
center to center.
3. Distribution pipes installed on the edge of an absorption bed shall not be further than 3 feet, nor
less than 1 foot from the wall of the absorption bed.
4. A minimum of 6 inches of gravel and aggregate ranging in size from '/ to 2-'/ inches shall be laid
into the trench or bed below the distribution pipe elevation. The aggregate shall be evenly distributed a
minimum of 2 inches over the top of the distribution pipe. The aggregate shall be covered with separation
fabric. Building paper shall not be used to cover the aggregate.
J. Dosing and Pumps
1. Dosing by siphon or pumps may be used in conjunction with absorption systems and must be
designed by a PE.
a. Dosing is required when the absorption area of a system exceeds 2,000 square feet and for
all commercial facilities.
b. Pressure dosing systems are required for mound systems and sand filter systems.
2. The following criteria shall be met:
a. A dosing or pumping chamber shall be required for OWTSs equipped with dosing devices.
The chamber shall be watertight to preclude the entrance of ground and surface water. The chamber
shall be fabricated or constructed of monolithic concrete, fiberglass-reinforced plastic, polyethylene, or
other approved materials.
b. The chamber shall have an access opening with a minimum dimension of 20 inches. The top
of the access opening shall extend to finished grade.
c. The dosing device or pump design shall be adequate to distribute effluent throughout the
entire system and prevent clogging, but it shall not produce pressures that will disrupt materials within the
absorption area or mound. The dosing device design shall not hydraulically overload the soils.
d. Dosing siphons shall be approved by the Department prior to issuance of a permit.
e. The second compartment of a septic tank may be used as a dosing or pumping chamber
provided that it can be shown that the minimum 30-hour detention time will not be decreased and the
pump is screened or provided with an approved filtering device to ensure that only liquid effluent will be
discharged.
f. Dosing systems shall be designed by a PE. Specifications shall be submitted to the
Department by the applicant with the OWTS design. Specifications shall include the manufacturer's
pump performance curve for the selected pump, showing capacities, heads, and efficiencies for the
entire operating range of the pump. Additionally, the following criteria must be met:
i. The non-clog pump opening shall have at least a 2-inch diameter solids-handling
capacity where raw wastewater is pumped, or a maximum of %-inch diameter solids handling capacity
where previously settled effluent is pumped.
March 8, 2008 Page 21
ii. Automatic liquid level controls shall be provided to start and shut off pumps at a
frequency required by the design.
iii. Pressure pipe shall be of sufficient strength to accommodate the pump discharge
pressure.
iv. Automatic air re-ease valves shall be installed at high points in the pressure pipe where
necessary to prevent air locking.
v. The chamber containing the pump shall be sized to allow pump cycling commensurate
with the pump design capacity.
vi. The discharge pipe from the dosing or pumping chamber shall be protected from freezing
by burying the pipe below frost level or sloping the pipe to allow it to be self-draining.
vii. The pump shall be equipped with an audible and visible alarm to alert the owner of a
pump failure or malfunction.
K. Reduction Allowances
1. When gravelless chamber systems are used, reductions shall be limited to only those systems
approved through the CWQDD certification. The maximum reduction allowed for selection of gravelless
chamber systems shall be 30 percent for an absorption trench and 10 percent for an absorption bed.
2. A reduction in absorption area may be made for gravel depth in excess of 6 inches below the
bottom of the distribution pipe. The deep gravel reduction shall not be used if the absorption trench
reduction is used. The reduction is calculated according to the following formula:
Lx (W+2)/(W+ 1 +2d)
L =Length required prior to adjustment.
W =Width of trench or bed, in feet.
d =Depth of gravel below distribution pipe, in feet.
3. A reduction in absorption area shall be allowed for the use of secondary or advanced secondary
treatment, as specified in Section 6.28.090(E).
4. When a dosing system is installed, the square footage of the absorption area may be reduced by
20 percent, except that no dosing system sizing credit shall be allowed for mound systems or sand filters.
5. No reduction in sizing shall be allowed for installed water conservation devices.
6. The maximum reduction from all combined alternatives shall be no greater than 50 percent of the
standard required absorption area for absorption trench systems and shall be no greater than 30 percent
for absorption bed systems. Allowable reductions are summarized in Table 6.28-4 below:
March 8, 2008 Page 22
Table 6.28-4
Summary of Allowable Reductions
Trench Bed
Pipe and Gravel 10% 0%
Dosing 20% 20%
Chambers (between 5 - 60 MPI) 30% 10%
MAXIMUM REDUCTION
ALLOWED 50% 30%
L. Distribution Pipes
Distribution pipes must meet the following criteria:
1. Distribution pipes shall be of sufficient strength to accommodate pump discharge pressure, and
the pipes shall be sized to maintain a minimum velocity of 2 feet per second.
2. All distribution pipes used in OWTSs shall meet the requirements specified in Section
6.28.080(1)(1). Tile, open-joint pipe, and cast iron pipe may not be used in OWTSs. The sewer and
effluent pipes to the distribution box or manifold and absorption area shall be constructed of solid-wall
watertight pipe. Only distribution piping laterals may be plastic perforated pipe.
3. Distribution pipes for gravity systems shall be a minimum of 4 inches in diameter and of
sufficient size to equally distribute effluent throughout the entire absorption area. The pipes for gravity
systems shall be a maximum of 100 feet in length, unless otherwise approved by the Department.
4. Building sewer and effluent pipe using gravity shall be laid with a fall of %4 inch per foot, or with
the minimums given in the International Plumbing Code for the pipe diameter.
5. Distribution pipes in absorption systems shall be level.
6. Distribution pipes shall be looped at the ends or have the ends plugged or capped.
M. Vents and Observation Pipes
1. Absorption areas shall be provided with observation pipes to allow observation of effluent
ponding.
2. Vents and observation pipes shall be a minimum of 4 inches in diameter.
3. Observation pipes shall be accessible (with "as-built" locations provided to the Department) and
shall be placed at each corner of an absorption bed or at the ends of each absorption trench.
4. Observation pipes shall extend to the bottom of the aggregate with perforations in the
aggregate, or into the cutouts provided in the gravelless chambers.
5. A removable cap or plug shall be installed in each observation pipe to allow access for
inspection of the absorption area. If the observation pipe is cut to ground level, the cap shall be fitted
with a permanent magnet or steel rebar.
March 8, 2008 Page 23
N. Cleanouts
A cleanout shall be provided within 5 feet of a building and in each subsequent 100 feet of building
sewer, or at every change of direction greater than 45 degrees. Cleanouts shall be installed so that they
open to allow cleaning in the direction of the wastewater flow, or shall be two-way ceanouts, at the
discretion of the PE responsible for the design.
O. Distribution Valves or Distribution Boxes
1. Distribution valves may be used to distribute the effluent to the lateral pipes of the system.
2. Distribution boxes, if used, shall be of adequate size to accommodate the system's distribution
pipes and to equally distribute effluent to the absorption area. Flow levelers may be provided to balance
the flow between the pipes. Distribution boxes shall be constructed with the inlet hole at least 1 inch
above the level of the outlet hole. The outlet invert shall be 3 to 6 inches above the floor of the distribution
box. A permanently installed baffle plate, or comparable approved device shall be installed at the inlet to
adequately slow liquid entering the distribution box to stabilize the effluent before it enters the absorption
area. The distribution box shall be filled with water to check the level and check for leaks at the time of
inspection, prior to backfilling.
3. The distribution box shall be constructed on a level base. Surface access to the distribution box is
required (because the distribution box is subject to movement from freeze and thaw). Regular
maintenance is also required to keep the box level.
P. Construction in Adverse Weather Conditions
Absorption systems shall not be installed where the soil at the system elevation is frozen or saturated.
Snow cover shall be removed from the absorption area before excavation begins. Snow shall not be
placed in a manner that will cause water to pond on the absorption system area during snow melt.
Excavated soil to be used as backfill shall be protected from freezing; excavated soil that freezes solid
shall not be used as backfill. The backfill shall be loose, dry, unfrozen soil. When systems are installed
during adverse weather conditions, such as periods of heavy rain and winter weather, the excavation
area shall be inspected by a PE prior to installation of the absorption system, and backfill material shall be
inspected at the time of placement. The PE shall provide written documentation to the Department
verifying the inspection(s).
6.28.090 Other Systems
A. Mound System
1. General Design Requirements
A mound system may be appropriate for use in areas of high groundwater or where depth to
shallow bedrock is 4 feet or less. Mound systems shall be designed by a PE. The design shall be site-
specific and include absorption area size calculations, specifications for the fill material, distribution pipe,
cap, topsoil, final grading, and such other information pertinent to the construction of the system as may
be requested by the Department in connection with a permit application. The PE shall, in all cases, submit
a detailed plan and cross-sectional view of the system, with dimensions specified.
March 8, 2008 Page 24
2. Absorption Area
a. The underlying native soil surface shall be left in place with a rough, open surface. Any
smeared and compacted surfaces shall be removed. Sizing of the basal absorption area of the mound
system shall be in accordance with Section 6.28.080(A).
b. The filter material used in the construction of a mound system shall be a clean, coarse sand,
as specified in Section 6.28.090(B)(2)(b), with a minimum depth of 2 feet. If sand filter material is used,
sizing shall be in accordance with 6.28.090(B)(2)(a).
c. At the discretion of the PE and as approved by the Department, suitable native soil may be
used in conjunction with or as a substitute for sand filter material. If native soil is used as filter material,
sizing shall be in accordance with Section 6.28.080(A), with a minimum application rate of 0.95 gallons
per square foot per day, or the comparable percolation rate of 28 MPI. The fill must be verified as
suitable filter material by compaction tests to confirm uniformity and percolation tests to confirm
absorption characteristics. The native soil may not have more than 30% material less than a No. 200
sieve.
d. If the basal area of the mound system has a slower MPI or an LTAR less than the filter
material, the calculations submitted with the permit application must clearly demonstrate how this
difference has been taken into account in calculating the size of the absorption area.
e. The absorption area shall be placed with the long axis perpendicular to the natural slope of
the terrain. Whenever possible, long, narrow mounds shall be used on sloped sites to minimize the linear
loading rate. The final slope of the mound backfill shall be no greater than 3:1, unless a liner is used.
f. No reduction shall be taken in absorption area size for a chamber system or dosing on a
mound system.
