Loading...
HomeMy WebLinkAboutpitkin.eh.264929102033 (1996).ASPEN/PITKIN ENVIRONMENTAL HEALTH DEPARTMENT ' I��V0fe. APPLICA FOR INDIVIDUAL SEWAGE DISPOSAL SEM ' 130 S. Galena St., Aspen Colorado 81611 �q Phone 970-92(00-5070/f=ax 9/700-920-5039 Perrc,it :/ C'W�� Parcel ID # l l — �� Permit For: New Installation ( ) Repair ( ) Remodel ( ) Emergency Use ( ) NQ,f A:3 J k_,, _ `cD a r Name of OWNER �1,g , /,r�rio,JVIA el.� /� p Owner's Mailing Address C> ! 3 dam_ Business Phone: 1(e 3 — Q G, �, % Home Phone: cj �„ 3 — O `% Name of Agent Agent's Mailing Address Business Phone : Cell Phone: Fax Copy of permit to be sent to: Owner ( Agent( ) Both ( ) Street Address Legal Description: Lot —H Block _ Subdivisiont- ✓; Size of lot: . S'2- acres Type of proposed structure: _ Size of bldg. envelope: ,/j� Total area/living space (sq. ft): InV ,I' �r� `Of Bedrooms, offices and similar size :rooms: # of similar size rooms: Water:( )Private well( )Spring ( )Stream ( ) Community/Public (Name of System) Is Proof of Adequate Water Attached ? ( ) Yes ( ) No Has this project been approved by Pitkin County ? ( ) Yes ( ) No Is a copy of the floor plan attached ( required ) ? ( ) Yes ( ) No Application for an individual sewage disposal system is hereby submitted. The undersigned acknowledges that the above information is true and that false information will invalidate the application and any subsequent permit. Issuance of the permit does not imply the approval of any other permit required for construction pursuant to Pitkin County codes. No construction may be undertaken until all approvals and permits have been obtained. The owner assumes all responsibilities in case of failure or inadequacy of this system. ,� q Signature of applicant —� . ' " \� Date -7-2- — 5 For department use below Septic tank, capacity: PERMIT FOR INDIVIDUAL SEWAGE DISPOSAL SYSTEM gallons Absorption area: sq. ft. —th cYe. 1-5 f s n nJ 15 n /5 5 a.Le bt./ t 'd e c� altwwfc„L ax� i�^a too C An inspection is required prior to backfill of any component of the distribution system. Design by Engineer Required '? ( ) Yes (,, No All plans and specifications of the engineer must be followed. Any changes must be approved in writing and the engineer must certify the final installation to the Environmental Health Department in writing. Permit approval by: ,-JJJ w1„ (4 J%y c /L- Date Plans and specifications of the proposed individ I ewage dis I system have been reviewed and are considered satisfactory. Perrot sion is hereby granteli to the owner or the agent to perform the work indicated in accordance with the Pitkin County ISDS Regulation in effect at the time of issue. This permit becomes invalid 6 months from the date that the permit was issued unless system construction has commenced or an extension has been approved in writing by the Department. Installer. h l As -Built drawings must be included ' t s permit before the final approval will be issued. �� � Final Inspection Approval: �. ��Q ii _ r Date: 1 Q Date requested: C1 tom., _ Date Pd.: - ( �} Cv Receipt #: 0"'3-(08- Received by: � C G� Information complete: � (y �e�-� ► (� �v�-�t� (-,e Ctttkc E..Qr�C �I-a 44- o, -tL_ 4--t-L NJ, U ax) , cqx low M �, w ��'�_ C��► 0 tq l a Sa ox., -ra4tit Geo cvetf too a 0&a -_t "ae E a ✓n.e�'�-en U-�iA .���d �et.�rac� Ll,�ia.�.r. �L�� 1�y be Z�ea-4z 10 �- �i�y fl i$n / Sx lS• /�twr.� v� d2 /ia 5 c3z l�sa-r)atirnt a.-Cn . U Gto � e -,wtloltlA� veaupo(-9�6&�, be re,,�?4 6--x �,V/4 Jiv. k t a a ___ � � 3Y� 141-�.c�`C�►�i, pc-'VIC d ry,\tj6k of �e-. ,nom i ��o concrete © C� eek. -i-0�-✓1 k W i a- p Geonnw►' blQ . 1 riser Hr,�- Ar , fc�v ayt's , 0',O-ta-p- Ovd vek, 1 C3 -Pt Fxe- '479-1 6- 't4-� z Ick- k n t� r Q A �a'a aQ-r� � resey In Td=m r,ecf ti t"D lk\ "t r t of alo v-tc . Printed on Recycled Paper ASPEN/PITKIN ENVIRONMENTAL HEALTH DEPARTMENT ISDS DESIGN REQUIREMENTS DEPARTMENT USE ONLY .Permit # Name Shannon Meckley Parcel ID # 2649-291-02-033 House Size 1969 sq. ft. (75 gpd, 100 gpd, or 130 gpd) 75 Number of Bedrooms, Lofts, Offices, Similar Rooms, Main House 3 Number of Bedrooms, Lofts, Offices, Similar Rooms., Caretaker unit 0 Average Daily Waste Flow 450 (# bedrooms X 2 people/br X 75) State Review Required? no Perc•Rate 43 (T) Design Flo w (Q) _ # bedrooms X 2 people/bedroom X gpd X 1.75 Q= 787.5 Absorption Area (A= Q/5 X SART) A = 1032.797 sq. ft. of absorption area required 1.5 JS 57 infiltrator units without reduction A maximum 30% reduction is allowed for use of deep gravel or gravelless chambered system. 