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HomeMy WebLinkAboutpitkin.eh.264320406016 (1991)ASPEN#01TK.iil a �W3 2(70 ENVIRONMENTAL KAEALTH �EPAR'..,A ENT .2-3/0 -sa is t r /,• C2 INDIVIDUAL SEWAGE DISPOSAL PERMIT NO. TYPE OF PERMIT: XInitial Construction ( )Emergency Use ( )Repair Work,(Pievious Permit 1 .) ( )Alteration of an existing system, or Installation (previous Permit 1 ) ( )Use Permit as a result of Sale ( )Others ISSUED TO: DATE OF ISSUE Owner_ 0 A Home Phone 326 Business Phone cl2s--9 3/ % Mailing�- Address, -5-00 Agent Phone i Ma il;Lng Address Sewage Disposal System Work to be performed by This permit valid only for premises location by the fjoL�lowing e�gal d/encripti>oins u�C' / f L/N(� -L- ,/CwR CglC.t7S- LOT SIZE_ tr . WATER SUPPLY!/ j/ l°I L�EL�//D��Y,GiIi't'IC.II�VERACE PERCOLATTIION RATF. 0!"✓I/� This Individual Sewage Dis sal Permit is granted with regard to the following user SINCI C//711 L S f1- Nutaber oft Dodreoms LoftsGarbage Disposals_ DishwashersClothes/�Wa/shore CALCULATED AVERAGE DAILY BASTE LOAD `CALLONS��(1f"T/� ir��I L� MC/ r/ v� THE NATURE OF THE SYSTEM INCLUDED UNDER THIS PERMIT: spa of Tank or Treatment pits`<<" �A Tank. Capacity _Callon Minimum _shod of Final Disposals j EE EQ U �9 N Absorptiop .Area jj square Feet^miinnimmum _:crlption (including brand name, if any) of other equipment or appurtnaneest c� �1ft /iv'S �.9 c, �ED ,ther Conditions or Specificat nstAu PAL-, c q-rloN XAW i AJG S 0 � - AW�5c09D&J 08 �l a PA 1-670 -71 140S -r C taAN Fs l�ru r EuAml ( STAGES REQUIRING INSPECTION BY THE HEALTH DEPARTMENT: ( )Before Excavation I( )Upon completion of excavation and prior to placement of gravelBefore covering distribution system�of ablsorpti�]on field/ Prior to backfill of afiy component Mother, specifys Pla�nd s ecificattons of the ro sed sewage disposal system have been reviewed and are considered satisfactory. Permission P P Po 9 P Y I,, hereby granted to the owner or his aacnt to perform the work indicated above in accordance with the Pitkin County Indivi3ual Sewa;c Disposal Revulations in effect on the date of issue. In addition to general provisions set forth or, the reverse her_oi, this Permit is sutject to the following additional terms andd conditions; S Aspen/Pitkin Environmental APPROVED FOR I y/ - Health officerSUE BY (title) _— Tho ah ivc in:iividual sevago disposal syntcm Installed by hds been in:jpcctecl for use byl, a representative Cf the 113l:cn Pitkin Lnvlronrttinta re:;ponsibilIty in cese of failure or inadequacy of /th/io ewage ispoaal System. DATE OI Y.I. INSP CT O / / 120 q BY: M I. Health Dcpartmcnt. Tho uwnur as',c+P— aaa Complete ax -built drawing attachod. Aspen/Pitkin Environmental Health Officer TITLE 130 South (Galena Street Aspen, Colorado 81611 303/820-5070 v t • T ' ASPEN40PITKIN VoENVIRONMENTAL HEALTH DEPARTMENT APPLICATION FOR AN INDIVIDUAL SEWAGE DISPOSAL•PERMIT Name of OWNER vf- PHONE Address of OWNEF 5 G U L'' ) "c— // Name of APPLICANT � �t m � PHONE _ Z q20 ^ .3 (<N PERMIT TO BE: ( )Picked Up . kfMailed to* . TYPE of PERMIT: ,�Ioew Installation ( )Repair ( )owner ( )Applicant ( )Emergency Use ( )Alteration NOT due to failure LOCATION OF PROPOSED SYSTEM: Legal Description� Lot t Block_ rYPE*OF STRUCTURE: Subdivision b;pix(ASize of Lot acres Family Dwelling ( )Others Do you plan any further additions to the residence? ( )YES ( )NO No. of bedroomsr No, of Lofts No. of Garbage Disposals No: of Automatic Dishwashers No. of Automatic Clothes washers `lobi /�'( �tb WATER SUPPLYs ( )Private Well, Depthc, Name of System ��(!.S�f �/�-E�A� ( )Spring ( )Stream or Creek TYPES OF INDIVIDUAL SEWAGE DISPOSAL SYSTEM PROPOSED: (Septic Tank/Absorption Field ( )Aeration Plant/Absorption Field ( )Composting Toilet ( )Incineration Toilet ( )!bund (')Recycling, potable use ( )Recycling, other use ( )Vault Privy ( )Others The initial site inspection must be arranged with the Aspen/Pitkin'Environmental Health Department (925-2020, 8:30-9:30 a.m.) before a permit can be issued. The individual sewage disposal permit must be issued before a building permit can be obtained. FINAL INSPECTION APPROVAL MUST 1'jE GIVEN�If THE ASPEN/PITKIN ENVIRONMENTAL HEALTH DEPARTMENT PRIOR TO BACKFILLING ANY PORTION of THE SYSTEM. / 1 ,Rpplication for an individual Is true and that false _i t signature of Appli9d t NOTE: Please locate Miii is hereby submitted. The undersigned acknowledges that the above information e application and any subsequent permit. /7" J DATE q C� (This application becomes. invalid 12 months from the above date.) mush be filed with this application. following items by measured distances: 1. Property lines and dimensions. 2. Proposed and existing water wells on subject property and adjacent property. 