3. Effluent Application Rate and Method
a. The dosing frequency for the application of effluent to the mound system absorption area
shall be determined based upon an analysis of the percolation data and/or a soil texture analysis of the
native soil at the point of interface between the filter material and the native soil.
b. A pressure distribution system is required for effluent application using a mound system. A
solid force main pipe with perforated laterals shall be used to distribute effluent uniformly throughout the
absorption area. Lateral pipes shall be level (± 0.1 foot). The spacing and size of the perforations in the
lateral pipes shall be at the discretion of the PE designing the system, provided that they shall provide
uniform application of effluent. The distribution system shall be constructed to drain back to the dosing or
pumping chamber, to the absorption system, or be buried below the frost line. Orifices shall be no
smaller than 3/16 inch unless preceded by secondary treatment. All laterals shall have flushing valves.
4. Absorption Area Aggregate; Chambers
a. Where chambers are not used, the mound system absorption area shall be constructed of an
aggregate layer of the gradation specified in Table 6.28-5 over the filter material.
Table 6.28-5
Gradation of Mound System Absorption Area Aggregate
Sieve Size Percent b Wei ht Passin Sieve
2'/2 inch 100
'/< inch 0 - 20
No.4 0-3
March 8, 2008 Page 25
b. The layer of aggregate shall be spread over the entire layer of filter material so that a minimum
of 6 inches of aggregate is below the distribution system and a minimum of 2 inches of aggregate is
above the distribution system. The bottom and top of the aggregate shall be level within ± 0.2 feet. The
bottom edge of the aggregate shall be considered the edge of the absorption area when measuring
minimum distances.
c. When chambers are utilized in lieu of aggregate, the mound filter material must be adequately
stabilized or provisions made to prevent the chambers from settling into the sand.
5. Use of Liners
Where the side slope of the mound is less than 3:1, no liner on the sidewall is required. Where
side slopes are steeper than 3:1, a 20-mil (0.5 millimeter) liner of PVC or equivalent material shall be
used on the sidewalls to prevent lateral flow. The liner must extend at least 12 inches into the original
grade or below the bottom of the absorption area, whichever is deeper. The Department may allow a
retaining wall with a liner to prevent lateral flow. The retaining wall structural design shall be included with
the mound system design.
6. Soil Cover
An approved separation fabric or other approved permeable material shall be placed over the
absorption area aggregate before the distribution pipe of a mound system is covered with soil. A
minimum of 1 foot of soil shall be placed over the aggregate area, or chambers, and the surrounding filter
material. The mound shall be sufficiently crowned/adequately sloped to promote good runoff (but shall
not exceed 3:1). The surface of the mound system shall extend at a minimum slope of 2 percent for a
minimum of 2 feet beyond the outermost edge of the absorption area, before the side slope begins to
provide positive drainage off of the mound surface. Soil cover shall enable revegetation of the area in
accordance with Section 6.28.110. In the event that topography precludes a 3:1 side slope from the
mound, a retaining wall or liner may be used. The PE shall design the retaining wall with consideration of
soil surcharge and hydrostatic pressure.
B. Sand Filter
1. General Design Requirements
The use of sand filters may be appropriate in areas where the soil profile hole exhibits a
constraining layer making the soil unsuitable for absorption systems using the native soils. Sand filters
shalt be designed by a PE. Sand filters may be installed subsurface or above natural grade. In all cases,
the top of the sand bed shall be a minimum of 4 feet above maximum high groundwater or bedrock.
2. Absorption Area
a. The minimum area for a sand filter shall be computed as a function of the design flow. An
application rate of 0.95 gallons per square foot per day, or the comparable percolation rate of 28 MPI,
shall be used.
b. The filtering material shall be clean, coarse sand with 100 percent passing a No. 4 sieve. The
sand shall have an effective size between 0.25 and 0.6 millimeters. The uniformity coefficient shall be 4.0,
or less. A gradation of the filter material shall be submitted to the Department prior to final approval of the
system. In the event the foregoing gradation of sand is not commercially available, alternative sand
specifications will be evaluated by the Department on acase-by-case basis.
March 8, 2008 Page 26
c. The sand shall be at least 2 feet thick below the distribution gravel or base of chambers.
When chambers are utilized, the sand will be adequately stabilized or provisions made to prevent the
chambers from settling into the sand. Where aggregate is used, distribution pipes shall be surrounded by
coarse, screened gravel or crushed stone aggregate meeting the requirements in Section 6.28.090(A)(4).
The separating distance between parallel distribution pipes shall be less than 6 feet, and a distribution
pipe shall be located within 3 feet of each filter sidewall. The distribution pipe shall meet the requirements
of Section 6.28.080(L). The sand shall be thoroughly settled by flooding or other means before the
distribution pipe or chambers are placed on the filter material.
d. No reduction shall be taken in absorption area size for a chamber system or dosing on a
sand filter.
e. Other absorption area construction details, such as use of liners and soil cover, shall be in
accordance with Section 6.28.090(A)(5) and (6).
3. Effluent Application Rate and Method
A pressure distribution system is required for effluent application in a sand filter system. A solid
force main pipe with perforated laterals shall be used to distribute effluent uniformly throughout the
absorption area. Lateral pipes shall be level (± 0.1 foot). The spacing and size of the perforations in the
lateral pipes shall be at the discretion of the PE designing the system, provided that they shall provide
uniform application of effluent. The distribution system shall be constructed to drain back into the dosing
or pumping chamber, to the absorption area, or be buried below the frost line. Orifices shall be no
smaller than 3/16 inch unless preceded by secondary treatment. All laterals shall have flushing valves.
C. Constructed Wetland
1. Constructed wetlands shall be installed only where there will be adequate flow to support the
wetlands. Additionally, constructed wetlands shall only be installed on parcels with a designated
replacement area that can accommodate a traditional OWTS in the event that the constructed wetland
fails and cannot be repaired.
2. A constructed wetland shall be designed by a PE. The design shall be site-specific and include
specifications for loading, capacity, liner material, treatment cell media, density and species of plant
material, effluent level, final discharge location, and any other pertinent information requested by the
Department in conjunction with a permit application. Minimum requirements for constructed wetlands
include the following:
a. All constructed wetlands shall be designed for subsurface flow through the absorption area.
Designs shall conform to the details in the U.S. Environmental Protection Agency's Subsurface Flow
Constructed Wetlands for Wastewater Treatment, A Technology Assessment (EPA 832-R-93-008).
b. Liners shall be watertight membranes of at least 30 mils (0.75 millimeter) thickness and must
be PVC or material of equal or greater integrity.
c. A level control structure that allows for the altering of water level or complete drainage of
water from the wetland shall be installed in each wetland treatment cell.
d. Neither the common reed (Phragmites communis), purple loosestrife (Lythrum salicaria), nor
cattails (Typha latifolia) shall be intentionally planted within a constructed wetland.
e. The minimum residence time within the constructed wetland shall not be less than four days
for residential sewage flows.
f. The length to width ratio of a constructed wetland shall not exceed 5:1.
March 8, 2008 Page 27
g. Designs shall include estimates of effluent quality at the inlet and outlet
h. Access points for sample collection shall be provided for treated effluent prior to discharge
from the wetland treatment cell.
3. There shall be no discharge of effluent on the surface, or off a property unless a CDPS permit
has been obtained from the CWQCD. If such a permit is obtained, the property owner(s) shall monitor
system effluent in accordance with the CDPS permit requirements prior to discharging to waters of the
State.
D. Aerobic Wastewater Treatment System
Aerobic wastewater treatment systems shall be ANSI/NSF approved, designed by a PE and meet the
following requirements:
1. The method of aeration shall be by mechanical aeration, diffused air, or a combination of both.
Aerobic conditions shall be maintained at the maximum organic loading in both the aeration and settling
compartments at all times.
2. The system's aeration compartment, inlet and outlet arrangements, baffling, and air application
shall meet these requirements: a) allow for intimate mixing of applied wastewater, return solids, and
applied air, b) prevent excessive short-circuiting of flow, and c) prevent the deposition and buildup of
solids in the aeration compartment. The aeration compartment shall not be installed upstream of the
septic tank.
3. A warning device indicating aeration unit failure shall be installed.
4. The effluent discharge shall be accessible for sample collection.
E. Secondary Treatment and Advanced Secondary Treatment
Prior to the final dispersal stage of an OWTS, the Department may require secondary or advanced
secondary treatment of effluent. Conditions that may trigger this requirement include: 1) areas with a high
density of OWTSs and/or aging OWTSs, 2) areas in close proximity to groundwater, a drinking water
supply, water courses and/or steep slopes, 3) areas where systems encroach on setbacks specified in
Section 6.28.040, 4) commercial or industrial uses, or 5) where deemed necessary by the Department to
protect public health and the environment, such as those areas specified in Section 6.28.180. Secondary
or advanced secondary treatment systems include ANSI/NSF Standard 40 Class 1 units, which shall be
approved by the CWQCD prior to use. Effluent from the units shall be discharged into an absorption
area, sand filter, or mound system. The minimum absorption area for effluent from secondary or
advanced secondary treatment may be calculated using a P~F of not less than 1.0 when the percolation
rate formula is used.
F. Wastewater Pond
Wastewater ponds are strongly discouraged; however, a wastewater pond may be used, at the
discretion of the Department, to provide an additional degree of treatment following primary treatment.
Wastewater ponds shall be designed by a PE and shall meet the following criteria:
1. A wastewater pond shall be designed for a loading not to exceed 0.46 pounds per day of BOD5
per 1,000 square feet of water surface area. The PE shall specify aeration requirements to avoid
excessive plant growth and odors.
2. Water depth in a wastewater pond shall be a maximum of five feet. The inside slope of the pond,
dike, or embankment shall not be steeper than 2:1. A center inlet shall be provided.