722.9576 sq:ft. with reduction CICO 40 infiltrator units with reduction a aGJ. l.IJ6 Type of system: []Absorption trenches []Absorption bed:[] Gravelless chambers []Dry well []Seepage Pit []Pumping Chamber Is an Engineer -Designed System required? no yes — reason: Minimum tank capacity 1250 gallons SETBACK FROM WELL # of feet = 100 Remember: 8 feet of additional distance for each 100 gallons/day of design flow. over 1,000 gallons/day should be added unless an RPE can verify that Jt is not necessary to prevent cotamination. APPROVED FOR ISSUE BY: DATE: SYSTEM INSTALLED BY: DATE OF FINAL INSPECTION REQUEST: FINAL INSPECTION BY: DATE: Printed on Recycled Paper ° ^` ,� Aspen / Pitkin Environmental Health Department -- n September 5, 1996 Shannon Meckley 0138 Apache Trail Carbondale, CO 81623 Re: Sewage Disposal System at 0138 Apache Trail Dear Mr. Meckley: C] ASPEN • PITKIN ENVIRONMENTAL HEALTH DEPARTMENT I have received an application and payment for the installation of a new sewage disposal system to be installed at 0138 Apache Trail due to the failure of the existing system. I have also received the perc test, soil data and the floor plan of your existing home as well as the floor plan of a proposed addition. I have calculated the size of a new drywell based on the size of the home, the perc rate and the number of bedrooms and rooms that must be counted as bedrooms. The size of a drywell needed for a 4 bedroom home with a living area between 2,000 - 6,000 sq. ft. and a perc rate of 43 minutes per inch is 1,836 sq. ft. This would typically be accomplished by a 20 foot square by 20 feet deep drywell. This situation is somewhat complicated by the fact that there is an unpermitted 15 foot square by 15 feet deep pit that is already filled with gravel. There is no 4 inch perforated pipe present in this pit. In order to be able to use the unpermitted pit as a drywell, the requirements in the Pitkin County Individual Sewage Disposal System Re_ ulatic)nn will have to be met. These requirements include at least one four -inch perforated vertical stand pipe must be attached to the end of the distribution line with a tee fitting. It must go to the bottom of the drywell and up to the finished grade and be fitted with a removable cap to be used as an inspection pipe. The gravel must extend to at least two inches above the inlet pipe. Since a 15 foot square by 15 foot deep drywell only amounts to 1,125 sq. ft. of absorption area, an additional 12 foot square by 12 ft. deep drywell will be required, adding 720 sq. ft. of absorption area. The two added will give 1,845 sq. ft. total of absorption area. The two drywells must be separated by a distance equal to the depth of the excavation or ten feet, whichever is greater. In this case, they would have to be at least 15 feet apart. Another option would be to use one drywell that is 15 ft. deep, but is 23 ft. square. This would provide 1,90,9 sq. ft. of absorption area. Again, all of the installation requirements of the regulation would have to be met. It is important that all setback requirements be met regardless of the system design. These include a 20 ft. setback from occupied dwellings, 10 ft. setback from the property line, 25 ft. setback from drinking water supply lines. There must be 5 ft. between the septic tank and dwelling and 6 ft. between the tank and the drywells. I believe your subdivision is on its own water system, but if you or any of your neighbors are on a well, the setback is 132 ft. I don't recall any lakes, water 130 SOUTH GALENA STREET • ASPEN, COLORADO 81611 • PHONE 303.920.5070 • FAx 303.920.5197 P..« ­­y&d Fap, courses, irrigation ditch0or streams, but the setback Ahese would be 82 ft.. If there are any dry gulches the setback is 57 ft. 1 have included a setback chart to help clarify any of these figures. The Pitkin County Individual Sewage Disposal System Regulation requires that the Environmental Health Department issue a notice of violation whenever we learn of a sewage disposal system failure. This letter serves as a notice of violation. The new system should be completed by September 16, 1996. Once this department has inspected the installation and given final approval, the new system should be the only one in use. If this deadline cannot be met, please contact me as I will gladly work with you to extend the deadline for good cause. This failed system is considered an immediate health threat and must be remedied as quickly as possible. If there is failure to comply, a cease and desist order will be issued. Please don't hesitate to contact me if you have questions. Sincerely, Mary Engelmann Aspen/Pitkin Environmental Health Officer cc: John Ely, Pitkin County Attorney SENDER: fl ■ Complete items 1 and/or 2 for additional services. rn ■ Complete items 3, 4a, and 4b. ■ Print your name and address on the reverse of this form so that we can return this card to you. -Attach this form to the front of the mailpiece, or on the back if space does not permit. d ■Write'Return Receipt Requested' on the mailpiece below the article number. M ■The Return Receipt will show to whom the