3. Domestic water service lines., 4. Proposed and existing buildings, driveways, and other structures. S. Streams, lakes, ponds, irrigation ditches, and other water courses. 6. Proposed and existing individual sewage systems on subject property. , SUBMIT A REVISED PLOT PLAN PRIOR TO CONSTRUCTION IF INSTALLATION IS TO BE CHANGED FROM ORIGINAL PLAN. - The undersi ned h�;�by acknowledges receipt of> this individual sewage disposal permit application and a permit fee in the amount of = J _, Receipt Number t` ;, , Date Fee Received �T ��� w.by fice- x;T i trativo Ofr 130 South Galena Street Aspen, Colorado 81611 303/980-6070 .� �-� . �_� 0 .. ,, �` �� r � � � .f ,�'" � -�'_ � �� 73 m �M J_ SCHMUESER GORDO MEYER, AC. 1001 Grand Ave. Suite 2Z P.O. Box 2155 Glenwood Springs, CO 81601 Aspen, CO 81612 (303) 945-1004 i (303) 925-6727 TO DATE C, JOB 10.9' 1 7) ATTENTION RE: > WE ARE SENDING YOU Attached ❑ Under separate cover via ,X:I Shop drawing) ❑ Prints F-1PlansElSamples ElCopy of lette ❑ Change order ❑ the foliowing items: ❑ Specifications COPIES DAT NO. DESCRIPTION ZC11101cu "Ttr�_ .E5 1 THESE ARE TRANSMITTED as checked below: /lDFor approval ❑ Approved as submitted ❑ For your use ❑ Approved as noted ❑ As requested!' ❑ Returned for corrections ❑ For review and comment ❑ _ ❑ FOR BIDS D�E 19 REMARKS COPY PRODUCT 2403 � Inc., Groton, Masi 01471. ❑ Resubmit copies for approval ❑ Submit copies for distribution ❑ Return corrected prints ❑ PRINTS RETURNED AFTER LOAN TO US SIGNED:_ It enclosures are not as noted, kindly notify us at once. W i r • ASPEN+PITKIN ENVIRONMENTAL HEALTH DEPARTMENT Legal description: - Address of Property: Name of Owner: Address: PEST 7 (# & st. / p.o. box) Name of Agent: (city) (state) (zip) Lot Area:z�—Water Supply:Public Utility Subdivision_V'Apt/w� Private WO -11 Other Distance to Nearest Surface Water Type Dates Observations Made: Soil Borings: by Percolation Tests: by SOIL.BORING TESTS PERCOLATION TESTS Total Observed Depth Estimated Depth Character -Depth to Groundwater to Groundwater of Soils B-1 Depth of Water (left after 8 hr. presoak) I ,� ,( 2 (� PERCOLATION TESTS Rate P-1 �/ Rate P-2 90Rate P-3-57 AVERAGE RATE: '/o minutes/inch Plan of the site and location of test holes on to Comments on Soil or Site:. DateAIV Signature RIVdo—", 130 South Galena Street Aspen, Colorado 81611 303/920-5070 P-1 P-2 P-3 Depth Diameter ` Depth of Water (left after 8 hr. presoak) I ,� ,( 2 (� Rate P-1 �/ Rate P-2 90Rate P-3-57 AVERAGE RATE: '/o minutes/inch Plan of the site and location of test holes on to Comments on Soil or Site:. DateAIV Signature RIVdo—", 130 South Galena Street Aspen, Colorado 81611 303/920-5070 IDI€i� C7ill! Rate P-1 �/ Rate P-2 90Rate P-3-57 AVERAGE RATE: '/o minutes/inch Plan of the site and location of test holes on to Comments on Soil or Site:. DateAIV Signature RIVdo—", 130 South Galena Street Aspen, Colorado 81611 303/920-5070 P'j OF -3 SCHMUESER GORDON MEYER INC. 001 Grand Avenue, Suite 2-E Glenwood Springs, Colorado 81601 (303) 945-1004 (303) 925-6727 Fax (303) 945-5948 CONSULTING ENGINEERS & SURVEYORS August 29, 1991 Mr. Bob Nelson Pitkin County Environmental Health Department 130 South Galena Aspen, CO 81611 RE: Tiege ISDS - Brush Creek Village Pitkin County, Colorado Dear Bob: I am writing this letter to inform you that we have been retained by Ms. Joan Tiege to perform engineering services related to the design of her septic system for her proposed residence in Brush Creek Village. My understanding of the information, at present, is that either a sand filter (mound) type ISDS or an evapotranspiration (absorption) system would be the most likely alternatives for an ISDS for this site. I will be meeting with the client on Friday to evaluate the site and subsoil conditions. We anticipate (performing the scope of work within the next two weeks. You should receive a stamped set of drawings sometime during the week of September 9, 1991. 1 understand that you have] performed a percolation test for this site. I will be calling to discuss your observations of the site as well as to obtain percolation rates. If you have any questions, please do not hesitate to call. Sincerely, SCHMUESER GORDON MEYER, INC. f rey S. 4 JSS:Iec/99E Simonson, P.E. ti ChenONortherri, tic. A member of group of companies ® Consulting Engineers and Scientists SUBSOIL STUDY FOR FIOUNDATION DESIGN PROPOSED RESIDENCE LOT 7, BLOCK 7 BRUSH CREEK VILLAGE PITKIN COUNTY, COLORADO JOB NO. 4 251 91 MAY 23, 1991 PREPARED FOR JOAN TEIGE 500 EAST QOOPER ASPEN CD 81611-1834 q2O --32 V t (H q 2-7S- -131.7 (LY-). 