March 8, 2008 Page 28
3. Unless four feet of impervious soil or solid, unfractured rock exists beneath the bottom of a
wastewater pond, the pond shall be sealed to prevent seepage of wastewater. Only ponds exhibiting an
exfiltration rate of 1 x 10_s cm/sec or less shall be deemed adequate to prevent excess seepage.
4. Adequate safety protection shall be provided, such as fencing and signs, to protect against
personal injury and damage by wildlife.
5. Surface runoff shall be diverted away from a wastewater pond.
Any OWTS permit application that includes a wastewater pond shall specify how the pond discharge shall
be treated by a soil absorption system or other final treatment system. Surface discharge from the pond is
prohibited unless allowed under a CDPS permit obtained from the CWQCD. The PE shall provide an
operation and maintenance manual based on a 50-year planning horizon.
G. Evapotranspiration System
Lined evapotranspiration systems are prohibited in Pitkin County due to the extended snowpack
period and because precipitation exceeds evaporation four to five months of the year.
H. Evapotranspiration/Absorption System
1. General Criteria
Evapotranspiration/absorption systems may be designed using either the water balance method
or subsurface drip system design described below. The exclusion of lined ET systems prohibits the use
of an ETA for shallow groundwater conditions. ETA systems shall be designed by a PE and shall meet
the following criteria:
a. An ETA system shall be located in an area where there is unobstructed exposure to sunshine.
b. The system design must include soil and site conditions under which system installation is
unacceptable.
c. The absorption area shall be crowned and covered with a minimum of four inches of selected
backfill material and a vegetative cover.
d. Flow rates shall be based upon the number of bedrooms or fixtures.
2. Water Balance Method
a. An ETA system may be designed on the basis of a monthly water balance for the system.
Such a design shall provide for total storage of average daily flows for all periods in which
evapotranspiration/absorption is not shown to occur. The maximum allowable soil absorption rates using
the water balance method are described in Table 6.28-6:
March 8, 2008 Page 29
Table 6.28-6
Soil Absorption Rates Using the Water Balance Method
Percolation Rate (MPI) Max. Allowable Soil Absorption Rate (gal/sq. ft(day)
61 - 90 0.20
91 -120 0.15
121+ 0.10
b. If the water balance method is selected, the PE shall provide information regarding monthly
wastewater flow into the system, monthly precipitation infiltrating into the system, initial moisture content
in bed sand and topsoil cover, monthly evapotranspiration rate, amount of water absorbed into the soil,
and storage capacity of the absorption bed (in gallons) in the form of a table or spreadsheet. Monthly
precipitation and evapotranspiration shall be from a reputable source, such as the National Oceanic and
Atmospheric Administration.
c. Sand utilized in ETA systems shall meet the gradation requirements in Table 6.28-7. Sand
shall be well graded as defined by ASTM D2487. The design engineer shall approve imported sand prior
to delivery of material to the site. Gradation results of sand material shall be in conformance with this
section and shall be submitted to the Department prior to final approval.
Table 6.28-7
Gradation Requirements for Sand Used in ETA Absorption Beds
Sieve Size Percent % Passin
No. 4 100
No. 40 50 - 55
No. 200 <15
d. Gravel shall be clean 1/2 inch to 2-1/2 inch rock.
e. If distribution pipe is used, separation shall not exceed 6 feet. If chamber units are used, they
shall be spaced to provide an equal or greater amount of storage within the ETA absorption area than
would be provided by gravel.
f. Topsoil material sha11 be selected or mixed to provide a cover that will promote movement of
water to the surface and provide a good vegetative base. Appropriate revegetation to promote
evapotranspiration shall be included in the permit application as part of the system design or revegetation
plan. Trees should not be planted in any location which will eventually shade the ETA system. The ETA
system shall be protected to prevent damage from vehicular, pedestrian or equestrian travel.
g. A diversion ditch and/or berm shall be provided on the uphill side(s) of the absorption area to
deflect precipitation and other outside water away from the ETA system. All surface drainage must be
diverted around the absorption area and the absorption area must be sufficiently crowned to provide good
runoff.
3. Subsurface Drip System
A subsurface drip system shall meet the following minimum requirements:
March 8, 2008 Page 30
a. Drip pipe shall be installed between 12" and 30" below grade.
b. Dosing shall be between 30% and 50% of the volume of the perforated pipe per dose.
c. The ETA system absorption area shall have a minimum of four sections.
d. The effects of soil permeability (percolation rate), slope and final vegetative cover and erosion
control must be addressed by the design.
e. Design criteria shall estimate the percent allocation by evaporation, transpiration and
absorption.
f. No irrigation shall be allowed over the ETA system's absorption area.
6.28.100 New Technology System
A. Certification
Upon notice of certification by the CWQCD, the Department may consider a permit application for a
new technology system in the same manner as applications for systems that treat and disperse effluent
through an absorption system.
B. Design and Field Testing
A new technology system shall be designed by a PE and a permit application shall include such
design specifications and testing data as the Department deems necessary to evaluate the proposed
system. The applicant shall agree to conduct, at the applicant's expense, such field testing of the
proposed system as the Department shall require to ensure that the system functions properly and
creates no hazard to public health or the environment.
C. Backup System
Any application for a permit for a new technology system shall provide for the installation of a backup
system of a type described in this Regulation or certified by the CWQCD. In the event that the
Department determines that the proposed system is not functioning properly, or is otherwise creating a
hazard to public health or the environment, the applicant shall install the backup system. The requirement
of a conventional backup system may be waived if the Department has adopted criteria that state that no
backup system is required for the new technology system in question.
6.28.110 Revegetation of All OWTS Sites
A. Revegetation Requirements
An adequate layer of good quality topsoil capable of supporting revegetation shall be placed over the
entire disturbed area of an OWTS installation. The topsoil may be part of the minimum required cover
depth of 1 foot. The topsoil shall be planted with a mixture of native grass seed that has good soil
stabilizing characteristics (but without taproots), provides a maximum transpiration rate, and competes
well with primary successional species. No trees or shrubs, or any vegetation requiring regular irrigation,
shall be planted over the area. All seed mixtures utilized for revegetation must be certified weed free and
approved by Pitkin County Land Management (as confirmed by inclusion in The Pitkin County
Revegetation Guide).
March 8, 2008 Page 31
B. Maintenance of Vegetation
Until vegetation is reestablished, erosion and sediment control measures shall be implemented and
maintained on site. The owner(s) of an OWTS shall be responsible for maintaining proper vegetative
cover and may be required to remove inappropriate materials and properly revegetate any time a violation
is found to exist.
6.28.120 Construction Observation by a PE
For all OWTSs designed by a PE, construction observation is required. The PE shall inspect and field
verify the alignment, elevation, and grade of manifold and distribution pipes to assure that they conform to
the approved plans. The PE shall be required to submit a report to the Department documenting that this
work was performed in general conformance with the design prior to obtaining the Department's final
approval for the system. All OWTS component locations shall be documented in a manner that is
compatible with County GIS mapping and shall be reported to the Department with final "as-built"
information from the PE.
6.28.130 Operation and Maintenance
A. Responsibility
The property owner(s) or occupant(s) shall be responsible for operation and maintenance of each
OWTS servicing their property unless responsibility for operation and maintenance has been transferred
to a public, quasi-public, or political subdivision. The property owner(s) or occupant(s) shall be
responsible for field locating the septic tank, its access ports, and any of the components of the system at
the request of the Department and within one week of such a request. It shall be the responsibility of the
property owner(s) or occupant(s) to maintain service contracts for manufactured units and alternating
absorption systems, and to require that the service provider notify both the property owner(s)/occupant(s)
and the Department if the service contract is terminated for any reason. The obligations of the property
owner(s) and occupant(s) under this Section 6.28.130 shall be joint and several.
B. Service Label
For all manufactured units or other OWTSs under a service contract, a clearly visible, permanently
attached label or plate giving instructions for obtaining service must be placed at a conspicuous location.
C. Operation and Maintenance Manual
The PE designing the system shall be required to provide an operation and maintenance manual to
the property owner(s) and the Department before obtaining final Department approval and before the
system commences operation for the following types of OWTSs: 1) manufactured units, 2) aerobic
wastewater treatment systems, 3) secondary treatment systems, 4) advanced secondary treatment
systems, and 5) new technology systems. The manual shall incorporate "as-built" details and a statement
by the PE that system components have been constructed in accordance with design plans and
specifications and shall specify routine system inspection and cleaning frequency. The manual shall also
specify procedures for removing the OWTS from service.
D. Maintenance, Cleaning, and Inspection
1. Subject to subparagraph (A) above, the owner(s) of a system or the occupant(s) on a property
served by an OWTS shall be required to maintain and clean the OWTS. Maintenance and cleaning of
systems to ensure proper functioning is recommended to occur with the frequency designated in Table
6.28-8 and shall be conducted by licensed systems cleaners and/or inspectors. The Department may
require periodic submittal of proof of proper maintenance and cleaning, particularly in environmentally
sensitive areas of the County or areas with other risk factors described in Section 6.28.180. For OWTSs
March 8, 2008 Page 32
maintained and cleaned at a frequency less than specified in Table 6.28-8, the property owner(s) or
occupant(s) shall provide an explanation of why a lesser frequency is warranted, if requested by the
Department.
2. Each OWTS shall have suitable access ports to permit periodic inspection and maintenance of all
tanks, chambers, vaults, and other components, such as submerged bearings, moving parts, tubes,
intakes, slots, filters, inlet and outlet baffles, and other devices. Such access ports shall also enable
collection of samples from tanks, chambers, and vaults.
Table 6.28-8
Maintenance and Cleaning Frequency
Type of Component Inspection/Maintenance Cleaned or Pumped
Septic Tanks Every 2 Years Every 2 Years, or As
Needed
Vaults, Privies When Pumped At 80% Capacity
Secondary Treatment Systems;
Advanced Secondary Treatment
S stems; Other Manufactured Units Every 6 Months Per Manufacturer's
Recommendation
Absorption Areas Every 6 Months N.A.