article was delivered and the date c delivered. O m 3. Article Addressed to: CL E /LO -/7 n6r?, Pe Ck W c (� �✓ bcy Z Cr 5. Received By: (Print Nam6 W Cr g 6. ftRatute-( ddressee or O X H PS Form 11, December 1994 b60 N,-23 I also wish to receive the following services (for an extra fee): 1. ❑ Addressee's Address 2. ❑ Restricted Delivery Consult postmaster for fee. 4a. Article Number P �57loa lel (__ 4b. Service Type ❑ Registered Certified ❑ Express Mail �� ❑ Insured ❑ Return ReAjp&rltll2TLTfaa6b ❑ COD 7. Date of rpt-`�J 8. and fee etu rn I UNITED STATES POSTAL SERVICE First -Class Mail Postage & Fees Paid USPS Permit No. G-10 • Print your name, address, and ZIP Code in this box • fi 4 t f -k t Y1 iE7 hv. -eaJ1 13 S. C i -e00- of JUN -16-1996 04.26 P.02 ' HN'Pwowrli-PAWLAK GEOTECIRNYCAL, INC. 5020 Road 154 Glenwood Springs,, CO $1601 August 23, 1996 Fax 970 945-x454 Phone 970 94.54M Shannon Mekley 0138 Apache Drive Carbondale, Colorado 81623 Job No. 196 378 Subject: Percolation Testing, Lot 11, Swiss Village Subdivision, Pitkin County, Colorado Dear Mr. Mekley: As requested, a representative of Hepworth-Pawlak Geotechnical, Inc. conducted percolation testing at the subject site. The findings of our work are presented in this report. The work was done in accordance with our agreement for geotechnical engineerilig services to you, dated July 26, 1996. Lot 11 is occupied by an existing two story wood frame single family residence. Vegetation at the site consists of scrub oak trees with grasses and weeds. The ground surface slopes moderately down to the east. Seepage was observed from the existing leach field embankment. We understand the existing leach field will be replaced with a seepage bed. A profile boring was drilled on August 1, 1996 approximately 33 feet cast of the southeast corner of the existing residence. The proposed seepage bed had been excavated( 10 feet south of the profile boring. The excavation was cut to 18 feet below the adjacent grades and had been partially filled with 1'h" screened rock. The subsoils encountered to the profile boring consisted of 4 feet of silty sand and gravel fill overlying silty sand and gravel with scattered cobbles and boulders to the maximum depth explored of 22 feet. The soils were slightly moist to moist. The results of a gradation analysis performed on a sample of natural silty gravelly sand (minus 1'h inch fraction) taken from the boring are presented on Fig. 1. No free water was observed in the boring. Percolation Test holes were excavated on August 20 1996 with a backhoe. Hand dug holes approximately 12 inches deep and 8 inches in diameter were dug in the bottom of the pits and pre-soaked on August 20, 1996 by the owner. On August 21, 1996, we conducted percolation testing. The percolation test results are summarized on Table I. If there are any questions or if we may be of further assistance, please let us know. Sincerely, HEPWO'RTH - PAWLAK G HNICAL, INC. Louts E. Eller Reviewed By: �1l51l111i .'.ifliJ+ �y�vr 0 REG 'r4 e 's Daniel E. Hardin P.E. 2 �$3 0 AUG 2 71996 SS. % ���?% Y .� •off?,•. o•+�v�".� _ LEE/kw°ee�ee�NeaN, ENVIRONMENTAL HEALTH attachmentf�rii„S'SIQNAL Ev`\�� GRADATION TEST RESULTS JUN -16-1996 04:2? HEPWORTH-PAWLAK GEOTECHNICAL„ INC. TABLE I PERCOLATION TEST RESULTS P.04 JOB NO. 196 378 it V V 4 1 1750 l Oki3 Jo�� C� o TOTAL P.04 WATER DEPTH AT END OF INTERVAL (INCHES) DROP IN WATER LEVEL (INCHES) AVERAGE PERCOLATION RATE (MINJINCH) HOLE DEPTH (INCHES) LENGTH OF INTERVAL (MIN) WATER DEPTH AT START OF INTERVAL (INCHES) FFHOLE 41 15 water added 83/4 73/4 1 60 73/4 71/2 1/4 7 112 7 1/2 7 63/4 1/4 63/4 61/2 1/4 7 6112 1 /2 81/2 6 114 1/4 2 66 15 93/4 83/4 1 120 83/4 81/2 1/4 $112 8114 1/4 8114 81/4 0 9114 B 1/4 8 8 0 8 73/4 1/4 3 60 15 water added water added 71/2 61/2 1 20 6 112 53/4 3/4 71/2 63/4 3/4 63/4 61/4 112 61/4 51/2 314 7 61/4 3/4 it V V 4 1 1750 l Oki3 Jo�� C� o TOTAL P.04 JLH-16-1996 0426 P.01 HepworthPawlak G�q eotech TEL:303-945-8454 4T-1 .. 1•• 1. Aug 29 96 15:55 No.005 P.01 3 � Q j ASPEN • PITKIN ENVIRONMENTAL HEALTH DEPARTMENT " 13 . �p .173 3g 10 4 zs ,Ts 314 -7.-7-5 (� 1 (5 �- q� �. 3 ( 0) 920-5070 l� 130 THGALENASTREET ASP , COLORADO 81611 0 ASPEN • PITKIN Al ENVIRONMENTAL HEALTH DEPARTMENT z - r4L�-; 75/1 1�0 ell ire C> 42 (970) 920-5070 ..{ i 130 SOUTH GALENA STREET Q r - I v PEN,COLORADHZ6ZZ �?) . 