5080 Road 154 Glenwood Springs, Colorado 81601 303 945-7458 303 945-2363 Facsimile CONCLUSIONS 1 PURPOSE AND SCOPE OF STUDY 1 PROPOSED CONSTRUCTION 2 SITE CONDITIONS 2 FIELD EXPLORATION 3 SUBSOIL CONDITIONS 4 FOUNDATION RECaMMENDATIONS 5 FOUNDATION AND RETAINING WALSS 6 FLOOR SLABS 8 UNDERERAIN SYSTEM 9 SITE GRADING 10 SURFACE DRAINAGE 11 LIMITATIONS 12 FIGURE 1 - LOCATION OF EXPLORATORY BORINGS FIGURE 2 - LOGS OF EXPLORATORY BORINGS FIGURE 3 - LEGEND AND NoffES FIGURE 4 - SWELL, -CONSOLIDATION TEST RESULTS TABLE I - SUMMARY OF LABORATORY TEST RESULTS Chen @Northern, Inc Consulting Engineers and Scientists i 5a -2- and the subsoil conditions encountered. Design parameters and a of geotechnical engineering considerations related to construction of the residence are included in the report. N •.• ••. aqO.•t • At the time of our study, design plans for the residence were in progress. 4 The building was proposed in the area roughly between the exploratory boring locations shown on Fig. 1 but may now be located about 50 to 75 feet further north. We Understand the proposed residence will be one and two story wood frame construction over partial walkout basement and partial crawl space. We assume excavation for the building will have a maximum cut depth of one level, about 10 feet bejow the existing ground surface. For the purpose of our analysis, i foundation loadings for the structure were assumed to be relatively light and F typical of the proposed construction type. If building loadings, location or grading plans are significantly different from thoseidescribed above, we should be notified to reevaluate the recomnen- dationsoo ined in this report. SITE OONDITIONS At the: time of our field work the site was vacant. Patches of snow covered the ground 'surface. Vegetation consists of scrub oak, sagebrush, grass and weeds. The property slopes fairly uniformly and moderately to the northeast at a grade of Wbout 20% in the original building area but steepens to about 300-. to 40% east of the proposed building site. There are localized irregularities in Chen@Northern, Inc. Consulting Engineers and Scientists OONCLUSICM The subsoils encountered at the site, below organic topsoil, it consisted of weathered claystone and clay overlying claystone-siltstone bedrock. The pr-oposed residence can be founded with spread footings bearing on the bedrock, below all topsoil and weathered claystone, designed 94 for an allowable bearing pressure of 4000 psf. Due to the swell potential of the weathered claystone and clay, these soils should not be used for support of slabs -on -grade. other design and construction criteria relating to geotechnical aspects of the site are presented in the body of the 14 report. M This report presents the results of a subsoil study for a proposed residence to be located on Lot 7, Block 7, Brush Creek Village, Pitkin County, Colorado. The project site is shown on Fig. 1. The purpose of the study was to develop recommendations for foundation design. The study was conducted in accordance with our agreement for geotechnical engineering services to Joan Teige, dated April 16, 3.991. A field exploration program consisting of exploratory borings was conducted to obtain information on subsurface conditions. Samples obtained during the afield exploration were tested in the laboratory to determine compressibility or swell characteristics and classification of the on-site soils and bedrock. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths and allowable pressures for the proposed building foundation. The results of the field exploration and laboratory testing are presented in the report. This report has been prepared to summarize the data obtained during this study and to present our conclusions and recommendations based on the proposed Chen @Northern, Inc. Consulting Engineers and Scientists • 10 f -11y) -W N ff 6­07TI-61 YY CC ZZ ; The subsoil conditions encountered at the site are shown graphically on Fig. 2. Belowiabout 2 feet of topsoil, weathered claystone and clay subsoils, hard claystione*-siltstone shale bedrock was encountered. The soils and bedrock encountered in the borings are similar to those encountered at other nearby lots. The upper weathered claystone and clay soils typically are medium plasticity and possess a swell potential. The underlying bedrock is typically silty and not as expansive as the clay materials. The soils found on Int 6 were mostly clay and shifting the building site in this direction could encounter deeper clays. The clay and shale bedrock are generally not suitable materials for a conventional infiltration septic disposal system. Laborato testing performed on samples obtained during the field exploration included in-situ moisture content and dry density, and liquid and plastic limit testing. Swell -consolidation testing was performed on a relatively