Dosing or Pumping Chambers Every 6 Months Every 4 Years
Constructed Wetlands As Specified by PE Designing the
S stem N.A.
New Technology Systems Every 6 Months or More Frequent
if Recommended b PE Per Manufacturer's
Recommendation
E. Monitoring and Sampling
The Department may require the owner(s) or occupant(s) to collect and test effluent samples from
OWTSs when monitoring of effluent is Necessary to ensure compliance with the provisions of this
Regulation. Monitoring shall not be required more than twice a year, except when required by the
Department in conjunction with an enforcement action, or as agreed to by the owner(s) or occupant(s).
The collection of the effluent samples from the OWTS shall be performed by a qualified environmental
professional, and the effluent samples shall be tested by a qualified water quality laboratory. The
laboratory results shall be delivered to the Department. Expenses associated with such monitoring and
testing shall be borne by the owner(s) or occupant(s) of the property.
F. Disposal of Waste Materials
Disposal of waste materials removed from a system in the process of maintenance or repair shall be
disposed of at a site and in a manner that complies with state regulations (5 CCR 1003-7 and 6 CCR
1007-2, Part 1), the federal standards for the use or disposal of sewage sludge (40 CFR 503) and any
other applicable federal, state or local rules and regulations in the jurisdiction where disposal will occur.
G. Discharge Quality and Permits
No wastewater or effluent may be discharged on the surface of the ground or into waters of the State
unless the OWTS and effluent meet the minimum requirements of this Regulation and proper discharge
permits have been obtained from the CWQCD.
March 8, 2008 Page 33
H. Termination of Use
1. Aseptic tank, vault, or holding tank shall be removed from service by: a) pumping the contents of
the tank, b) capping the inlet and outlet pipes, and c) either removing or crushing the tank, or filling the
tank with screened rock, compacted soil, or other inert materials.
2. An absorption system shall be abandoned in place by disconnecting and capping the inlet pipe to
the bed, trench, mound, evapotranspiration/absorption, or evapotranspiration system.
3. Anon-vaulted privy shall be abandoned by pumping any liquid material from the privy pit, then
backfilling the pit with inert materials. The privy structure may remain in place, provided that the stool is
removed and a solid floor placed in the structure.
4. All manufactured units, aerobic wastewater treatment systems, secondary treatment systems,
advanced secondary treatment systems, and new technology systems shalt be removed from service in
accordance with procedures specified in the system's operation and maintenance manual, as specified in
Section 6.28.130(C).
5. For all OWTSs, the system shall be removed from service in a manner that is protective of public
health and the environment and contaminated soils and waste materials disposed of in accordance with
subparagraph (F) above.
6.28.140 Miscellaneous Systems; General Prohibitions
A. Grey Water Systems
1. A grey water system shall meet the minimum design and construction standards for an OWTS.
Average daily wastewater flow shall be determined by reference to Table 6.28-2 (including a bedroom
count for all dwellings). For grey water treatment in an absorption system, a P~F of not less than 1.0 shall
be used when the percolation rate formula is used.
2. There shall be no surface discharge or land application of effluent unless a CDPS permit is
obtained from the CWQCD and the effluent is periodically tested to ensure compliance with applicable
standards for such surface discharge, as described in Section 6.28.040(8)(6). Sampling ports or other
means of effluent sampling shall be required for irrigation use. All sampling and testing costs are the
responsibility of the property owner(s) or occupant(s).
B. Vaults
Vaults are not permitted except where building use/occupancy is limited (and in no event shall use be
more than 60 days per year) and located on a property where installation of a traditional OWTS is not
physically feasible. Vaults shall meet the same construction and installation standards required for septic
tanks, except that there shall be no effluent outlet and two-compartment construction shall not be
required. Vaults shall have a minimum 1,000 gallon capacity. Vaults shall be located in an area that is
accessible to pumping and shall be equipped with a conspicuously located visual and audio device to
signal when filled to 80 percent of capacity. Vaults shall be pumped by a licensed systems cleaner prior to
reaching capacity, and receipts shall be retained and provided to the Department upon request.
C. Vault Privies
A vault privy may be permitted by the Department and must include these features: 1) fly-tight
construction, 2) a superstructure affording complete privacy, 3) an earth mound around the top of the
vault and below floor level that slopes downward away from the superstructure base, 4) a floor and riser
of concrete or other impervious material, and 5) hinged seats and covers of easily cleanable, impervious
material. All venting must by fly-proofed with No. 16 or tighter mesh screening. Effective capacity of the
March 8, 2008 Page 34
vault privy must be no less than 400 gallons. Vaults for privies shall meet the same construction and
installation standards as septic tanks, except that they shall be single compartment and have no inlet or
outlet openings. Separate grey water systems will be required for treatment of grey water generated in a
building served by a vault privy. The vault privy shall be pumped by a licensed systems cleaner before the
waste level reaches 80 percent of the vault capacity.
D. Incineration Toilets
The Department may permit an incineration toilet designed and installed in accordance with all
applicable federal, state, and local air quality requirements. Incineration toilets must bear the seal of
approval of the NSF or an equivalent testing program. Incineration toilets shall be installed and operated
according to manufacturer's specifications. Separate grey water systems will be required for treatment of
grey water generated in a building served by incineration toilets.
E. Chemical Toilets
1. Use of a portable chemical toilet in permanently occupied buildings is prohibited, except during
construction or under emergency circumstances, as determined by the Department in its sole discretion.
2. An adequate number of chemical toilets must be provided and maintained at construction sites
and any other sites approved by the Department when other approved toilet facilities are not available.
3. Proper maintenance and cleaning of chemical toilets shall be the responsibility of the property
owner(s).
F. Composting Toilets
The Department may permit the use of composting toilets. Composting toilets must bear the seal of
approval of the NSF, or an equivalent testing program. Composting toilets must be operated according to
manufacturer's specifications and meet the following requirements:
1. Composting toilets may only be used for wastewater and readily decomposable household
garbage that is not diluted with water or other fluids. The volume of the toilet must be sufficient to
accommodate the number of persons served, according to the manufacturer's specifications.
2. Adequate additional volume shall be provided for the use of composting materials. Such materials
shall not be toxic to the process or hazardous to persons or the environment and shall be used in
sufficient quantity to assure proper decomposition.
3. Compartments and appurtenances related to the unit must include fly-tight construction and
exterior ventilation, as required by the International Plumbing Code.
4. When the available effective volume is filled to 75 percent of capacity, residue from the unit shall
be properly disposed of in accordance with state sludge regulations (5 CCR 1003-7) and solid waste
regulations (6 CCR 1007-2, Part 1), together with the federal standards for the use or disposal of sewage
sludge (40 CFR 503) and any other applicable federal, state or local rules and regulations in the
jurisdiction where disposal will occur.
5. If a system will be installed where low temperature may be a factor, the design must compensate
for the effects of the low temperature.
The Department may also require that systems utilizing composting toilets include plans for the treatment
of grey water.
March 8, 2008 Page 35
G. Cesspools
Cesspools are prohibited.
H. Hot Tubs and Therapeutic Bathing Facilities
Hot tubs and therapeutic or recreational bathing facilities shall not discharge to septic tanks or
absorption systems.
I. Water Softeners
Discharge from the brine recharge cycle of water softeners using sodium chloride in the brine solution
shall not be discharged to a septic tank or absorption system.
J. Floor Drains
Floor drains shall not discharge into septic tanks or absorption systems.
K. Business, Commercial, Industrial, Institutional, or Multi-Family Dwelling Waste Systems
1. Performance criteria and construction standards for an OWTS that will service commercial,
business, institutional or industrial property or multi-family dwellings (any dwelling consisting of four or
more units, such as a fourplex or larger, or four or more individual units on one system) must conform to
this Regulation.
2. Such systems shall be designed by a PE. These systems shall receive only such biodegradable
wastes for treatment and dispersal as are compatible with those biological treatment processes indicated
in the submitted design.
3. If anticipated wastes are other than domestic-type, an application for such system shall be
reviewed and approved by the CWOCD.
6.28.150 Licensing
A. General
1. Systems Contractors
a. Any entity or individual engaged in the construction, installation, alteration, or repair of an
OWTS in Pitkin County is required to be licensed by the Department as a licensed systems contractor.
b. No entity or individual shall construct, install, after, or repair an OWTS unless the work is
performed by a licensed systems contractor, or is being performed under the direct supervision of a
licensed systems contractor. Corporations and other entities operating as systems contractors in Pitkin
County must employ at least one person who is a licensed systems contractor.
c. A property owner may construct, install, alter, or repair an OWTS on such person's own
property without a license, provided that the property owner (or an authorized representative of the
property owner, in the case of an entity) receives the Department's approval by successfully
demonstrating adequate knowledge of this Regulation by passing a test administered by the Department
prior to construction, installation, alteration, or repair of the system.
March 8, 2008 Page 36
2. Systems Cleaners
a. Any entity or individual engaged in OWTS cleaning in Pitkin County is required to be licensed
by the Department.
b. No entity or individual shall engage in the cleaning of an OWTS unless the work is performed
by a licensed systems cleaner, or is being performed under the direct supervision of a licensed systems
cleaner. Corporations and other entities operating as systems cleaners in Pitkin County must employ at
least one person who is a licensed systems cleaner.
3. Systems Inspectors
a. Any entity or individual engaged in OWTS inspection in Pitkin County is required to be
licensed by the Department.
b. No entity or individual shall engage in the inspection of an OWTS unless the work is
performed by a licensed systems inspector, or is being performed under the direct supervision of a
licensed systems inspector. Corporations and other entities operating as systems inspectors in Pitkin
County must employ at least one person who is a licensed systems inspector.
B. Licensing Procedures for Systems Contractors, Cleaners, and Inspectors
1. Application for a systems contractor, cleaner, or inspector license, or license renewal, shall be
made on forms provided by the Department.