40 - PERCOLATION TEST SHEET - Test hole location Hole # `7 Date test hole was prepared: Depth of hole bottom: \� �j p u� inches Diameter of hole: ! inches Soil Data from test hole: depth, inches soil texture: soil color Method of scratching sidewall: Depth of pea size gravel in bottom of hole: inches Date and hour of initial water filling: Depth of initial water filling above hole bottom Method used to maintain 12" of water depth in hole for 4 hours: Percolation test conducted by; Percolation test started at (am / pm). Maximum water depth above hole bottom during test:__ inches Ten Percent Calculation * R,B,C INTERVAL WATER WATER WATER R PERC RATE x 0.10 = TIME (MINUTES) DEPTH (fi'DRtO n) aciTART (d mal) CALCULATION t arg¢st omall¢st 0.10 = �q TIME DROP PERC -'-��-�--- 20 Y'--�---- ---------- CDecimal) REFILL' 'Y_ T B -___-_- • VOG ---_ _ TIME DROP PERC -_--- (Decimal) • REFILL "' "Y' � C ___ _ _ -- ---------- TIME DROP (Decimal) PERC ID REFILL , 4 2- _ 'TIME _ DROP PERC -------- -Ip- (Decimal) E F I L� \ 7 Decimal �� REFILL _ 4' �'1" _ i•! i��------ TIME DROP PER,-- - --[---� -_ _ (Decimal) G REFILL _ 1� ` _ _ DRO PRC PP -RC -------- -_� - ----E (Decimal) REFILL t r0_ ---------- ------ _-_- TIME DROP PERC of ('a (Decimal) Ten Percent Calculation * R,B,C oma ¢st o = arg¢st o x 0.10 = est C,0,E # o _ t arg¢st omall¢st 0.10 = E,F,G ma ¢s[ o x 0.10 = 1B, C' x 0.10 = ma est o ®,E,F arg¢sc # o mall¢st # o E.F x 0.10 = ma11¢st o F,G,H arg¢st o mal ¢tet r„a est o x 0.10 = __ conversions 1/16 =.06 1/8 =.13 3/16 =.19 1/4=.25 5/16 =.31 3/8 =.38 7116 =.44 1/2=.5 9/16 =.56 5/8 =.63 11/16 =.69 3/4 =35 13/16 = .81 7/8 =.98 15116 =.94 ' If the top number in each set of boxes is larger than the bottom number then take another reading. If the top number is equal or smaller than bottom number, average the three numbers for the perc rate. • gam'/ 116 3/1 a , -7 fi a y `� - PERCOLATION TEST SHEET - Test hole location Hole #f - I Date test hole was prepared: Depth of hole bottom: j i' inches Diameter of hole: 5 4f_ inches Soil Data from test hole: depth, inches soil texture: soil color Method of scratching sidewall: �C�iC3�t�t L,�$/7G/Depth of pea size gravel in bottom of hole: inches Date and hour of initial water filling:�/:/ a_yYI Depth of initial water filling; above hole bottom Method used to maintain 14" of water depth in hole for 4 hours: Percolation test conducted by; Percolation test started ate. to ef=j pm). Maximum water depth above hole bottom during test: inches urg¢st N o rr•a eat o x 0.10- I .10 - cat o IC,D,E rr•allest o S_ x 0.10 - a ¢st o E,F,G s7­11ent 4V o ma est o x 0.10 - Ten Percent Calculation * Ful ,c,D argcat o ma cat o S -11—t o x O_10 s rD,E,F argcat o1>1EVmallest # o X 0.10 = F,G,H argcat o ma est o t trta est x O_10 = conversions 1116 -z.05 118z.13 3116 =.19 114 =.25 5116 =.31 318 =.38 7116 =.44 1/2=.5 9/16 =.56 5/8 =.63 11/16 =.69 314 = .75 13/16 =.81 7/8 =.88 15116 =.94 ' If the top number in each set of boxes is larger than, the bottom number then take another reading. If the top number is equal or smaller than bottom nu;i oor, avorage the three numbers for the perc rate. INTERVAL WATER WATER DROP WATER FERC RATE TIME (MINUTES) DEPTH( (decimal) CALCULATION START_r �t TIME DKOP PERC _f_'9 __63- ---�- fs %.4t ---------- ---------- (Decimal) R E F I L L 6-3 - yb B ' 1'CC TIME DROP PERC ------- _ -_ '---- (Decimal) REFILi r'__f�4t_ C W_ TIME DROP PERC (0 `_ « REFILL• _ — D `i D TIME RO-P PERC ------ --1----_4� ---------- ---- ---------- REFILL �: __�__ Z _ REFILL C• oc1/itp _ TIMEDROP ---------- -------- -- PERC ( ecimal) _ F �! REFILL Q. /�_ �_"_• _ .` �' - �_+_I,% __ TIME DROP PERC --------'���_ ---------- ---------- (Decimal) REFILL DROP s PERC ---TIME --------- - ----- ---------- (Decimal) Y� REFILL _ // _ H -------- _ XoO TIME DROP PERC - ---------- (]Decimal) urg¢st N o rr•a eat o x 0.10- I .10 - cat o IC,D,E rr•allest o S_ x 0.10 - a ¢st o E,F,G s7­11ent 4V o ma est o x 0.10 - Ten Percent Calculation * Ful ,c,D argcat o ma cat o S -11—t o x O_10 s rD,E,F argcat o1>1EVmallest # o X 0.10 = F,G,H argcat o ma est o t trta est x O_10 = conversions 1116 -z.05 118z.13 3116 =.19 114 =.25 5116 =.31 318 =.38 7116 =.44 1/2=.5 9/16 =.56 5/8 =.63 11/16 =.69 314 = .75 13/16 =.81 7/8 =.88 15116 =.94 ' If the top number in each set of boxes is larger than, the bottom number then take another reading. If the top number is equal or smaller than bottom nu;i oor, avorage the three numbers for the perc rate. - PERCOLATION TEST SHEET - Test hole location & 6F .S ITI Hole 0 —1 Date test hole wasprepared: !O Z -I- Q�' � -y It Depth of hole bottom: I inches Diameter of hole: ! inches Soil Data from test hole: depth, inches soil texture: soil color 0-:711 LOAM (in Y2Z 7-tS L -014M A96kid C icy& Method of scratching sidewall:-&CgR,b V/ b%4L3 Depth of pea size gravel in bottom of hole inches Date and hour of initial water filling: (0-2* )0-Ov /4#1Depth of initial water filling:` 2• /r above hole bottom Method used to maintain 12" of water depth in hole for 4 hours: Aurora. 7yc— Percolation test conducted by; ._) e5E J D H NSO U Percolation test started at 6 , zJ 0/ pm). Maximum water depth above hole bottom during test: ZS inches -6:00 TIME INTERVAL (MINUTES) WATER DEPTH WATER DROP (fraction) WATER DROP (decimal) PERC RATE CALCULATION IX/x/ V M �I: START 3Q-- 1 to -�C-- la=-C►-�- �I� 0 — 1-x+1 =�. TIME DROP PERC A ?IiD __1_ _ 1_�, gL REFILL It 2�1B TIME DROP PERC I► ' REFILL 30__ c �� . ► .