undisturbed drive sample of the upper clay soil. The swell -consolidation test results, presented on Fig. 4, indicate a high expansion potential when wetted under a constant relatively light surcharge. Undisturbed sampling of the shale bedrock was not possible due to the hardness and dryness of the material. The hard shale does not appear to be expansive. The laboratory testing is summarized in Table I. The upper topsoil and clay or weathered claystone were moist and the underlying shale was slightly moist. Water levels indicated on the log of Boring 1 are probably the result of recent surface runoff and infiltration caused by snowmelt. The water could also be flowing through bedding and other joints in the rock. Chen @Northern, Inc. Consulting Engineers and Scientists -3 - the ground surface slope. Elevation change across the building area is about 10 to 15 feet and on the order of 75 to 100 feet across the entire lot. The property is located within a geologic sensitive area. A relatively recent and active landslide has been identified on Int 6 to the west of the property by Nicholas Lampiris, consulting geologist. No evidence of relatively recent and fairly large scale slope movement was observed within the proposed building area. Regional mapping by Bryant (1972) indicates the near surface bedrock is the Mancos Shale Formation which has a bedding dip on the order of 150 (25%) to the northeast. iyaof IF oil W•� :: rr • . The field exploration for the project was conducted on April 17, 1991. Two exploratory borings were drilled at the approximate locations shown on Fig. 1 to evaluate the subsurface conditions. The borings were advanced with a 4 -inch diameter continuous flight auger powered by a track-m-3unted QHE-45 drill rig. The borings were logged by a representative of Chen -Northern, Inc. Samples of the subsoils were taken with 1 3/8 -inch and 2 -inch I.D. spoon samplers. The samplers were driven into the subsoils at various depths with blows from a 140 -pound hammer falling 30 inches. This test is similar to the standard penetration test described by AS -IM Method D-1586. The penetration resistance values are an indication of the relative density or consistency of the subsoils. Depths at which the samples were taken and the penetration resistance values are shown on the Logs of Exploratory Borings, Fig. 2. The samples were returned to our laboratory for review by the project engineer and i testing. r -- I 14 Chen@Northern, Inc. Consulting Engineers and Scientists -6- 4) Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost Protection. Placement of foundations at least 42 inches below the exterior gradelis typically used in this area. 5) Prior to the footing construction, topsoil, weathered claystone and clay subsoils, and loose or disturbed soils or bedrock should be removed and the footing bearing level extended down to competent bedrock. If water seepage is encountered in the excavation, the footing areas should be dewatopred before concrete placement. 6) A representative of the soil engineer should observe all footing excavations prior to concrete placement to evaluate bearing conditions and the p�esence of expansive materials. WK, RI It : M m a�;DIY: �.I�.. J. R Found4tion walls and retaining structures which are laterally supported and can be OTected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit Weight of 65 pcf for backfill consisting of the on-site fine grained soils and 45 pcf for backfill consisting of imported granular materials. Cantilevered retaining structures which are separate from the residence and can ! be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for a lateral earth pressure computed on the basis of an equivailent fluid unit weight of 50 pcf for backfill consisting of the t on-site fine grained soils and 40 pcf for backfill consisting of imported granular materials. 0 Chen ONorthern, Inc. Consulting Engineers and Scientists -5- OW410 Z u • •1 AR4 —ykk V I%,! I Df Z I Wily M it,ti Considering the subsurface conditions encountered in the exploratory borings and the nature of the proposed construction, we recommend the residence be founded with spread footings placed on undisturbed claystone-siltstone bedrock. The weathered claystone and clay subsoils have a high expansion potential when wetted under light loading conditions and are not recommended for support of footings or slabs -on -grade. Surface runoff and utility leakage are possible sources of water which could cause wetting. The design and construction criteria presented }-)elow should be observed for a spread footing foundation system. The constru(:tion criteria should be considered when preparing project documents. 