2. Fees for a systems contractor, cleaner, or inspector license and license renewal will be
established by the Department from time to time. Initial licenses and renewals thereof shall be for a period
of one year. A license that lapses because of failure to renew, or is revoked, shall be subject to the fee
established for an initial license upon reapplication.
3. Prior to the issuance of an initial license, license renewal, or reinstatement of a revoked license,
the applicant must demonstrate adequate knowledge of this Regulation by passing a test administered by
the Department, or provide documentary evidence that they hold a similar type of license acceptable to
the Department (e.g., NEHA's Certified Installer of Onsite Wastewater Treatment Systems, for systems
contractors and NAWT's Inspector credential, for systems inspectors). A test will be administered for: a)
all initial licenses, b) every three years for renewals (or earlier, if necessitated by a material change in this
Regulation), and c) prior to reinstatement of a revoked license.
4. The fee for testing (and retesting) of a property owner engaged in the construction, installation,
alteration, or repair of an OWTS on such person's own property shall be charged at the same rate as a
systems contractor initial license. Initial approval and subsequent approvals given by the Department to a
property owner shall be for a period of one year.
C. Standards of Performance
1. General
a. Construction, installation, alteration, repair, inspection, or cleaning of any OWTS shall be in
compliance with this Regulation and with the conditions set forth in the permit.
b. It is the responsibility of the systems contractor, cleaner, or inspector to report to the property
owner(s) and the Department, in writing, the discovery of any prohibited component of an OWTS (such as
a metal tank or cesspool), or a malfunctioning system.
March 8, 2008 Page 37
2. Additional Standards of Performance for Licensed Systems Contractors
The systems contractor shall be responsible for making arrangements for all inspections required
for final approval of an OWTS construction permit, unless the Department is notified and approves other
arrangements.
3. Additional Standards of Performance for Licensed Systems Cleaners
a. Systems cleaners, when cleaning a septic tank or other primary treatment unit, shall remove
the liquid, sludge and scum, leaving no more than 3 inches depth of wastewater in anon-backflowing
septic tank or other primary treatment unit. In backflowing types of systems, cleaning shall be effective in
reducing solids and scum to the point of a near-new system. A dosing or pumping chamber is not
required to be pumped unless accumulation of sludge or scum interferes with the proper operation of the
OWTS.
b. After pumping the septic tank or other primary treatment unit, a systems cleaner shall inspect
the tees, baffles, aerator unit, pumps, alarms, filters, siphons and other internal or external components of
the tank(s) being pumped and notify the property owner(s), in writing, if any of these components are
damaged or missing. Any filters, or other devices which require routine maintenance and cleaning shall
be inspected and cleaned by the systems cleaner, if necessary.
c. Systems cleaners shall maintain their equipment to ensure that no spillage of wastewater will
occur during transportation and so that their employees are not subjected to hazards. Systems cleaners
are strongly encouraged to have proper personal protective equipment and immunizations for protection
against diseases associated with wastewater.
d. Systems cleaners shall dispose of waste materials removed from any OWTS only at an
approved Domestic Wastewater Treatment Plant, as defined by CWQCC Regulation No. 22, or other site
approved by the CWQCD that is willing to accept the waste. Disposal must occur in a manner that does
not create a hazard to public health, a nuisance, or a risk of pollution.
4. Additional Standards of Performance for Licensed Systems Inspectors
It is the responsibility of the systems inspector to report to the property owner(s) and the
Department, in writing, the discovery of any prohibited component of an OWTS, encroachment into
setback distances specified in Section 6.28.040 of this Regulation, any evidence of a malfunctioning
system or component, an inadequately sized OWTS, or lack of adequate servicing of mechanical
equipment related to manufactured units. Systems inspectors shall be qualified to perform OWTS
inspections for all OWTS use permits and shall submit a written report of such inspections to the property
owner(s) and the Department.
D. Revocation of Licenses
1. A systems contractor, cleaner, or inspector license may be revoked for failure to comply with this
Regulation, or for other good cause shown. Written notice of the violation(s) and/or other reasons for
revocation of the license shall be delivered to the systems contractor, cleaner, or inspector by overnight
mail, delivery requested the next business day, to the address specified on the license. The systems
contractor, cleaner, or inspector shall have 10 business days after the date of delivery of the notice to
provide a written response to the Department. Revocation of a license shall take place only after a
hearing before the Board of Health. The systems contractor, cleaner, or inspector shall be given notice of
the hearing in the same manner specified above, and may be represented at the hearing by counsel.
2. Application for a new license for a systems contractor, cleaner, or inspector whose license has
been revoked shall not be considered for one year after revocation.
March 8, 2008 Page 38
6.28.160 Prohibitions on Permits
The Board of Health may conduct a public hearing (after written notice to all affected property owners,
as shown in the records of the Pitkin County Assessor and publication of notice in a newspaper of general
circulation at least 10 days prior to the hearing), to consider the prohibition of permits in areas that are
subdivided for a density of more than two buildings per acre. The Board of Health may order such
prohibition upon a finding that the construction and use of additional OWTSs in the defined area will
constitute a hazard to public health and/or the environment. In such a hearing, the Board of Health may
request that affected property owners submit engineering and geological reports concerning the defined
area and provide a study of the economic feasibility of constructing a wastewater treatment works.
6.28.170 Enforcement
A. Primary Enforcement Responsibility
The primary responsibility for enforcement of this Regulation shall lie with the Department, pursuant
to §25-10-110 C.R.S. If the Department substantially fails to administer and enforce the provisions of §25-
10-101 et. seq. C.R.S. and the rules adopted pursuant thereto, the CWOCD may assume such functions
of the Department as may be necessary to protect public health and water quality, as provided under the
provisions of §25-10-110 C.R.S.
B. Access to Site
1. The Department and its authorized representative(s) are authorized to enter upon private
property at reasonable times and upon reasonable notice to determine if an OWTS is functioning in
compliance with §25-10-101 et. seq. C.R.S., this Regulation, and the terms and conditions of any permit.
The Department and its authorized representative(s) are further authorized to enter upon private property
at reasonable times and upon reasonable notice to inspect and conduct tests for purposes of evaluating
any permit application. The owner(s) and occupant(s) of every property having an OWTS subject to a
permit, or a pending permit application, shall, by virtue of that permit or application, be deemed to have
granted the Department and its authorized representative(s) permission to access the property upon
which the OWTS is located to conduct required tests, take samples, monitor compliance, and make
inspections in accordance with this Regulation.
2. The Department, or a licensed systems inspector, shall inspect an existing OWTS at the request
of the property owner(s) or occupant(s) for purposes including, but not limited to property transactions to
determine the need for servicing, repair and appropriate upgrades. Inspections by the Department shall
be conducted following submittal of a written inspection request, subject to staff availability and following
payment of inspection fees to the Department.
C. Complaints Regarding Violations
Persons who be-ieve that an OWTS is in violation of the requirements of this Regulation shall report
the purported violation to the Department: The Department, in its discretion, may require the information
related to any complaint to be provided in writing. Upon receipt of a complaint, the Department shall
investigate the matter and, if appropriate, issue a notice of violation. The Department, in its discretion,
may also refer the matter immediately to the Pitkin County Attorney's Office and request that the notice of
violation be issued by the Pitkin County Code Enforcement Officer.
D. Notice of Violation; No Other Approvals or Permits to Be Issued
1. Whenever the Department determines that there has been a violation of any provision of this
Regulation, the Department (or the Pitkin County Attorney's Office, as specified above) shall give notice
of such violation to the owner(s) of the property. Such notice shall be in writing, and shall describe in
detail the violation(s), provide a reasonable time for correction, and be addressed to the owner(s) of the
March 8, 2008 Page 39
property at the owner's(s') last known address, as shown on the records of the Pitkin County Assessor's
Office. Service of such notice shall be provided according to the Colorado Rules of Civil Procedure, or by
overnight mail. Service by overnight mail shall be considered complete one business day after mailing. If
the owner(s) cannot be found or served after a diligent effort to do so, service may be made by posting a
notice in a location conspicuous on or about the property affected by the notice.
2. Each day during which any violation of this Regulation continues shall be deemed a separate
offense.
3. Pitkin County shall be entitled to suspend or revoke any building permit, or any other type of Pitkin
County permit or land use approval issued for a property where a violation is known or believed to exist
during the period of the violation. Additionally, no Pitkin County land use approval or permit shall be
issued for any property under the ownership or control of the same person(s) or other legal entity(ies)
responsible for the violation during the period of the violation.
E. Cease and Desist Order
1. The Department may issue an order to cease and desist from the use of any OWTS that is found
not to be in compliance with a permit issued by the Department, not functioning in compliance with this
Regulation, or that otherwise constitutes a nuisance or a hazard to public health or the environment, and
that has not received timely repairs in accordance with the provisions of this Regulation. A cease and
desist order may be issued only after a hearing that shall be conducted by the Health Officer (or by the
Chair of the Board of Health if the Health Officer is not available) not less than 48 hours after written
notice is given to the owner(s) of the property on which the OWTS is located and at which the owner(s)
may be present, with counsel, and be heard. Service of notice of the hearing shall be provided according
to the Colorado Rules of Civil Procedure, or by overnight mail to the owner's(s') last known address, as
shown on the records of the Pitkin County Assessor's Office. Service by overnight mail shall be
considered complete one business day after mailing. If the owner(s) cannot be found or served after a
diligent effort to do so, service may be made by posting a notice in a location conspicuous on or about the
property affected by the notice. The cease and desist order shall require that the owner(s) bring the
OWTS into compliance, or eliminate the nuisance or hazard within a reasonable period of time, not to
exceed 30 days, or thereafter cease and desist from the use of the OWTS.
2. A cease and desist order issued by the County shall be reviewable pursuant to §25-10-
106(1)(k)(I) C.R.S.
3. A hearing on a cease and desist order may also include the assessment of monetary penalties,
as specified in subparagraph F(2) below. Where the hearing is conducted by the Chair of the Board of
Health (where the Health Officer is not available), the Chair of the Board of Health shall also have the
right to assess monetary penalties, as described below.