� r_ � D TIMH ' �DR(DP p , zit 7-L---7 F ,O REFILL n �/j 1 �_/4 t• �S --�`=-F-- - -'f- - -t--- --- PERC (Decimal) •� REFILL r. � (• -- .(._ �7 �f Ei TI E DROP PERC -_---- ---------- Decimal REFILL -------- - TIME DROP PERC (Decimal) REFILL CT ---------- - _ TIME DROP a PERC (Decimal) REFILL H -------- -------- ---------- ---- - TIME DROP PERC (Decimal) 17 —11—It 4Vo C,D,E x 0.10 = 1-7 Ten Percent Calculation * z- zz = i eat -f = srnmjl—t o 2-7- O.1 O - E,F,G ma ext4Vo x 0.10 - B,C,2D3 — arg�st o $ZiS ma eat' o D,E,F argent 0 o —Ii—t o x 0.10 = ma est o F,G,H argot o ma eat o I ma eat o i x 0.10 = conversions 1116 =.06 1/8=.13 3116 =.19 114 =.25 5116 =.31 3/8 = .38 7/16 =.44 112 =.5 9/16 =.56 5/8 =.63 11/16 =.69 314 =35 13/16 =.81 7/8 =.88 15//16 =.94 - It the top-surnh(,r it each set of boxes is larger than the bottom number then take another reading. If the top number is vgjal or smaller than bottom number, average the three numbers for the perc rate. Successful design of an on-site sewage treatment system depends on an adequate site evaluation The percolation test is only one small part of a complete site evaluation. Refer to Locating On -Site Home Sewage Treatment Systems, FO -0797, for the complete site evaluation procedure. Suitable soil is the keyto providing adequate on-site sewage treatment. Soil which is too coarse will not do a good job of moving nutrients and bacteria. Loam or clay loam soil will do an excellent j ob of nutrient and bacteriaremoval but will require a relatively large soil treatment area. Seasonal saturation of a soil will cause sewage to backup if the trenches are constructed too deep. 1. Use soil borings to locate a suitable area. Soil borings should be at least 3 inches in diameter and at least 3 feet deeper than the bottom of the proposed soil treatment system. A boring may stop as soon as evidence of seasonal soil saturation or bedrock is encountered. Number the soil boring holes and locate them on a scale map of the site. Evaluate the soil texture (sand, loamy sand, sandy loam, loam, silt loam, clay loam, etc.) for every foot of depth or at least where achange in soil texture occurs (see Figure 2). Record this data onalog sheet ofthe boring hole. Ifyou encounter seasonally saturated soil or an impervious layer (rock or clay) at a depth of 3 feet or closer to the ground surface, the area is not suitable for a subsurface soil treatment unit. A sewage treatment mound, however, could be installed at such a location if other factors such as slope were suitable. If saturated soil or arestricting layer is encountered between 3 and 4.5 feet, you can add fill over the Figure 2. A hand -operated bucket auger collects a relatively undis- turbed sample, allowing proper evaluation of soil texture and obser- vance of possible mottling. 2 • entire site to bring the final ground surface elevation to at least 4.5 feet above the restricting layer. Seasonal saturation of soil is indicated by a gray back- ground color together with red streaks or splotches and is called mottling. The bottom of the drainfield trench should be located no closer than 3 feet from the mottled soil. Even though the hole may be dry when you make the soil boring, the soil will be saturated during wet conditions and during the operation of the sewage treatment system. The system will fail in clay soil or inadequately treat sewage in coarse soil. The lawn area required for the soil treatment unit depends on the percolation rate of the soil and the amount of sewage discharged by the proposed or existing residence. Refer to your local sanitary code for required setbacks from buildings, prop- erty lines, water supply wells, etc. Take at least four soil borings in each soil texture in order to locate lawn area of adequate size. 2. Make an adequate numberof percolation test holes. If the soil texture is uniform over the selected site, use at least two and preferably three percolation test holes. If the soil texture changes withinthe site, make at leasttwopercolationtest holes in each soil texture. Space the percolation test holes uniformly over the area proposed for the soil treatment unit. 3. Dig test holes. The test holes should be round and at least 6 inches, but no larger than 8 inches, in diameter. Dig each test hole as deep as you intend to excavate the soil treatment trench. The bottom of the percolation test hole must be at least 3 feet above the level of seasonally saturated soil or an impervious layer. A clam shell - type posthole digger can be used (see Figure 3). If you use a 6 - inch auger, it is a good idea to drill a pilot hole with the 3 -inch auger. Observe