1) Footings placed on the claystone-siltstone bedrock can be designed for an allowable bearing pressure of 4000 psf. Due to the potential for low expansion potential, the footings should also be sized for a minimum dead load pressure of 800 psf. Based on experience, we expect settlement or heave of footings designed and constructed as discussed in this section will be about 1 inch or less. 2) The footings should have a minimum width of 12 inches for continuous footings and 18 inches for isolated pads. 3) Continuous foundation walls should be reinforced top and bottom to span local anomalies. One method of analysis is to design the foundation wall to span an unsupported length of at least 12 feet. Foundation walls acting as retaining structures should also be designed to resist a lateral earth pressure as discussed in the "Foundation and Retaining Walls" section of this report. Chen 0- Inc. Consulting Engineers ano Scientists -8 - We recommend imported granular soils for backfilling foundation walls and retaining structures because their use results in lower lateral earth pressures and the backfill may be incorporated into the underdrain system. Subsurface drainage re0cmTendations are discussed in more detail in the "Underdrain System" section of this report. Inported granular wall backfill should be approved for use by the soils engineer. Granular materials should be placed to within 2 feet of the grouted surface and to a minimum of 2 feet beyond the walls. The upper 2 feet of tl wall backfill should be a relatively impervious soil such as the on-site clay to limit surface water infiltration into the backfill. IN FMOR SLABS LyJ The on-site weathered claystone and clay soils possess a high expansion INpotential and slab heave could occur if these soils were to become wet. Slab -on -grade construction may be used provided precautions are taken to limit potential movement and the risk of distress to the building is accepted by the Iowner. The Weathered claystone and clay soils should be removed from slab areas. The underlying shale bedrock may also possess an expansion potential that could heave floor slabs. A positive way to reduce the risk of slab movement, which is commonly Used in the area, is to construct structurally supported floors over I crawl space. Jim To reduce the effects of some differential movement, nonstructural floor slabs shoulc be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Interior non-bearing partitions resting on floor slabs should be provided with a slip joint at the bottom of the wall so that, if the slab moves, the movement cannot be transmitted i to the upper'structure. This detail is also important for wallboards, stairways 10 Chen @Northern, Inc. Consulting Engineers and Scientists -7 - All foundation and retaining structures should be designed for appropriate surcharge pressures such as adjacent buildings, traffic, construction materials and equipment. The pressures recommended above assume drained conditions behind the walls and a horizontal backfill surface. The buildup of water behind a wall or an upward sloping backfill surface will increase the lateral pressure imposed on a foundation wall or retaining structure. An underdrain should be provided to prevent hydrostatic pressure buildup behind walls. On site soils used as backfill should be placed in uniform lifts and compacted to at least 90% of the maximum standard Proctor density at a moisture content slightly above optimum. Care should be taken not to overcompact the backfill or use large equipment near the wall since th*,s could cause excessive lateral pressure on the wall. Some settlement of deep foundation wall backfill should be expected even if the material is placed correctly and result in distress to facilities constructed on the backfill. The lateral resistance of foundation or retaining wall footings will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.4. Passive pressure against the sides of the footings can be calculated using an equivalent fluid unit weight of 300 pcf. The coefficient of friction and passive pressure values recommended above assume ultimate soil strength. Suitable factors of safety should be included in the design to limit the strain which will occur at the ultimate strength, particu- larly in the case of passive resistance. Fill placed against the sides of the footings to resist lateral loads should be compacted to at least 95% of the maximum standard Proctor density at a moisture content near optimum. Chen @Northern, Inc. Consulting Engineers and Scientists ® WO -10- C wetting by an underdrain system. The drain should also act to prevent buildup of hydrostatic pressures behind foundation walls. The unlerdrain system should consist of a drainpipe surrounded by free - draining granular material placed at the bottom of the wall backfill. The drain lines should', be placed at each level of excavation and at least 1 foot below lowest adjacent finish grade, and sloped at a minimum 1% grade to a suitable gravity outlOt. Free -draining granular material used in the drain system should consist of minus 2 -inch aggregate with less than 50% passing the No. 4 sieve and less than A passing the No. 200 sieve. The drain gravel should be at least 2 feet deep. SITE GRADING The risk of construction induced slope instability at the site appears low provided the building is located in the less steep terrain as planned and cut and fill depths are limited. We assume the cut depth for the basement level will not exceed one level, about 10 feet. The bedrock bedding dip is to the northeast and unfavorable to temporary steep cut slope stability. We don't expect there will be stab.lity problems with dry slope conditions. Fills should be limited to about 6 tb 8 feet deep, especially at the downhill side of the residence where the slope steepens. Embankment fills should be compacted to at least 95% of the maximum standard Proctor density near optimum moisture content. Prior to fill placement the subgrade should be carefully prepared by removing all vegetation and topsoil and compacting to 95% standard Proctor density. The fill should be benched into the portions of the hillside exceeding 20% grade. Permanent unretained cut and fill slopes should be graded at 2 horizontal to 1 vertical or flatter. The risk of slope instability will be increased if ChenONorthern, Tne. Consulting Engineers and Scientists 1W -9- 14 and door frames. Slip joints which will allow at least 1 1/2 inches of vertical INmovement are recommended. Floor slab control joints should be used to reduce damage due to shrinkage cracking. Slab reinforcement and control joints should inbe established by the designer based on experience and the intended slab use. A minimum 4 -inch layer of free -draining gravel should be placed immediately beneath basement level slabs -on -grade. This material should consist of minus 2 -inch aggregate with less than 50% passing the No. 4 sieve and less than 2% passing the No. 200 sieve. The free -draining gravel will aid in drainage below the slabs and should be connected to the perimeter unde_rdrain system. Required fill beneath slabs should consist of a suitable nonexpansive imported material. The fill should be spread in thin horizontal lifts, adjusted to at or above optimum moisture content, and compacted to at least 95% of the maximum standard Proctor density. All vegetation, topsoil, weathered claystone subsoils and loose or disturbed soil should be removed prior to fill placement. The above recommendations will reduce the effects of slab movement if soils underlying slabs -on -grade become wet but will not totally eliminate the risks if slab heave occurs. All plumbing lines should pass pressure testing before backfilling to help reduce the potential for wetting. UNDERDRAIN SYSTEM IN Although most of the bedrock and soils encountered during our exploration INwere dry, it has been our experience in mountainous areas and where clay soils INare present and bedrock is shallow, that local perched groundwater may develop during times of heavy precipitation or seasonal runoff. Frozen ground during 10 spring runoff can create a perched condition. Therefore, we recommend below WOgrade construction such as crawl space and basement areas be protected from 0 Chen@Northern, Inc. Consulting Engineers and Scientists -12 - LIMITATIONS This report has been prepared in accordance with generally accepted soil and foundation engineering practices in this area for use by the client for design purpmes. The conclusions and reccmien lations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Fig. 1, the proposed type of construction and our experience ih the area. The nature and extent of subsurface variations across the site may not become evident until excavation is performed. If during construction, fill, soil, rock or water conditions appear to be different from those described herein, this office should be advised at once so reevaluation of the recommendations may be made. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the soil engineer. Sincerely, 1 C HEN-NORTHEW, INC. PA LL TC.1 •�9 i Thomas L. Allen 15222 :* Reviewed By :$ - �w-�/l��-_ �r•OF COL�� Steven L. Pawlak TLA/lr 19 REFERENCES Bryant, B., 1072, Geologic Map of the Highland Peak Quadrangle, Pitkin County, Colorado, U.S.G.S. Map GQ 932. INChen @Northern, Inc. Consulting Engineers and Scientists OW -11- seepage is encountered in cuts and flatter slopes may be necessary. If seepage is encountered in permanent cuts, an investigation should be conducted to determine if the seepage will adversely affect the cut stability. This office should review site grading plans for the project prior to construction. The following drainage precautions should be cbstxved during construction and maintained at all times after the residence has bean completed: 1) Excessive wetting or drying of the foundation excavations and underslab areas should be avoided during construction. Drying could increase the expansion potential of the soils. 2) Exterior backfill should be adjusted to near optimum moisture and compacted to at least 95% of the maximum standard Proctor density in pavement areas and to at least 90% of the maximum standard Proctor density in landscape areas. Free -draining wall backfill should be capped with about 2 to 3 feet of the on-site soils to reduce surface water infiltration. 3) The ground surface surrounding the exterior of the building should be sloped to drain away from the foundation in all directions. We recomTend a minimum slope of 12 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first 10 feet in paved areas. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. Chen@Northern, Inc. Consulting Engineers and Scientists 75 70 .1 55 50 i Boring 1 Boring 2 Elev. - 79' Elev. - 69' 1 80 19 50/4 _WC=6 LL=24 PI=5 75 26 50/4 70 50/3 24/6, 28/3 WC=11 DD= 121 65 50/3 50/3 a� w 60 50/3 50/6 WC=4 LL=29 PI=13 55 50/3 Note: Explanation of symbols presented on Fig. 3. 50 4 251 91 1 Cllen@Northern,Inc. LOGS OF EXPLORATORY BORINGS Fig. 2 aLb , � 1. LEGEND: ® Topsoil; clay and weathered shale, organic, soft dark brown. © Clay, (CL); hard, slightly moist, brown, medium plastic. . Claystone-Siltstone Bedrock; very hard, slightly moist, gray, low plasticity, fractures. Relatively undisturbed drive sample, 2 -inch I.D. California liner sample. Drive sample, standard penetration test (SPT), 1 3/8 -inch I.D. split spoon sample, ASTM D-1586. 50/4 Drive sample blow count; indicates that 50 blows of a 140 -pound hammer falling 30 inches were required to drive the California or SPT sampler 4 inches. 1,19 Free water level in boring and number of days after drilling measurement was made. NOTES: 1. Exploratory borings were drilled on April 17, 1991 with a 4 -inch diameter continuous flight power auger. 2. Locations of exploratory borings were measured approximately by pacing from features shown on the site plan provided. 3. Elevations of exploratory borings were measured by hand level and refer to the bench mark on Figure 1. 4. The exploratory boring locations and elevations should be considered accurate only to the degree implied by the method used. 5. The lines between materials shown on the exploratory boring logs represent the approximate boundaries between material types and transitions may be gradual. 6. Water level readings shown on the logs were made at the time and under the conditions indicated. Fluctuations in water level may occur with time. 7. Laboratory Testing Results: VIC = Water Content (%) DD = Dry Density (pcf) LL = Liquid Limit M PI = Plasticity Index (�) 14 251 91 1 Chen@Northern, Inc. I LEGEND AND NOTES I Fig. 3 1 SITE• IDI AIA/ �°° SCAL£.• 1 " = 20' �o \ EXISTING CONTOUR (TYP) \ � EXISTING GRADE CLEANOUT \ OUTLINE OF E. T QED PVC SEWER PIPE ASTA4, 2729, SLOPE 90 M/ V` /4" PER FT \ \ \ \ \ 2: 1 SLOPE -� FINISHED GRADE PROPOSE,Q CONTOUR TVP. \ \ \ \ \ -\ ( ) PROVIDE SW TO DIVERT �� \ \ �' \\\\ ♦\ \\\ \\ \ \ \ RUN-OFF AROUND E.T. BED 1000 GAL2_-ON SEPTIC TANK \ ♦ \ \ \\ \ \ \ \ \ o LAP LINER 1 PROVIDE CL�A OO UT UNLESS PROWDED FOR INSIDE HOU-')E---- \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ .3-BEDR6VM \ \ \ \ \ \ \�•� � � \RESIDENCE\ 2' \ \ \ \ O�AINA GE SWALE (1�YP.) \ \ 4" SOLID WALL PVC SL OPE 0"/FT. \ \ \ 1 \ \ 4" PERFORATED PVC \ SLOPE 0 FT (TVP.) SEPTIC° TAN°KM `O JV 3' 6' 6' - 6' 6' 6' 3' -- -- SANDY TOPSOIL FROM 6" AT -T8-2"-AT VARIES CENTER GES AN i BOTTOM OFBED TO BE CONSTRUCTED /N NATURAL GROUND, BELO' TOPSOIL 7" WASHED SAND BOTTOM OF BED SHALL --J BE LEVEL 0. 1 f, SCARIFY BEFORE PLACING ROCK SECTION A A SCALE-.- I"= 3' 4" PERFORATED PVC SLOPE 0 /FT (TVP.) 13" OF 1/2" TO 2-1/2" CLEAN ROCK 10 MIL. PVC LINER 2 - MIRAFI FABRIC OR 4" OF STRAW 2:1 SL OPE LAP LINER I' CLEAN-OUT DETAIL FL OW FROM HOUSE- AIR VENT (2 REO D) SEE DETAIL EVA PO TRA NSPIRA TION BED DETAIL 5;,14LE: I"= 10' 4" TEE, DO NOT GLUE 4" AIR VENT- GENERAL ENT GENERAL NOTES DESIGN CAL COLA TIONS N SANDY TOPSOIL VARIES 1, ALL MATERIALS, INSTALLATION PRACTICES, SETBACK REQUIREMENTS, ETC., 11, CAST IRON PIPE OR PIPE OF EQUAL STRENGTH OR OTHER PIPE PROPERLY 1. DETERMINE DESIGN FLOW FROM 6" AT CENTER SHALL COMPLY WITH THE PITKIN COUNTY INDIVIDUAL SEWAGE DISPOSAL SUPPORTED TO PREVENT FAILURE BY SETTLING SHALL EXTEND FROM TANK FOR TO 2" AT EDGES i -SEED TOPSOIL SYSTEM REGULATIONS. NOTES: A DISTANCE OF AT LEAST FIVE FEET (5) FROM THE INLET AND OUTLET 3 BEDROOM HOME, 2 PERSONS/BEDROOM, 75 GALLONS/PERSON/DAY I 1. BED AND SEPTIC TANK MAY BE FIELD ADJUSTED TO \ \ I ADJUSTED TO BEST FIT THE SITE PROVIDED MINIMUM \ 2. \ o SETBACKS ARE MET AND ENGINEER AND PITKIN COUNTY Q = 3 * 2 * 75 = 450 GPD —ILI ARE NOTIFIED. \ \ 12. THE CONTRACTOR AND OWNER SHALL TAKE WHATEVER MEASURES ARE NECESSARY \ _1-1 \ — - 2. ONLY STRAIGHT RUNS OF SEWER PIPE ARE ALLOWED. \ BE PLACED IN FILL. TO ASSURE THAT (a) SEPTIC TANK AND SEWER LINES ARE COMPLETELY WATER 2. 259 FLOW REDUCTION FOR USE OF WATER LOCATE CLEANOUT AT EACH HORIZONTAL AND/OR VERTICAL \ \ FL 0W 7-0 CHANGE IN DIRECTION. TIGHT, AND (b) THE SYSTEM /S TO BE INSTALLED TO PREVENT FREEZING OF \ SAND STRATA J. PROVIDE ADEQUATE SURFACE WATER DIVERSION TO ASSURE THAT RUN-OFF TANKCDI 450 * 0.75 = 337.5 GPD M/RAF/ FABRIC DOES NOT ENTER THE EVAPO-TRANSPIRATION/ABSORPTION BED. CLEAN-OUT DETAIL FL OW FROM HOUSE- AIR VENT (2 REO D) SEE DETAIL EVA PO TRA NSPIRA TION BED DETAIL 5;,14LE: I"= 10' 4" TEE, DO NOT GLUE 4" AIR VENT- GENERAL ENT GENERAL NOTES DESIGN CAL COLA TIONS N SANDY TOPSOIL VARIES 1, ALL MATERIALS, INSTALLATION PRACTICES, SETBACK REQUIREMENTS, ETC., 11, CAST IRON PIPE OR PIPE OF EQUAL STRENGTH OR OTHER PIPE PROPERLY 1. DETERMINE DESIGN FLOW FROM 6" AT CENTER SHALL COMPLY WITH THE PITKIN COUNTY INDIVIDUAL SEWAGE DISPOSAL SUPPORTED TO PREVENT FAILURE BY SETTLING SHALL EXTEND FROM TANK FOR TO 2" AT EDGES i -SEED TOPSOIL SYSTEM REGULATIONS. A DISTANCE OF AT LEAST FIVE FEET (5) FROM THE INLET AND OUTLET 3 BEDROOM HOME, 2 PERSONS/BEDROOM, 75 GALLONS/PERSON/DAY I ENDS. 2. THE ET BED SHALL BE CONSTRUCTED SO THAT THE BOTTOM IS LEVEL Q = 3 * 2 * 75 = 450 GPD —ILI f/- 0. 7'. PLACE BED IN NATURAL GROUND; NO PORTION OF THE BED SHALL 12. THE CONTRACTOR AND OWNER SHALL TAKE WHATEVER MEASURES ARE NECESSARY _1-1 — - BE PLACED IN FILL. TO ASSURE THAT (a) SEPTIC TANK AND SEWER LINES ARE COMPLETELY WATER 2. 259 FLOW REDUCTION FOR USE OF WATER SAVINGS DEVICES. TIGHT, AND (b) THE SYSTEM /S TO BE INSTALLED TO PREVENT FREEZING OF SAND STRATA J. PROVIDE ADEQUATE SURFACE WATER DIVERSION TO ASSURE THAT RUN-OFF ALL PRESSURE AND GRAVITY SEWER LINES. 450 * 0.75 = 337.5 GPD M/RAF/ FABRIC DOES NOT ENTER THE EVAPO-TRANSPIRATION/ABSORPTION BED. �0 - ° ° 13. THE PITKIN COUNTY ENVIRONMENTAL HEALTH DEPARTMENT AND THE ENGINEER J. SEPTIC TANK SIZE FOR 3 BEDROOM HOME = 1000 GALLONS o c-� 4PERFORATED PVC - ROCK MOUNDED ° 4. » �� STONE SHALL BE 1/2 TO 2 1/2 SCREENED ROCK. SHALL BE NOTIFIED WHEN CONSTRUCTION COMMENCES AND KEPT ABREAST OF 4. ALLOWABLE LOADING RATES: � DISTRIBUTION PIPING ABOVE PIPE THE CONSTRUCTION PROGRESS SO THAT SUFFICIENT INSPECTION CAN BE PERFORATIONS 5. SAND SHALL BE 0.5 TO 1.0 MM EFFECTIVE SIZE WITH A UNIFORMITY PERFORMED TO ASSURE CONFORMANCE WITH THESE PLANS. PROVIDE A MINIMUM FOR EVAPO-TRANSPIRATION USE STANDARD ET RATE FROM 32 PAN ROCK STRATA COEFFICIENT OF 4 OR LESS. OF 48 HOURS NOTICE TO EACH. OF 0. 1.35 GALLONS/SF./DAY °`�` o °� °a 6. THE RECOMMENDED BED SEEDING /S BLUE GRASS AT 4 TO 6 LBS./1000 14, ORIGINAL MAPPING SUPPLIED BY OWNER. FIELD VERIFY GRADES AND 5. DETERMINE BED SIZE.• SQ.FT. ALL OTHER AREAS DISTURBED BY CONSTRUCTION SHALL BE RESEEDED LOCATIONS OF SEWAGE DISPOSAL COMPONENTS IDENTIFIED FOR 10 MIL, PVC LINER WITH NATIVE GRASSED TO PREVENT EROSION. APPLICABILITY TO CURRENT FIELD CONDITIONS. ALL FIELD VERIFICATIONS MUST BE PERFORMED PRIOR TO CONSTRUCTION. NOTIFY ENGINEER OF ANY AREA = 0/0. 135 AIR l/ENT DE TAIL 7. THE LOCATION OF THE BED MAY BE ADJUSTED IN THE FIELD TO BETTER FT DISCREPANCIES THAT MAY EXIST. = 2500 S.F. THE SITE, PROVIDED ALL SETBACKS ARE MET SCALE: I"= 1'-0" 15. SUBSTITUTION OF MATERIALS /S ACCEPTABLE PROVIDED THE PITKIN COUNTY USE 36' X 70' BED SIZE, EFFECTIVE AREA = 2520 S.F. IlilE����ii 8. „ DRAIN HOLES IN 4 PERFORATED PIPE TO BE AT 30 SPACING (2 HOLES PER ENVIRONMENTAL HEALTH DEPARTMENT AND THE ENGINEER ARE NOTIFIED OF -D ASPS IBJ/PITKIN 13 SPACING, 71,32" DIA, LOCATED DOWNWARD). OR USE STANDARD ASTM 2729 / ) SUCH AND ARE IN FAVOR OF SUCH SUBSTITUTIONS. *SIZE BED FOR FUTURE ONE BEDROOM GARAGE APARTMENT* ' ®4 �` DRAIN & LEACHFIELD PIPE. BED SIZED FOR 833.3,3 S. F. PER BEDROOM, ADD 8,33.33 SF. Vli�ONI ENTAL HEALTH . . � 9. 4" PVC TEES SHOULD NOT BE GLUED TO ENABLE OBSERVATIONS OF WATER TO CALCULATED BED AREA = 3,333.,33 S.F. LL 5 LEVEL IN SYSTEM AND TO REMOVE EXCESS SALTS ACCUMULATION OR SURPLUS" 3c WATER, IF NECESSARY. USE 36' X 93' BED SIZE, EFFECTIVE AREA = 3348 S.F. PROVED �\ 10. USE RISERS AS NEEDED TO BRING SEPTIC TANK ACCESS HATCH WITHIN 6" OF FINISHED GRADE.