F. Penalties
1. Any person who commits any of the following acts or violates any of the provisions of this
Regulation commits a Class 1 petty offense, as defined in §18-1.3-503 C.R.S:
a. Constructs, alters, installs, or permits the use of any OWTS without first having applied for
and received a permit as provided for in Sections 6.28.020 and 6.28.030 of this Regulation;
b. Constructs, alters, or installs an OWTS in a manner that involves a knowing and material
variation from the terms or specifications contained in the application or permit;
c. Violates the terms of a cease and desist order that has become final under the terms of
Section 6.28.170(E) of this Regulation;
March 8, 2008 Page 40
d. Conducts a business as a systems contractor or systems cleaner, without having obtained
the license provided for in Section 6.28.150 of this Regulation;
e. Falsifies or maintains improper record keeping concerning OWTS cleaning activities not
performed or performed improperly; or
f. Willfully fails to submit proof of proper maintenance and cleaning of an OWTS as required by
Section 6.28.130 of this Regulation.
It shall be the responsibility of the Pitkin County Attorney to bring a criminal enforcement action at the
request of the Board of Health, following a request for criminal enforcement by the Department. Criminal
enforcement shall be in addition to all other remedies specified in this Section 6.28.170.
2. Upon a finding by the Health Officer that a person is in violation of the provisions of this
Regulation, the Health Officer, upon request by the Department, may assess a monetary penalty for each
day of violation. Such penalty shall be not less than $25 per day, nor more than $100 per day. In
determining the amount of the penalty to be assessed, the Health Officer shall consider the seriousness
of the danger to the public health and the environment caused by the violation, the duration of the
violation, and whether the person has previously been determined to have committed a similar violation.
A penalty may be assessed only after a hearing that shall be conducted by the Health Officer after written
notice is given to the owner(s) of the property on which the OWTS is located and at which the owner(s)
may be present, with counsel, and be heard. Service of notice of the hearing shall be provided according
to the Colorado Rules of Civil Procedure, or by overnight mail to the owner's(s') last known address, as
shown on the records of the Pitkin County Assessor's Office. Service by overnight mail shall be
considered complete one business day after mailing. If the owner(s) cannot be found or served after a
diligent effort to do so, service may be made by posting a notice in a location conspicuous on or about the
property affected by the notice.
3. A person subject to assessment of a monetary penalty pursuant to subparagraph E(3) or
subparagraph F(2) above may appeal the decision to the Board of Health. No appeal shall be considered
unless a notice of appeal and brief written statement of the grounds for appeal is received by the
Department not later than 30 days after the decision is rendered. Within 15 business days after receipt of
a properly documented notice of appeal, the Department will schedule an appeal meeting (which shall be
a public meeting) before the Board of Health. To the degree possible, appeals will be scheduled for the
next regularly scheduled meeting of the Board of Health with an available time slot. At the meeting on the
appeal, the Board of Health shall review the record of decision and shall provide the property owner(s) an
opportunity to discuss the grounds for the appeal and the basis for the alleged error in the decision. The
Board of Health may also hear from any third party it deems appropriate. The Board of Health shall only
reverse, modify, or remand a decision on appeal if it finds that there has been a clear and demonstrable
error, abuse of discretion, or denial of procedural due process in the application of the facts in the record
to the standards of this Regulation.
G. Liens and Costs of Collection
Until paid, any monetary penalty assessed pursuant to this Regulation shall, as of recording with the
Pitkin County Clerk & Recorder, be a lien against the property on which the violation has been found to
exist. If the assessment is not paid within 30 days, it shall be certified by the Pitkin County Attorney to the
Pitkin County Assessor, who shall collect the assessment, together with a 10 percent penalty for the cost
of collection, in the same manner as other Pitkin County taxes are collected. The laws of the State of
Colorado for assessment and collection of general taxes shall apply to the collection of assessments
pursuant to this subparagraph (G).
March 8, 2008 Page 41
6.28.180 OWTS Zones
A. Designations
1. Two types of zones may be designated by the Pitkin County Board of County Commissioners in
order to protect public health and the environment: a) OWTS Protection Zones, and b) OWTS Public
Improvement Zones.
2. OWTS Protection Zones may be designated where surface water or groundwater quality may be
threatened in a discrete geographical or hydrologic area, requiring the discharges of pollutants to
groundwater to be systematically evaluated and specialty regulated (such as areas of high vulnerability to
contamination, as defined in the HSA/HHI study). In recommending designation of an OWTS Protection
Zone, the Department will consider risks to the public health and to vulnerable or sensitive water
resources, mass pollutant load discharges to the groundwater, proximity of OWTSs to surface waters, as
well as to wetlands and riparian areas, and the applicable Colorado stream classifications and standards.
OWTS Protection Zones may be required when one or more of the following risk factors are present: a)
areas with a high density of OWTSs (greater than two buildings per acre with an OWTS), b) aging
OWTSs and/or evidence of problematic undocumented OWTSs, c) areas in close proximity to
groundwater, a drinking water supply, water courses and/or steep slopes, d) areas where soils have poor
filtering capability, and/or v) areas with high groundwater.
3. OWTS Public Improvement Zones may be designated for areas where the need for adequate
long-term service and management of aerobic, mechanical, secondary or advanced secondary treatment
systems is considered necessary for maintaining public health and/or to protect vulnerable surface and
groundwater resources (such as areas of high vulnerability to contamination, as defined in the HSA/HHI
study).
B. Performance
1. OWTS Protection Zones shall ensure that OWTSs within the zone boundaries are installed,
operated and maintained in a manner that is protective of surface water and groundwater quality and
shall be established on asite-specific basis, accounting for the risks that lead to establishment of the
OWTS Protection Zone.
2. OWTS Public Improvement Zones shall ensure that OWTSs within the zone boundaries
consistently attain their expected and/or stipulated minimum performance criteria through proper
operation and maintenance. Expected and/or stipulated performance criteria shall be as defined in the
ANSI/NSF Standard 40 Class I standards. Administration and functions of the OWTS Public
Improvement Zone shalt follow management guidelines in the U.S. Environmental Protection Agency's
Voluntary National Guidelines for Management of Onsite and Clustered (Decentralized) Wastewater
Treatment Systems.
6.28.190 Definitions and Acronyms
A. Scope
1. Unless otherwise expressly stated, the words, terms, and acronyms used in this Regulation shall
have the meanings set forth in this section for the purposes of this Regulation. Where words, terms, and
acronyms are not defined in this section, such words, terms, and acronyms shall have ordinarily accepted
meanings, as implied by the context in which they are used.
2. All references to statutes, regulations and standards shall be deemed to refer to such statutes,
regulations and standards as amended from time to time.
March 8, 2008 Page 42
B. General Definitions and Acronyms
"AASHTO" means American Association of State Highway and Transportation Officials.
"Absorption area" means an area where effluent is treated through infiltration into the soil. The size of
the absorption area shall be calculated in accordance with the provisions of this Regulation.
"Absorption bed" means a subsurface soil absorption area that is wider than 3 feet and equipped with
a distribution system that distributes effluent to infiltrate into the soil.
"Absorption system" means a system for the treatment of effluent by means of absorption into the
soil.
"Absorption trench" means a subsurface soil absorption area no more than 3 feet in width, with at
least 6 feet of undisturbed soil between each trench, that distributes effluent to infiltrate into the soil.
"Access opening" means an opening of sufficient size to permit access to a septic tank or dosing or
pumping chamber.
"Adequate water supply" means a legal source of water that reliably meets the water quantity and
quality requirements necessary for the desired use and is sustainable. Minimum requirements for
adequate water supply vary depending on whether the water supply is from a private well, a surface water
diversion, or a public water system. In all cases, the water supply must meet the requirements of the
Pitkin County Land Use Code. Evidence of an adequate water supply shall include:
1. For private wells: the well driller's report, a well permit issued by the Colorado Division of Water
Resources for the desired use, and a judicially decreed augmentation plan or State Engineer approved
substitute water supply plan (if such a plan is required by the Colorado Division of Water Resources). If
water will be supplied from a shared private well, then an authorized representative of the entity
administering the well must also provide a letter confirming that it will provide water to the site for the
desired use and has an adequate water supply to do so. Determination of adequate water quality is the
responsibility of the property owner(s).
2. For public water systems: a letter from the water supplier confirming that it is a CWOCD-approved
public water system, will provide service to the site, and has an adequate water supply to do so. These
water supplies shall conform to the Primary Drinking Water Regulations.
3. For surface water diversions: proof of judicially decreed water rights (including a final
augmentation plan, if required) for the desired use.
"Advanced secondary treatment" means the extended secondary treatment of effluent for the purpose
of reducing levels of BOD, suspended solids, and total nitrogen prior to final dispersal to an absorption
area, or other means of treatment, as allowed by this Regulation. The minimum reduction of total
nitrogen in the effluent shall be 50% of influent total nitrogen.
"Aerobic wastewater treatment system" means an OWTS in which the mechanical addition of air
maintains the action of the system.
"ANSI/NSF Standard 40 unit" means a residential OWTS meeting Standard 40 of the American
National Standards Institute (ANSI) and the National Sanitation Foundation (NSF). ANSI/NSF Standard
40 contains minimum requirements for residential OWTSs having single defined discharge points and
average daily wastewater flows between 400 and 1,500 GPD. ANSI/NSF Standard 40 units are defined
as either Class 1 or Class 2 units. Class 1 units meet U.S. Environmental Protection Agency requirements
for secondary treatment. For purposes of this Regulation, an OWTS meeting ANSI/NSF Standard 40 for
March 8, 2008 Page 43
1,500 GPD shall also be considered as meeting the ANSI/NSF criteria for OWTSs with average daily
wastewater capacities greater than 1,500 GPD and less than 2,000 GPD.
"Applicant" means any person who submits an application for a permit.
"ASTM" means the American Society of Testing and Materials.
"Average daily wastewater flow" means the average amount of wastewater produced per day by a
dwelling or other establishment, as described in Section 6.28.050.
"Barn" means an agricultural building used to shelter or enclose livestock, horses, poultry, feed, or
field equipment, or where trees, shrubs, flowers, or vegetable plants are grown. An indoor riding arena is
not considered a "barn".
"Bedrock" means the consolidated or solid rock that underlies soil material, or is located at the earth's
surface.
"Bedroom" means a room suitable for sleeping that is greater than 70 square feet, with or without a
closet, with no dimension less than 7 feet, and that has access to a full or 3/< bath.
"Biomat" means a layer of biological growth and inorganic residue that develops at the wastewater-
soil interface.
"Board of Health" means the Pitkin County Board of County Commissioners convened for the specific
purpose of fulfilling the responsibilities of the Pitkin County Board of Health.
"BOD" means biological oxygen demand.
"BOD5" means the measured decrease in dissolved oxygen after five days of incubation as a result of
biological oxygen demand. BOD5 is a particular empirical test following specific standards and conducted
in a laboratory.
"Building" means any structure(s) designed or built for the support, enclosure, shelter, or protection of
persons, animals, or property of any kind.
"Caretaker dwelling unit" means an accessory dwelling unit attached to, or detached from, a principal
dwelling and situated on the same parcel.
"CDPS permit." See "Colorado Discharge Permit System permit."
"Cesspool" means a covered excavation in the ground receiving untreated wastewater or other
organic wastes from a drainage system that is designed to retain the organic matter and solids, permitting
the liquids to seep into the soil cavities.
"Chemical toilet" means acommode-type seat or bowl attached to a container holding a chemical
solution that changes the waste into sludge.
"Color" means the color of moist soil based on MunsellO soil color charts.
"Colorado Discharge Permit System permit" means a permit obtained from the CWQCD to discharge
wastewater, stormwater or other water to waters of the State.
"Colorado Water Quality Control Commission (CWQCC)" means the administrative agency
responsible for developing specific water quality policy in Colorado, in a manner that implements the
broader policies set forth by the Legislature in the Colorado Water Quality Control Act. The CWQCC
March 8, 2008 Page 44
adopts water quality classifications and standards for surface and ground waters of the state, as well as
various regulations aimed at achieving compliance with those classifications and standards.
"Colorado Water Quality Control Division (CWQCD)" means the division of the Colorado Department
of Public Health and Environment responsible for administering and enforcing regulations enacted by the
Colorado Water Quality Control Commission.
"Community water system" means a public water system that serves at least 15 service connections
used by year-round residents, or that regularly serves at least 25 year-round residents.
"Composting toilet" means aself-contained commode constructed to decompose non-water-carried
human waste through microbial action, producing a composted product.
"Constructed wetland" means a system that uses wetland plants to provide secondary treatment of
wastewater through biological, physical, and chemical processes.
"Department" means the Pitkin County Environmental Health and Natural Resources Department.
Wherever the term "Department" is used in this Regulation, it shall also be considered to include the
CWQCD for the purposes of administering and enforcing the provisions of this Regulation where
necessary to protect public health and the environment.
"Design flow" means 150 percent of the average daily wastewater flow.
"Detailed soil map" means a map prepared by the Natural Resources Conservation Service, or other
state or federal agency, showing soil series, types, and phases at a scale of not more than 2,000 feet to
the inch and which includes related explanatory information.
"Dispersal system" means a system for the dispersal of effluent after final treatment by a method that
does not depend upon or utilize the treatment capability of the soil.
"Distribution box" means a watertight chamber that receives effluent from a septic tank or other
primary treatment unit and that distributes effluent evenly throughout an absorption system.
"Distribution pipe" means the pipe used to deliver the effluent to the absorption area or filter area and
the pipe used to disperse effluent in the absorption area or filter area. The distribution pipe from the septic
tank or other primary treatment unit to the absorption area is solid wall. The distribution pipe in the
absorption or filter area is perforated.
"Distribution valve" means atwo-way valve, accessible from the surface, with one inlet and two or
more outlets where wastewater flow can be diverted into separate and different directions.
"Dosing or pumping chamber" means a chamber or a separate tank that stores effluent and
discharges it at a high rate to an absorption system through either a dosing siphon or a pump.
"Dosing system" means a chamber or separate tank that stores effluent and discharges it at a high
rate to an absorption system through either a dosing siphon or pump.
"Drop-box" means a structure to divert effluent into an absorption trench until the trench is filled to a
set level and then allows any additional effluent, which is not absorbed by that trench, to flow to the next
drop-box or absorption trench.
"Dry gulch" means a deep, V-shaped valley or ravine formed by erosion that contains a dry creek
bed.
March 8, 2008 Page 45
"Dry well" means a subsurface absorption system filled with gravel and designed on the basis of
sidewall and bottom absorption area.
"Dwelling" means a building, or portion of a building, that is used as the private residence or sleeping
place of one or more human beings.
"Effective size" means the soil grain size of the diameter for which only 10 percent of the particles are
finer.
"Effluent" means liquid discharged from a septic tank or other primary treatment unit.
"Effluent filter" means anon-corrodible screen that limits the size of solids that may leave a septic
tank or pumping chamber.
"Evapotranspiration/absorption (ETA) system" means an OWTS that utilizes a combination of an
evapotranspiration and absorption system.
"Evapotranspiration (ET) system" means a type of dispersal system that relies on liquid evaporation
and transpiration by vegetation.
"Filled area" means an area where naturally occurring soil conditions have been modified or filled in
by soils from another location.
"Floodplain" means an area adjacent to a watercourse that is subject to flooding as a result of the
occurrence of the "100-year flood." Where the 100-year floodplain has not been determined, "floodplain"
shall mean an area that is 5 vertical feet or 20 horizontal feet, whichever is greater, from the high water
line or the high water profile of the maximum flood of record, whichever method of computation is greater,
on any river, stream, or natural drainage channel.
"Floodway" means the area within the floodplain where the channel of the watercourse and those
portions of the adjoining floodplain must be kept free of fill and obstructions in order to discharge the
"100-year flood" without increasing the water surface elevation more than 1 foot at any point.
"Gallons per day (GPD)" means a unit of measure commonly used to describe the rate of flow into or
out of an OWTS.
"Geoexchange system" means a heat pump or heat exchange system having a horizontal or vertical
closed-loop portion consisting of pipe buried in trenches, boreholes, or wells (ground-source), or
submerged in a body of water (water-source), in which a heat exchange medium (fluid or vapor) is
circulated and fully contained within the pipe or tubing. The purpose of the closed loop is to provide for
the transfer of heat between the circulating fluid or vapor and the ground or water.
"Geothermal well" means a well that is constructed for the purpose of exploration, use of a
geothermal resource, or reinjection of a geothermal fluid. The term "geothermal well" does include loop
fields, but does not include a well subject to the provisions of Articles 90 and 92 of Title 37, C.R.S., wells
subject to the jurisdiction of the Oil and Gas Conservation Commission pursuant to Article 60 of Title 34,
C.R.S., or wells subject to the jurisdiction of the Mined Land Reclamation Board pursuant to Articles 32
and 33 of Title 34, C.R.S..
"Global positioning system (GPS) coordinates" means latitude and longitude coordinates obtained
from ahand-held receiving unit based on signals obtained from a satellite network. The receiver locates
four or more satellites to mark a location.
March 8, 2008 Page 46
"Gravelless chamber system" means a type of effluent distribution system in which the void space
and soil contact area, normally provided by a gravel matrix, is provided by a high density polyethylene
mold with interior storage capacity and an open bottom area.
"Grey water system" means a system that uses water drained from baths, showers, washing
machines, dishwashers and sinks, or other household wastewater, excluding toilets (black water). Grey
water contains bacteria and other potential pathogens, but also contains the nutrients nitrogen and
phosphorus.
"Health Officer" means the health officer appointed by the Board of Health pursuant to §25-1-610
C.R.S.
"High groundwater" means the soil saturation zone, including a perched water table, shallow regional
groundwater table or aquifer, or any zone that is seasonally, periodically, or permanently saturated.
"Holding tank" means an approved watertight receptacle for collecting and holding wastewater.
"Horizontal reference point" means a stationary, easily identifiable point to which horizontal
dimensions are related.
"HSA/HHI study" means the report entitled, Development of GIS-Based Ground Water Resources
Evaluation of the Upper and Middle Roaring Fork Valley Area, Pitkin County, Colorado, prepared by
Hydrologic Systems Analysis, LLC and Heath Hydrology, Inc., dated November 14, 2005, and all similar
Roaring Fork Watershed groundwater studies conducted by Hydrologic Systems Analysis, LLC and/or
Heath Hydrology, Inc. for Pitkin County.
"Incineration toilet" means aself-contained commode-type seat connected to a holding tank and a
gas-fired or electric heating system to incinerate waste products deposited in the holding tank.
"Invert" means the bottom of the interior of a pipe.
"Large capacity OWTS" means an OWTS with an average daily wastewater flow of 2,000 GPD or
more, which requires a permit from the CWQCD.
"Lined sand filter" means a single pass or recirculating sand filter providing secondary treatment in
which the filter media and collection piping are contained within an impervious liner and treated effluent is
discharged to an absorption area.
"Living area" means the heated, habitable floor area within the inside perimeter of the exterior walls of
a dwelling.
"Long-term acceptance rate (LTAR)" means the acceptance rate of a soil after the break-in period is
complete. The break-in period includes the development of a suitable level of biological activity. The
break-in period for a soil treatment component may also include the development of a hydraulically-
restricting biomat until the point of equilibrium is reached.
"Long-term resting" means 1 to 2 years of no discharge of effluent into the absorption area.
"Loop field" means any excavation or borehole constructed for the installation of piping to contain a
fluid or vapor for circulation in the operation of a closed-loop geoexchange system.
"Malfunctioning system" means an OWTS that is not functioning in compliance with the requirements
of this Regulation and the design of the system and includes:
1. Systems that seep or flow to the surface of the ground, or into waters of the State;
March 8, 2008 Page 47
2. Systems that have overflow from any of their components;
3. Systems that cause backflow into any portion of a building plumbing system due to failure to
operate in accordance with their designed operation;
4. Systems discharging effluent that do not comply with applicable effluent discharge standards; and
5. Systems that fail to operate in accordance with manufacturer specifications.
"Manifold" means that portion of solid wall distribution pipe having several outlets through which the
effluent is equally distributed to several branches of distribution pipe.