and record the soil texture as the percolation test hole is being dug. 4. Prepare the percolation test holes. The auger orposthole diggeris likelyto smearthe soil along the sidewalls of the test hole. Therefore, the bottom 12 inches of the sidewalls and the bottom of the hole should be scratched or scarified with a sharp, pointed instrument such as a knife. Nails drivenintoa 1 x2 -inch board as shownin F1gure4 willdo agood job of scarifying the hole to provide an open, natural soil into which water may percolate. Remove all loose soil material from the bottom of the test hole. Add 2 inches of one-fourth to three- fourths inch gravel to protect the bottom from scouring when water is added. The gravel can be contained in a nylon mesh bag as shown in Figure 5 in order to be removed after the test is performed and used for additional percolation tests. 5. Distinguish between soil saturation and soil swelling. Saturation means that the voids between soil particles are full of water. This can happen in a short time. Cover: An adequate site evaluation is essential to the successful design of an on-site sewage treatment system. The percometer shown is a convenient device for measuring the percolation rate. Inset: A stop watch measures the drop in water level. L Swelling is caused by intrusion of water into individual soil particles. This is a slow process, especially in clay soils, and is why a prolonged soaking period is necessary for some soils. Carefully fill the percolation test hole with clear water to a depth of at least 12 inches above the soil bottom ofthe test hole. Use a hose to prevent the water from washing downthe sides of the hole or add the water directly into the percometer as shown in Figure 7. A 6 -inch diameter hole requires about 1.5 gallons per foot of depth. Sandy soil containing no clay does not swell. The percola- tion test may proceed immediately ifthe 12 inches ofwater seeps away in 10 minutes or less. The percolation test procedure for sandy soils is described under step 6C. Forprolonged soil soaking, keep the 12 -inch depth of water in the hole for at least four hours, and preferably overnight. Add water as necessary. You may use an automatic siphon or valve to maintain the 12 -inch water depth (Figure 6). A valve made from the carburetor of a small engine is shown in Figure 8. 6. Measure percolation rate. Except for sandy soils, make the percolation rate measure- ments the day after completing step 5. A. If there is more than 6 inches of water in the hole after the overnight swelling period, bail out enough water so that 6 inches of water remains above the gravel (8 inches if measured from the bottom ofthe hole). Measure the drop in Figure 3. Either a post -hole auger or a clam shell digger can be used to dig the percolation test holes. Figure 4. The percolation test hole can be scarified with a knife or nails driven into a 1 " x 2 " board. Figure 5. If the gravel which protects the hole bottom from scouring is contained in a nylon mesh bag, it can be removed and reused. tj Figure 6. Water level device for percolation test hole. WATER LEVEL DEVICE FOR PERCOLATION TEST HOLE PLASTIC TUBING OR HOSE SUPPORT PLASTIC TUBING LATH FROM SUPPLY - WATER NEEDLE ALVE SUPPLY -S B SEAT WATER FLOAT CARBURETOR 1 WATER ` OUTLET ,. 12 INCH WATER WATER LEVEL DEPTH ABOVE BOTTOM OF HOLE L_ I 4 2 INCH DEPTH OF n TO 30 F �•'B�; INCH GRAVEL Figure 8. A small engine carburetor attached to a support controls the siphon and maintains a constant water level in the test hole. Figure 7. Cutting the top of the percometer tube at Figure 9. The liquid level in a percolation test hole can be observed directly at the top of the rod attached to the float. This is the most con- venient way to observe the drop in water level. the water level to the nearest 1/8 inch (preferably the nearest 1/16 inch) approximately every 30 minutes (Figure 9). If possible, use apercometerto determine the change in water level (Figure 10). A batter board can also be used as a reference point together with a hook gauge to accurately locate the water surface. The hook can be made from stiff wire or an 8d nail. After each measurement, refill the water 4 in the hole so that the liquid depth is 6 inches above the gravel. Continue taking measurements until three consecu- tive percolation rates vary by a range of no more than 10 percent (see sample field notes, page 7). B. If no water remains in the hole after the overnight swelling period, add 6 inches of clear water above the gravel. Measure the drop in the liquid level to the nearest 1/8 inch an angle allows for the convenient addition of water. Figure 10. Construction and use of a percometer. PFRCOMFTFR USE 3/3z BRASS OR CADMIUM PLATED BOLTS TO FASTEN GUIDES a STOPPER /B' DRILLED HOLES j (BOTH SIDES a IN PLASTIC PIPE) t /q /a' DRILLED HOLE DIA, PLASTIC PIPE 5' LONG ;E RIGID PERFORATED DRAIN 'E WITH 6 ROWS OF 3 -'/2" RFORATIONS IN BOTTOM FOOT) USE A RULER WITH DIVISIONS FOR MEASUREMENTS STIFF WIRE PERCOMETER 3 LATHS 24" LONG 3 PEGS OR NAILS 6" HOLE DIA. IS SUGGESTED (preferably 1/16 inch) approximately every 30 minutes. After each measurement, refill the water to a depth of 6 inches above the gravel. Continue the water level drop measurements until three consecutive percolation rates vary by no more than 10 percent. C. In sandy soils, or other soils in which the first 6 inches of water seep away in less than 30 minutes after the overnight swelling period, allow about 10 minutes between measure- ments. On some very sandy soils, use a stop watch and measure the time in seconds for the water level to drop from 6 to 5 inches (Figure 11). Refill the percolation test hole after each measurement to bring waterto 6 inches above the gravel. Continue taking readings until three consecutive percolation rates vary by no more than 10 percent. 7. Calculate percolation rate. Divide the time interval by the drop in water level to determine the percolation rate in minutes per inch (MPI). Examples: A. If the drop in water level is 5/8 inch in 30 minutes, the per- colation rate is 30 _ 30x 8 = 48 MPI or 30 _ 30 = 48 MPI 58 5 % 0.625 B. If the drop is 2 Y inches in 10 minutes, then the percola- tion rate is 2" TO 3" DIA. BY 4" TO 7" LONG PLASTIC BOTTLE OR EXPANDED POLYSTYRENE FLOAT 0 8" WATER DEPTH AT START OF READING (MEASURED FROM BOTTOM OF HOLE) L 2" OF GRA ' _L 10 _ 10 _ 10x = 4 MPI or 10 _ 10 = 4 MPI 2Y � 5 2Y 2.5 Figure 11. The percolation rate is determined by measur- ing the rate of water drop over time. For sandy soils a stop watch can be used to measure the drop in water level from six to five inches. W Table 1. Sewage flows and soil treatment areas ,Type I: The total floor area of the residence divided by the number of bedrooms is more than 800 sq. ft. per bedroom, or more than two of the following water -use appliances are installed—automatic washer, dishwasher, water softener, garbage disposal, or self-cleaning humidi- fier in furnace. Type 11: The total floor area of the residence divided by the number of bedrooms is more than 500 sq. ft. per bedroom, and no more than two of the water -use appliances are installed. Type III: The total floor area of residence divided by the number of bedrooms is less than 500 sq. ft. per bedroom, and no more than two of the water -use appliances are installed. Type IV: No toilet wastes flow into sewage treatment system. Calculate the percolation rate for each reading (see sample fieldnotes). Whenthreeconsecutivepercolationrates vary byno more than 10 percent, use the average value of these readings to determine the percolation rate for the test hole. Percolati on rates determined for each test hole should be averaged in order to determine the design percolation rate. For reporting the perco- lation rate, worksheets showing all measurements and calcula- tions should be submitted with the site evaluation report. You can reproduce the blank form on the back page of this folder for use in recording percolation test data. Note that a percolation test should not be run where frost exists in the soil below the depth of the proposed sewage treatment system. 8. Determine the trench bottom area. Table 1 shows sewage flows and soil treatment areas. The amount of trench bottom area required depends on the porosity of the soil as measured by the percolation rate, the daily sewage flow, and the depth of rock placed below the distribution pipe. Ttv daily amount of sewage wastes must be estimated in order to size the soil treatment unit. For residences; the daily amount of sewage flow is based onthe number of bedrooms and the type of residence. A luxury, three-bedroom house likely will generate more sewage than amore modesthouse. Sewage flows for different types of houses can be estimated from Table 1. Using a large sewage flow provides a factor of safety in sizing the soil treatment unit. Also consider future house expansion. Table 2. Soil treatment areas in square feet Percolation rate, minutes per inch Estimated sewage flows in gallons per da Type of residence, Number sewage treatmentb 0.1 to 5 0.83 6 to 15 1.27 of bedrooms I II II IV 2 300 225 180 60% of 3 450 300 218 values 4 600 375 256 in 5 750 450 294 Type I, 6 900 525 332 11, or 7 1050 600 370 III 8 1200 675 408 columns ,Type I: The total floor area of the residence divided by the number of bedrooms is more than 800 sq. ft. per bedroom, or more than two of the following water -use appliances are installed—automatic washer, dishwasher, water softener, garbage disposal, or self-cleaning humidi- fier in furnace. Type 11: The total floor area of the residence divided by the number of bedrooms