"Manufactured unit" means an aerobic wastewater treatment system, a secondary treatment system,
or an advanced secondary treatment system.
"Minutes per inch (MPI)" means a unit of measure typically used to describe soil percolation rate.
"Mound system" means an absorption system in which the top of the effluent distribution pipe is
installed above the original grade of the absorption area. A mound system is typically used in areas
where groundwater or bedrock is close to the ground surface.
"NAWT" means the National Association of Wastewater Transporters.
"NEHA" means the National Environmental Health Association.
"New technology system" means a system based on improvements and developments in the
technology of wastewater dispersal not otherwise provided for in the Colorado Revised Statutes.
"Non-community water system" means a public water system that is not a community water system. A
"non-community water system" is either a "transient, non-community water system" or a "non-transient,
non-community water system," as such terms are defined in the Colorado Primary Drinking Water
Regulations.
"NOWRA" means the National Onsite Wastewater Recycling Association.
"Nuisance" means public nuisance as known in common law or equity jurisprudence; whatever is
dangerous to life or detrimental to health; whatever building is not sufficiently ventilated, sewered,
drained, cleaned, or lighted, with respect to its intended use; and whatever renders the air, food, drink, or
a water supply unwholesome.
"Observation pipes" means pipes installed in an OWTS for purposes of observing water levels.
"Onsite wastewater treatment system (OWTS)" means a system for collecting, treating, and
dispersing wastewater that is not connected to a central wastewater treatment works.
"Package plant" means a manufactured aerobic wastewater treatment system serving multiple
buildings or an educational, health care, or other large facility.
"Percolation test" means a subsurface soil test to determine the water absorption capability of the soil.
The results of percolation tests are given as the number of minutes it takes 1 inch of water to be
absorbed, or MPI. Larger values correspond to slower percolation rates, while lower values correspond to
faster percolation rates (e.g., 60 MPI is slower than 5 MPI).
"Permeability" means the ease with which liquids move through the soil. It is one of the soil qualities
listed in soil survey reports.
March 8, 2008 Page 48
"Permit" means a document issued by the Department authorizing the construction, alteration,
installation, repair, or use of an OWTS.
"Pounds per square inch (psi)" means a unit of measure commonly used to describe a compressive
force.
"Pressure dosing system" means a pressurized piping system which provides uniform dispersal of
effluent to the entire absorption system.
"Primary Drinking Water Regulations" means 5 CCR 1003-1.
"Primary treatment" means initial treatment of wastewater to remove floating and suspended solids
through natural biological processes that decompose wastes over time in a storage unit such as a septic
tank. Typical BOD concentrations following primary treatment are 150 mg/L.
"Private water system" means a water supply for human consumption that has less than 15 service
connections or regularly serves an average of less than 25 individuals daily at least 60 days out of the
year.
"Privy" means a structure that is not connected to a plumbing system and that is used by persons for
the deposition of human excreta, which provides privacy and shelter and prevents access to the excreta
by flies and rodents.
"Professional Engineer (PE)" means an engineer licensed in the State of Colorado in accordance with
§12-25-114 C.R.S.
"Public water system" means a water supply for human consumption provided through a system of
pipes or other constructed conveyances, if such system has at least 15 service connections or regularly
serves an average of at least 25 individuals daily at least 60 days out of the year. A "public water system"
is either a "community water system" or a "non-community water system." The Primary Drinking Water
Regulations require that public water systems meet drinking water quality criteria and require monitoring
for microbial contaminants, certain organic and inorganic chemical contaminants, radionuclides (for
community water systems only), and certain unregulated contaminants. Public water systems must be
approved by the CWQCD and may be privately owned.
"PVC" means polyvinyl chloride.
"Qualified geologist" means a person who is a graduate of an institution of higher education that is
accredited by a regional or national accrediting agency, with a minimum of 30 semester (45 quarter)
hours of undergraduate or graduate work in the field of geology and whose post-baccalaureate training
has been in the field of geology with a specific record of an additional 5 years of geological experience,
which may include up to 2 years of graduate work.
"Regulation" means the Pitkin County OWTS Regulation.
"Replacement area" means a reserved area on a parcel of land upon which no permanent structure
may be constructed and which is intended for replacement of an OWTS should it fail.
"Riparian area" means a vegetated area adjacent to and affected by a water body, having one or both
of the following characteristics: 1) distinctly different vegetative species relative to adjacent areas, and 2)
species similar to adjacent areas, but exhibiting more vigorous or robust growth forms. Riparian areas are
often transitional between wetland and upland areas.
"Sand filter" means a subsurface absorption system that contains an intermediate layer of sand as
treatment material.
March 8, 2008 Page 49
"Secondary treatment" means the treatment of effluent for the purpose of reducing BOD and total
suspended solids concentrations to levels that meet U.S. Environmental Protection Agency secondary
treatment guideline parameters. The 30-day average BOD5 concentration of the effluent sample shall not
exceed 25 mg/L and the 7-day average BOD5 shall not exceed 40 mg/L. The 30-day average of total
suspended solids shall not exceed 30 mg/L and the 7-day average shall not exceed 45 mg/L. The pH
shall be between 6.0 and 9.0.
"Separation fabric" means a geotextile material intended to serve as a separating layer between
dissimilar soils and reduce or prevent migration of soil particles.
"Septic tank" means a watertight, accessible, covered receptacle designed and constructed to receive
wastewater from a building sewer in order to settle solids from the liquid, digest organic matter, store
digested solids through a period of retention, and allow the clarified liquids to discharge to other treatment
units.
"Serial distribution system" means an arrangement of absorption trenches or beds that retain effluent
in one component to use the absorption capacity of that component before flowing into a succeeding
component.
"Setback" means the minimum distance between an OWTS component and a specified physical
feature, such as a riparian area, stream, lake, spring, wetland, dry gulch, drinking water source or
pipeline, property line, or other feature.
"Sewage." See "wastewater."
"Sewer" means piping that conveys liquid waste from a building or other structure to an OWTS.
"Soil mottles" means spots, streaks, or contrasting soil colors usually caused by soil saturation.
"Soil profile" means a description of the series of different horizons within the soil as determined by a
soil core. Horizons shall be differentiated on the basis of color, texture, soil mottles, or bedrock and
described in terms of thickness and depth measured from the ground surface.
"Soil profile hole or boring" means an observation hole dug for the purpose of obtaining an intact soil
core for use in documenting the soil profile. The profile may be either: 1) a test pit excavated with a
backhoe, or 2) a boring drilled with a minimum 4-inch auger.
"Soil saturation" means the condition in which pores in a soil are filled with water. Water will flow from
saturated soil into a soil profile hole or boring.
"Steep slopes" means slopes greater than 15 percent.
"Subsurface drip system" means a shallow absorption system using a pump or automatic siphon and
smaller diameter distribution piping with small-diameter perforations to discharge effluent to the soil.
"Suitable soil" means a soil that will act as a treatment media in removal of organisms and suspended
solids prior to the effluent reaching groundwater or any highly permeable earth, such as joints in bedrock,
gravel, or very coarse soils.
"System." See "onsite wastewater treatment system."
"Systems cleaner" means an entity or individual engaged in the cleaning and pumping of OWTSs.
"Systems contractor" means an entity or individual engaged in constructing, installing, altering, and/or
repairing OWTSs.
March 8, 2008 Page 50
"Systems inspector" means an entity or individual engaged in inspection of OWTSs.
"Total Maximum Daily Load (TMDL)" means the maximum quantity of a specified pollutant that can
be discharged to a stream and still allow the stream to attain water quality standards assigned to the
stream segment by the Colorado Water Quality Control Commission. TMDLs must be developed for
streams listed on Colorado's 303(d) list in accordance with the federal Clean Water Act.
"Treatment cell" means a single unit of a treatment process.
"Underdrain" means a subsurface drain below filter media used in a sand filter.
"Uniformity coefficient" means the coefficient that describes the size distribution of a soil and is equal
to Dso/D,o, where Dso is the diameter for which 60 percent of the particles are finer, and D,o is the
diameter for which 10 percent of the particles are finer. A uniformity coefficient of 4 is considered uniform.
A well-graded soil has a uniformity coefficient greater than 10.
"USDA NRCS" means the United States Department of Agriculture Natural Resources Conservation
Service.
"Vault" means a watertight, covered receptacle, designed to receive and store excreta or wastes
either from a sewer or from a privy and is accessible for the periodic removal of its contents.
"Vault privy" means a shelter built above a vault in the ground into which human waste is excreted.
"Waste material" means sludge from septic tanks or other treatment tanks, solids collected on filters
or in septic tanks, and construction materials or equipment that have been in contact with effluent and are
being removed.
"Wastewater" means a combination of liquid wastes that may include chemicals, household wastes,
human excreta, animal excreta, other animal or vegetable matter in suspension or solution, and other
solids in suspension or solution, and that is discharged from any building, dwelling, or other
establishment.
"Wastewater pond" means a pond designed to receive effluent from a septic tank or other primary
treatment unit and to provide an additional degree of treatment to the effluent.
"Wastewater treatment works" means a facility for treating, neutralizing, stabilizing, and dispersing of
wastewater that has a designed capacity to receive more than 2,000 GPD of wastewater. This term
includes appurtenances such as interceptors, collection lines, effluent lines, outlet sewers, pumping
stations, and related equipment.
"Waters of the State" means any and all surface and subsurface waters that are contained in or flow
in or through Colorado, except waters in sewerage systems, waters in wastewater treatment works,
waters in potable water distribution systems, and all waters withdrawn for use, until all uses and treatment
have been completed.
"Wetland" means areas that are inundated or saturated by surface or groundwater at a frequency and
duration sufficient to support, and that under normal circumstances do support, a prevalence of
vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps,
marshes, bogs, and similar areas.
March 8, 2008 Page 51