is more than 500 sq. ft. per bedroom, and no more than two of the water -use appliances are installed. Type III: The total floor area of residence divided by the number of bedrooms is less than 500 sq. ft. per bedroom, and no more than two of the water -use appliances are installed. Type IV: No toilet wastes flow into sewage treatment system. Calculate the percolation rate for each reading (see sample fieldnotes). Whenthreeconsecutivepercolationrates vary byno more than 10 percent, use the average value of these readings to determine the percolation rate for the test hole. Percolati on rates determined for each test hole should be averaged in order to determine the design percolation rate. For reporting the perco- lation rate, worksheets showing all measurements and calcula- tions should be submitted with the site evaluation report. You can reproduce the blank form on the back page of this folder for use in recording percolation test data. Note that a percolation test should not be run where frost exists in the soil below the depth of the proposed sewage treatment system. 8. Determine the trench bottom area. Table 1 shows sewage flows and soil treatment areas. The amount of trench bottom area required depends on the porosity of the soil as measured by the percolation rate, the daily sewage flow, and the depth of rock placed below the distribution pipe. Ttv daily amount of sewage wastes must be estimated in order to size the soil treatment unit. For residences; the daily amount of sewage flow is based onthe number of bedrooms and the type of residence. A luxury, three-bedroom house likely will generate more sewage than amore modesthouse. Sewage flows for different types of houses can be estimated from Table 1. Using a large sewage flow provides a factor of safety in sizing the soil treatment unit. Also consider future house expansion. Table 2. Soil treatment areas in square feet Percolation rate, minutes per inch Soil treatment area in square feet per gallon of waste per day' Soil too coarse for Faster than 0.1b sewage treatmentb 0.1 to 5 0.83 6 to 15 1.27 16-30 1.67 31-45 2.00 46 to 60 2.20 Refer to information Slower than 60b on mounds 'For trenches only, the bottom areas maybe reduced if more than 6 inches of rock is placed below the distribution pipe; for 12 inches of rock below the distribution pipe the bottom areas can be reduced by 20 percent; a 34 percent reduction for 18 inches; and a 40 percent reduction for 24 inches. "Soil is unsuitable for standard soil treatment units. Refer to information on mounds and alternative systems. To illustrate the use of Table 1, determine the amount of trench bottom area required for a three-bedroom, type I dwell- ing. The soil percolation rate, as measured by the percolation data presented on page 7, is 27.3 MPI. From Table 1, a three- bedroom, type I dwelling is estimated to generate 450 gallons of sewage per day. The trench bottom area required for a percola- tion rate in the range of 16 to 30 is 1.67 square feet per gallon of waste per day. Thus, the total required bottom area is 1.67 X 450 = 750 square feet for trenches with 6 inches of rock below the distribution pipe. If 12 inches of rock is used as recommended, the trench bottom area can be reduced by 20 percent (see footnote a, Table 2). The required trench bottom area is then 0.80 X 750 = 600 square feet. The trench bottom area can be reduced by 34 percent for 18 inches of rock below the distribution pipe and by 40 percent for the maximum rock depth of 24 inches. As rock depth increases the required trench bottom area decreases, because more soil is exposed along the trench sidewall and a greater liquid depth increases the flow through the trench bottom. The minimum trench width is 18 inches; the maximum width is 36 inches. Using 36 -inch wide trenches in the above example, total trench length with 12 inches of rock below the distributionpipe is 200 lineal feet (600 = 3). No single trench can be longer than 100 feet. Thus, the 200 lineal feet should be divided into two or more trenches. The sewage effluent should be distributed between the trenches by means of drop boxes. Proper trench construction and drop box operation are explained fully in Town and Country Sewage Treatme% BU -1360. David Gustafson is Extension Specialist and Roger Machmeier is Professor Emeritus, Department of Agricultural Engineering, Minnesota Extension Service, University of Minnesota. Produced by the Educational Development System, Minnesota Extension Service. Copyright m 1993 by Minnesota Extension Service, University of Minnesota. The University, including the Minnesota Extension Service, is an equal opportunity educator and employer. Printed on recycled paper using 10% postconsumer waste. 6 ® \ I `� yY a0 ti `� a0 ti I v 0 t OA C- S,6 cY) 4 I ? XV a.goc�c� L: