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Home My WebLink About03565r . f 1 GARFIELD COUNTY BUILDING AND SANITATION DEPARTMENT 109 8th Street Suite 303 Glenwood Springs, Colorado 81601 Phone (303) 945·8212 INDIVIDUAL SEWAGE DISPOSAL PERMIT PROPERTY Permit N~ 3565 Aaaeaeor'a Parcel No. This does not constitute a building or use permit. S'wffT~~G~~45'--'iS'] tO System Location_CO""""'""--"S<',_'f_,___,.Q..a.1 f\....__...l ...,_)A,,._~'l-J-'11.12£""'---'/.41.J:f-.._'IF.=..,)1-· _Q~,,.S...L_ ___________ _ Legal Description of Assessor's Parcel No. .;l...) 'f 5 -CJ.;l{ -() b -OS (., SYSTEM DESIGN ~~at11l< ~~v-..ci. ~IA. D dF'f ______ Septic Tank Capacity (gallon) ______ .Qt her ______ Percolation Rate (minutes/inch) Number of Bedrooms (or other) ____ _ Required Absorption Area -See Attached Special Setback Requirements: Date _____________ Inspector ___________________________ _ FINAL SYSTEM INSPECTION AND APPROVAL (as installed) Call for Inspection (24 hours notice) Before Covering Installation System Installer ________________________________________ _ Septic Tank Capacity ______________________________________ _ Septic Tank Manufacturer or Trade Name------------------------------- Septic Tank Access within 8" of surface -------------------------------- Absorption Area---------------------------------------- Absorption Area Type and/or Manufacturer or Trade Name -------------------------- Adequate compliance with County and State regulations/requirements _____________________ _ Other -------------------------------------------- Inspector '5:JimCJe8£!.< &ooh /fl~ RETAIN WITH RECEIPT RECORDS AT CONSTRUCTION SITE •CONDITIONS: 1. All installation must comply with all requirements of the Colorado State Board of Health Individual Sewage Disposal Systems Chapter 25, Artocle 10 C.R.S. 1973, Revised 1984. 2. This permit is valid only for connection to structures which have fully complied with County zoning and building requirements. Con- nection to or use with any dwelling or structures not approved by the Bu tiding and Zoning office shall automatically be a violation or a requirement of the permit and cause for both legal action and revocation of the permit. 3. Any person who constructs. alters, or installs an individual sewage disposal system in a manner which involves a knowing and material variation from the terms or specifications contained in the application of permit commits a Class I, Petty Offense ($500.00 fine - 6 months in jail or both). White· APPLICANT Yellow· DEPARTMENT I Il\DIVIDUAL SEWAGE DISPOSAL SYSTEM APPUCATION OWNER '4<-,'pf R± bt.\\E ~{2,E.IZ.~ ADDRESS ~ij C)~ hlq~i:"" LAn~ CONTRACTOR ~u'beR:_ ~-QiUL'(Lo.._ ADDREss Q()~ u.. a\a N~~\)'<L-\c1...'('\'L PHONE __ C\_,_~~5._<4"'-'l_,_\_,_,Q..__ __ PERMIT REQUEST FOR tf.J NEW INSTALLATION ( ) ALTERATION ( )REPAIR Attach separate sheets or report showing entire area with respect to surrounding areas, topography of area, habitable building, location of potable water wells, soil percolation test holes, soil profiles in test holes (See page 4). LOCATION OF PROPOSED FACILITY: Near what City ofTown_~2.Jj~llilJ~~...,.:~L..lJ~~~Uc.__ _ _J2!;~!U.QL__l~!..1.__J:~-'- Legal Description or Address JJO:lL2.!.~~t..S:~~~~~~~~~~~IB!llf:rLl:WL:.::L-1:'lloS ~t\t.- WASTES TYPE: ~DWELLING ( ) TRANSIENT USE ( ) COMMERCIAL OR INDUSTRIAL ( ) NON-DOMESTIC WASTES ( ) OTHER-DESCRIBE ______________ _ BUILDING OR SERVICE TYPE:___.~_,,.,,~~>--___;:_5,1--'( r'---f)=--w--'e'-l_\ i-~-+---------- Number of Bedrooms ----'l'~~~f-------------Number of Persons -""cK_,,_ ___ _ ( ' Garbage Grinder ~ Automatic Washer SOURCE AND TYPE OF WATER SUPPLY: ( ) WELL 9Q Dishwasher ( ) SPRING ( ) STREAM OR CREEK If supplied by Community Water, give name of supplier:_.!_..1_)LLF-ST~~B~A:i-ilo..2o<-<li>.,~,..---------- DISTANCE TO NEAREST COMMUNITY SEWER SYSTEM: ___________ _ Was an effort made to connect to the Community System? ______________ _ A site olan is reauired to be submitted that indicates the followiug MINIMUM distances: Leach Field to Well: 100 feet Septic Tank to Well: SO feet Leach Field to Irrigation Ditches, Stream or Water Course: SO feet Septic System to Property Lines: 10 feet YOUR INDIVIDUAL SEWAGE DISPOSAL SYSTEM PERMIT WILL NOT BE ISSUED WITHOUT A SITE PLAN. GROUND CONDITIONS: Depth to first Ground Water Table ______________________ _ Percent Ground Slope __________________________ _ 2 I TYPE O~ IND~UAL ~EWAGE DISPOSAL SYSTEM PROPOSED: ( fJ SEPTIC TANK ( ) AERATION PLANT ( ) VAULT ( ) VAULT PRIVY ( ) COMPOSTING TOILET ( ) RECYCLING, POT ABLE USE ( ) PIT PRIVY ( ) INCINERATION TOILET ( ) RECYCLING, OTHER USE ( ) CHEMICAL TOILET ( ) OTHER-DESCRIBE ___________ _ FINAL DISPOSAL BY: ( ~) ABSORPTION TRENCH, BED OR PIT ( ) UNDERGROUND DISPERSAL ( ) ABOVE GROUND DISPERSAL ( ) EV APOTRANSPIRATION ( ) SAND FILTER ( ) WASTEWATERPOND ( ) OTHER-DESCRIBE, ____________________ _ WILL EFFLUENT BE DISCHARGED DIRECTLY INTO WATERS OF THE STATE? ______ _ PERCOLATION TEST RESULTS: (To be completed by Registered Professional Engineer, if the Engineer does the Percolation Test) Minutes. ____ -1per inch in hole No. I Minutes ______ ,per inch in hole NO. 3 Minutes per inch in hole No. 2 Minutes per inch in hole NO. _ Name, address and telephone ofRPE who made soil absorption tests: _____________ _ Name address and telephone ofRPE responsible for design of the stem: '}'ch fYIL( e .se (( G ol<., cl tt'f ll1eye« . ~ u.i~ ~ ~ <e,.~ y;((,,c/ Geo+e,4,. 5o cif!._,l<;rj G ·~. Applicant acknowledges that the completeness of the application is conditional upon such further mandatory and additional tests and reports as may be required by the local health department to be made and furnished by the applicant or by the local health department for purposed of the evaluation of the application; and the issuance of the pennit is subject to such terms and conditions as deemed necessary to insure compliance with rules and regulations made, information and reports submitted herewith and required to be submitted by the applicant are or will be represented to be true and correct to the best of my knowledge and belief and are designed to be relied on by the local department of health in evaluating the same for purposes of issuing the permit applied for herein. I further understand that any falsification or misrepresentation may result in the denial of the application or revocation of any permit granted based upon said application and in legal action for perjury as provided by law. Date 2· 3d. d/ PLEASE DRAW AN ACCURATE MAP TO YOUR PROPERTY!! 3 ' · ·HP GeC!>tcch April 25, 2001 Bob Deherrera 1179 Sweetwater Road Gypsum, Colorado 81637 Hepworth· Pawlak Geotcchnical, Inc. 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 hpgeo@hpgeotech.com Job No. IOI 299 Subject: Subsoil Study for Foundation Design and Percolation Test, Proposed Residence, Lof 56, Westbank Mesa, Garfield County, Colorado. Dear Mr. Deherrera: As requested, Hepworth-Pawlak Geotechnical, Inc. performed a subsoil study and percolation test for foundation and septic disposal designs at the subject site. The study was conducted in accordance with our agreement for geotechnical engineering services to you dated April 13, 2001. The data obtained and our recommendations based on the proposed construction and subsurface conditions encountered are presented in this report. Proposed Construction: The proposed residence will be a two story split level, wood frame structure located in the building envelope shown on Fig. 1. Ground floors will be a combination of structural over a crawlspace and slab-on-grade for the partial basement. There will be a detached garage with a slab-on-grade floor. Cut depths are expected to range between about 3 to 6 feet. Foundation loadings for this type of construction are assumed to be relatively light and typical of the proposed type of construction. The septic disposal system is proposed to be located to the east of the building area. If building conditions or foundation loadings are significantly different from those described above, we should be notified to re-evaluate the recommendations presented in this report. Site Conditions: The site was vacant at the time of our field work. The ground surface is relatively flat with a gentle slope down to the north-northeast. There is about 10 to 12 feet of elevation difference across the lot. The Robertson irrigation ditch is located downhill to the north and northeast of the lot. There is some fill along the uphill side of the lot due to filling for Old Native Lane. Most of the lot appears to be natural. Vegetation consists of scattered sagebrush, grass and weeds. Bob Deherrera April 25, 2001 Page 2 Subsurface Conditions: The subsurface conditions at the site were evaluated by excavating two exploratory pits in the building area ai:td one profile pit in the septic disposal area at the approximate locations shown on Fig. 1. The logs of the pits are presented on Fig. 2. The subsoils encountered, below about 2 to 2 1/z feet of topsoil (stiff sandy clayey silt root zone), consist of medium stiff to stiff sandy clayey silt to the pit depths of 8 to 81/i feet. Results of consolidation testing performed on relatively undismrbed samples of the silt, presented on Figs. 3 and 4, indicate low compressibility under existing moisture conditions and light loading and a low collapse potential (settlement under constant load) when wetted. The samples showed moderate to high compressibility upon increased loading after wetting. Atterberg limits testing indicated the soils to have low plasticity. No free water was observed in the pits at the time of excavation and the soils were slightly moist. Foundation Recommendations: Considering the subsoil conditions encountered in the exploratory pits and the riamre of the proposed construction, we recommend spread footings placed on the undisturbed namral soil designed for an allowable soil bearing pressure of 1,500 psf for support of the proposed residence. The soils tend to compress after wetting and there could be some post-construction foundation settlement. The settlement would depend on the depth and extent of subsurface wetting and could be 1 to 2 inches or more. Footings should be a minimum width of 18 inches for continuous walls and 2 feet for columns. Loose and dismrbed soils encountered at the foundation bearing level within the excavation should be removed and the footing bearing level extended down to the undismrbed namral soils. The exposed subgrade should be moistened and compacted prior to placing concrete. Exterior footings should be provided with adequate cover above their bearing elevations for frost protection. Placement of footings at least 36 inches below the exterior grade is typically used in this area. Continuous foundation walls should be reinforced top and bottom to span local anomalies such as by assuming an unsupported length of at least 12 feet. Foundation walls acting as retaining structures should be designed to resist a lateral earth pressure based on an equivalent fluid unit weight of at least 50 pcf for the on-site soil as backfill. Floor Slabs: The namral on-site soils, exclusive of topsoil, are suitable to support lightly loaded slab-on-grade construction. The soils are compressible when wetted. To reduce the effects of some differential movement, floor slabs should be separated from H-P GEOTECH Bob Deherrera April 25, 2001 Page 3 all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage cracking. The requirements for joint spacing and slab reinforcement should be established by the designer based on experience and the intended slab use. A minimum 4 inch layer of free-draining gravel should be placed beneath basement level slabs to facilitate drainage. 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. All fill materials for support of floor slabs should be compacted to at least 95 % of maximum standard Proctor density at a moisture content near optimum. Required fill can consist of the on-site soils devoid of vegetation, topsoil and oversized rock. Underdrain System: Although free water was not encountered during our exploration, it has been our experience in the area that local perched groundwater can develop during times of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can create a perched condition. We recommend below-grade construction, such as retaining walls, crawlspace and basement areas, be protected from wetting and hydrostatic pressure buildup by an underdrain system. The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above the invert level with free-draining granular material. The drain should be placed at each level of excavation and at least 1 foot below lowest adjacent finish grade and sloped at a minimum 1 % to a suitable gravity outlet. Free-draining granular material used in the underdrain system should contain less than 2 % passing the No. 200 sieve, less than 50% passing the No. 4 sieve and have a maximum size of 2 inches. The drain gravel backfill should be at least 1 V2 feet deep. An impervious membrane such as 20 mil PVC should be placed beneath the drain gravel in a trough shape and attached to the foundation wall with mastic to prevent wetting of the bearing soils. Surface Drainage: The following drainage precautions should be observed during construction and maintained at all times after the residence has been completed: 1) Inundation of the foundation excavations and underslab areas should be avoided during construction. 2) Exterior backfill should be adjusted to near optimum moisture and H-P GEOTECH , . ; Bob Deherrera April 25, 2001 Page4 compacted to at least 95 % of the maximum standard Proctor density in pavement and slab 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 feet of the on-site, finer graded 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 recommend a minimum slope of 12 inches in the frrst 10 feet in unpaved areas and a minimum slope of 3 inches in the first 10 feet in pavement and walkway areas. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. 5) Landscaping which requires regular heavy irrigation should be located at least 10 feet from the building. Consideration should be given to the use of xeriscape to limit potential wetting due to irrigation. Percolation Testing: Percolation tests were conducted on April 17, 2001 to evaluate the feasibility of an infiltration septic disposal system at the site. One profile pit and three percolation holes were dug at the locations shown on Fig. 1. The test holes (nominal 12 inch diameter by 12 inch deep) were hand dug at the bottom of shallow backhoe pits on April 13, 2001 and were soaked with water on April 16, 2001, one day prior to testing. The soils exposed in the percolation holes are similar to those exposed in the Profile Pit shown on Fig. 2 and consist of about 21h feet of topsoil overlying medium stiff to stiff sandy clayey silt to the pit depth of 8 feet. No free water was encountered in the Profile Pit. The percolation test results are presented in Table II. The percolation test results indicate an infiltration rate between 11 and 30 minutes per inch with an average of 21 minutes per inch. Limitations: This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either expressed or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory pits excavated at the locations indicated on Fig. 1, the proposed type of construction and our experience in the area. Our findings include interpolation and extrapolation of the subsurface conditions identified at the exploratory pits and variations in the subsurface conditions H-P GEOTECH Bob Deherrera April 25, 2001 Page 5 may not become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report, we should be notified at once so re-evaluation of the recommendations may be made. This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during construction to review and monitor the implementation of our recommendations, and to verify that the recommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to the recommendations presented herein. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. If you have any questions or if we may be of further assistance, please let us know. Sincerely, Jordy Z. Adamson Reviewed by: Daniel E. Hardin, P.E. JZA/ksw attachments H-P GEOTECH ( 5970 I f-; I // I PIT 1 \ I ., I I I I I I I I PIT 2 I • I I I I I I LOT 55 I I I LOT 56 l I I I '/ P-1 4 PROFILE ) PIT P-31 : • '7'( I P-2 I I !::, I I I I I I I I I I / 5970 PROPERTY BOUNDARY-- I 1 I /i / BUILDING / / ENVELOPE // I I I I I I ) 5960 / : I I ROBERTSON . DITCH z ) APPROXIMA iE SCALE 1· = 50' 101 299 HEPWORTH-PAWLAK GEOTECHNICAL, INC. LOCATlON OF EXPLORATORY PITS Fig. 1 -.. ., .... .c. -Q. ., Q 0 5 10 LEGEND: PIT .1 ELEV.= 5967' WC-4.3 00=76 -200=76 LI.•22 PJ-3 WC-4.4 00=96 PIT 2 PIT 3 ELEV.= 5965' ELEV.= 5963' WC-4.6 00=92 -200=74 TOPSOIL; sandy clayey silt, organic, firm, slightly moist, dark brown. Root zone with soil similar to moterial below. SILT (ML); clayey sandy, medium stiff to stiff, slightly moist, brown. 2" Diameter hand driven liner sample. Disturbed bulk sample. NOTES: 1. Exploratory pits were excavated on April 13, 2001 with a CAT 4168 backhoe. 0 5 10 2. Locations of exploratory pits were measured approximately by pacing from features an the site plan provided. 3. Elevations of the exploratory pits were obtained by interpolation between contours on the site plan provided. logs are drawn to depth. 4. The exploratory pit 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 pit logs represent the approximate boundaries between material types ond transitions may be gradual. 6. No free water was encountered in the pits at the time of excavating. Fluctuations Tn water level may occur with time. 7. Laboratory Testing Results: WC = Water Content ( 3 ) DD = Dry Density ( pcf ) -200 = Percent passing No. 200 sieve LL = Liquid Limit ( 3 ) Pl = Plasticity Index ( 3 ) 101 299 HEPWORTH-PAWLAK GEDTECHNICAL. INC. LOGS OF EXPLORATORY PITS Fig. 2 -., .. ..... .c. -Q. .. 0 .. . . Moisture Content = 4.4 percent Dry Density = 96 pcf Sample ot Sandy Clayey Silt From: Pit 1 at 5.5 Feet 0 J_......-..... ,.Compression ~ r/ upon 1 wetting ~ c: "- 0 2 -a; II> "' ., "~ ... a. E 3 0 (.) ~ 4 5 0.1 1.0 10 100 APPLIED PRESSURE -ksf 101 299 HEPWORTH-PAWLAK SWELL CONSOLIDATION TEST RESULTS Fig. 3 GEOTECHNICAL, INC. . -• . . Moisture Content = 4.6 percent Dry Density = 92 pcf Sample of: Sandy Clayey Silt From: Pit 2 at 4.5 Feet 0 1 .._ ---2 ---, Compression \ up an 3 wetting \ "' 4 c \ 0 Oi VI .. 5 ... a. \ E 0 (.) 6 \ 7 8 \ 9 \ ' 10 o. 1 1.0 10 100 APPLIED PRESSURE -ksf 101 299 HEPWORTH-PAWLAK SWELL CONSOLIDATION TEST RESULTS Fig. 4 GEOTECHNICAL, INC. HEPWORTH-PAWLAK GEOTECHNICAL, INC. TABLE I JOB NO. 101 290 SUMMARY OF LABORATORY TEST RESULTS SAMPLE LOCATION NATURAL NATURAL GRADATION PERCENT ATTERBERG LIMITS UNCONFINED PIT DEPTH MOISlUAE ORV GRAVEL SANO PASSING LIQUID PLASTIC COMPRESSIVE SOIL OR !feet) CONTENT DENSITY , ... , , ... , NO. 200 LIMIT INDEX STRENGTH BEDROCK TYPE "'" lpclJ SIEVE , ... , , ... , IPSFI 1 4y, - 5 4.3 76 22 3 Sandy Clayey Silt 5 y, 4.4 96 Sandy Clayey Silt 2 4 y, 4.6 92 74 Sandy Clayey Silt HEPWORTH-PAWLAK GEOTECHNICAL, INC. TABLE II PERCOLATION TEST RESULTS JOBNO. 101 299 HOLE NO. HOLE DEPTH LENGTH OF WATER DEPTH WATER DEPTH DROP IN AVERAGE (INCHES! INTERVAL AT START OF AT END OF WATER PERCOLATION (MINI INTERVAL INTERVAL LEVEL RATE (INCHES! '(INCHES! UN CHES I (MIN.llNCHJ P-1 39 15 9 7 14 1 % 7% 5% 1 % watlll' added 9 7% 1 % 7% 6 14 1 y, 6 14 4% 1 y, 4% 3 y, 1 14 11 P-2 35 15 8 6% 1 % 6 'A 6 'A water added 7 14 6 y, 'A 6 y, 5 'A 'A 5 'A 5 'A .. 5 4% y, 23 P-3 51 15 8 7 14 'A 7 14 6 'A y, 6 'A 6 14 y, 6% 5% y, 5 'A 5% y, 5 14 4 'A y, 30 Note: Percolation test holes were hand dug in the bottom of backhoe pits on April 1 3, 2001 and soaked on April 1 6, 2001 . Percolation tests were conducted on April 1 7, 2001 . The average percolation rates were based on the last three readings of each test. NOTE: SETBACK FROM HOUSE TO TANK= 5 FT. MIN. PROPOSED RESIDENCE SETBACK FROM HOUSE TO TRENCH• 25 FT. MIN. ..,_ __ 4• DIA. ASTM 2729 PVC PIPE AT 114"/FT. SLOPE DISTRIBUTION LATERALS • _ ~ 4" DIA. ASTM 2729 PVC PIPE 14---SEPTlCTANK ./'//I AT114"1FT.SLOPE . ./"' HEADER PIPE~ 4" OIA. ASTM 2729 PVC AT 0% SLOPE (IE., FLAT) NOTE: INSTEAD OF INSTAWNG THE HEADER PIPE. THE CONTRACTOR MAY ./" ./ NOTE: AL THOUGH NOT REQUIRED. INSTAU.AllON OF INSPECTION PORTS AT THE BEGINNING OF EACH DISTRIBUTION LATERAL IS RECOMM- ENDED. OPT TO PLUMB EACH PIPE TO INF. TRENCH DIRECTLY FROM THE SEPTIC TANK.) ' '----~=====-ti~" USE EQUAL# OF INFILT. • UNITS PER TRENCH INSTALL 4" DIA. ~:rt::::::::::=::±t----4. VENTS (1 PER '-, TRENCHATTHE ---- END OF INFILTRATOR RUN(S) 1 • 10' MIN. ..r 10' MIN. .. 1 (TRENCHES TO BE LAID FLAT ANO PARNAl.ul Fl:i. TO SLOPE.) CENTER OF CENTER OF CENTER OF TRENCH TRENCH TRENCH NIJ"f&,' S~f f~~11~;,::~~~~~;ftt.°r~r"~ s 1'/l6fllt:.He.-. ,. ,,,., f~/2 rJeeft/CH fl.Gtttltllt£-O. SCHEMATIC PLAN VIEW OF SEPTIC SYSTEM INSTALLATION - -... .--~· _., 6 SCHMUESER I GORDON I MEYER ENGINEERS & SURVEYORS August 14, 2001 Mr. Bob DeHerrera 2902 Glen Avenue Glenwood Springs CO 81601 GLENWOOD SPRINGS I I 8 W. 6TH, SUITE 200 GLENWOOD SPRINGS, CO 8 I 60 I 970-945-1 004 FX: 970-945-5948 RE: Individual Sewage Disposal System (ISDS) Report Proposed Residence, Lot 56, Westbank Mesa Ranch Garfield County, Colorado Dear Bob: ASPEN P.O. BOX 2 I 55 ASPEN, CO 8 I 6 I 2 970-925-6727 FX: 970-925-4 I 57 Per your request, Schmueser Gordon Meyer has evaluated the design of the proposed septic system to service the residential flows from the proposed residence located at Lot 56, Westbank Mesa Ranch in Garfield County, Colorado. Based upon review of your drawings, we understand that the design of the individual sewage disposal system will be designed for a five-bedroom home. H-P Geotech has conducted an on-site soils investigation, i.e., percolation test), and we have attached the results hereto. H-P Geotech has identified the percolation rate for this property to range from 11 to 30 minutes per inch. The soils investigation did not identify the presence of groundwater or bedrock within the upper eight feet of soil at the site of the disposal field. A summary of the observed soil types identified that the septic system (or leach field system) is to be installed in medium stiff to stiff clayey silt. Based upon percolation test results and the soil observations, it appears that a standard leach field system can be installed on this site. This, of course, assumes that setback requirements can be met in accordance to Colorado State Health Department regulations. Accordingly, we have attached a table from the Colorado Department of Public Health & Environment ISDS regulations, which identify the required setbacks for each component of the septic system installed. The proposal for this site as far as method of disposal considers the use of a standard "infiltrator" system. This system, as proposed, will be installed in a trench-type fashion. Accordingly, we have attached manufacturer's product information regarding the infiltrator and the infiltrator system installation. To briefly describe the septic system as a whole, it is proposed to collect the effluent from the main waste line from the house to a 1500-gallon septic tank. Please note that this 1500-gallon concrete septic tank does have alternative installations available. Alternative installations may be considered, since no evidence of high groundwater is present. An alternative installation that may be considered with this type of system is a fiberglass septic tank with a capacity of 1500 gallons. We have not provided information as to a specified manufacturer or product line for fiberglass septic tanks. August14,2001 Mr. Bob De Herrera Page2 Please note that the septic tank must be located at least five feet away from the residence. In addition, the effluent line leaving the house and going to the septic tank must be straight in alignment and straight in grade. If it is deemed necessary that a change in alignment and/or grade in this main line from the house to the septic tank is required, a cleanout will be necessary to accompany the installation. This main line coming from the house to the septic tank must be a minimum 4" diameter. The grade of the pipe must be a minimum of Y." per foot. If it becomes necessary that a main line must cross a traveled area (i.e., vehicular access), we would then recommend that the pipe specifications be increased in strength, use Schedule 40 PVC in place of the ASTM 2729 designation. To compensate for differential settling between the septic tank and the incoming and outgoing piping, we would recommend that, through the zone of backfill for the tank, the piping coming into and leaving the septic tank be sleeved in a 6" diameter cast iron or Schedule 40 PVC. Once the effluent line leaves the septic tank, it will need to proceed towards the infiltrator trench system at a Y." per foot grade. Again, the minimum diameter of this pipe would need to be 4". We would recommend that, from this point to the infiltrator system, location of the infiltrator system and piping be situated such that no vehicular access is allowed over the piping or the infiltrator system. Additionally, with this recommendation, we would then maintain that the ASTM 2729 PVC piping be utilized. For the disposal system itself, we would recommend that a minimum of four standard infiltrator trenches be installed. We have attached our calculations, which define the length of infiltrator trench necessary, as well as the number of infiltrator units necessary per trench. The closest spacing that the infiltrator units can be installed is 10 feet on center. It is imperative for the proper function of the system that, the infiltrator units be placed in a flat, level trench. We have attached a sketch, which identifies the typical piping requirements to equally distribute flow to each of the infiltrator trenches. As previously discussed, we have attached the manufacturer's literature regarding the infiltrator system. With the manufacturer's literature, is a detailed list of instructions regarding installation of the septic system. You will note that the backfill required over an infiltrator trench is native backfill. This native backfill is acceptable for fill over the trenches as long as 6" and larger rock is not allowed in the backfill. The minimum requirement of 12" of cover over the infiltrator system is also identified. Please note that the infiltrator must be installed in an excavated trench, not in fill. The bottom of trench shall be into the soils 4-5 feet to take advantage of the design percolation rate of 25 mpi. The maximum final depth of the system is 42"; therefore, grading to remove overburden must be done above the system. As mentioned throughout this report, a number of attachments are included with this report. Please find the following list, which identifies specifically the attachments in order: 1. Calculations of leach field and septic system sizing. 2. Table of minimum horizontal setbacks. 3. Percolation test results. August 14, 2001 Mr. Bob DeHerrera Page 3 4. Schematic plan view of septic system installation. 5. Infiltrator manufacturer's product catalog. 6. Infiltrator manufacturer's Installation Instructions. 7. Septic system installation instructions (from Infiltrator manufacturer literature). Some general notes that must be mentioned regarding any septic system installation are as follows: 1. 2. 3. 4. 5. 6. 7. 8. All materials, installation practices and setback requirements shall comply with Garfield County Individual Sewage System Regulations. The infiltrator trench shall be constructed so that the bottom of the trench is level ± 0.1 foot. Place trench in natural !lround, no portion of the trench shall be placed in fill. Once backfilled, provide positive drainage way from the trenches. The area, disturbed by construction, shall be reseeded by native grasses to prevent erosion. Use risers as needed to bring septic tank access hatches within 6" of finish grade. Locate septic tank such that the access to the tanks can be accommodated for future pumping. The Contractor and Owner shall take whatever measures are necessary to assure that (a) the septic tank and sewerlines are completely watertight to prevent infiltration of groundwater in the system, and (b) the system is installed to prevent freezing of the gravity sewer1ines. No irrigation to be allowed over trenches. The Engineer and Garfield County Sanitation Department shall be notified when construction commences and kept abreast of the construction progress so that sufficient inspections can be performed to assure conformance with this report. It is the Contractor's responsibility to verify all locations of utilities and setbacks that may be affected by the installation of the septic system. Verification of all utility locations shall be made with the appropriate utility company. 9. Substitution of materials (i.e., pipe, tanks, etc.) is acceptable, provided verification and acceptance by the Engineer and the Garfield County Sanitation Department is made. August 14, 2001 Mr. Bob DeHerrera Page4 As you can gather from reading this report, we are leaving the specifics (i.e., exact location, grades and elevations) of the installation of the system to the Contractor and/or yourself. It is important to note, however, that the location of the septic system must be provided in the same general location of that identified with the boring logs of H-P Geotech. In essence, if the septic system is located on a site different than where the percolation test was taken, verification of the percolation rates must be made by H-P Geotech or SGM prior to final installation of the leach field. If it is determined that the information as provided is not of sufficient detail for your Contractor and/or yourself to construct the system, please notify us immediately and we can provide a detailed construction plan for the system. To accommodate such a detailed construction plan, SGM would have to coordinate with you, to collect detailed topography in the area of the proposed septic system. Aside from the comments just made, I hope this information is of sufficient detail to accommodate your needs in installing this septic system. If you have any questions or comments, please call. Sincerely, SCHMUESER GORDON MEYER, INC. (}1121 fi;Jjlr ,@ Clay Goldberg, P.E. 1:\2001-224\2001-224.isds.doc File: 2001-224.001 Enclosures ..... August14,2001 Mr. Bob DeHerrera Page 5 INDIVIDUAL SEWAGE DISPOSAL CALCULATIONS FOR PROPOSED DEHERRERA RESIDENCE, LOT 56, WESTBANK MESA RANCH GARFIELD COUNTY, COLORADO 1. Determine flows: 5-bedrooms in proposed residence 2 persons/bedroom 75 gpd/person Total average daily flow= (5)(2)(75) = 750 gpd 2. From H-P Geotech report: Percolation rate for design 25.0 mpi 3. Required septic tank capacity: For a 5-bedroom home= 1500 gallons 4. Determine field area: For absorption: Where A = field area Q =flow rate T = percolation A = [(Q)SqRt(T)] + 5 A = [(750)SqRt(25.0)] + 5 A= 750 SF 5. Peak flow at 150% per Colorado Department of Public Health & Environment Regulations and adjust field size accordingly. 1 .5 x 750 SF = 1125 SF 6. Areal adjustment to bed size for use of infiltrator. Decrease area by a factor of 50% A= 1125 x 0.5 = 562.5 SF 7. Areal adjustment to bed size for washer. (Factor by 1.4) and garbage disposal (Factor by 1.2) A = 562.5 x 1.4 x 1.2= 945 SF August14,2001 Mr. Bob DeHerrera Page6 8. Determine number of standard infiltrator units. Actual area per unit = 3' x 6.25'= 18.75 SF/unit, Allowable Area= 15.5 SF/unit 1890 SF+ 15.5 SF/unit= 61 units (Use 64 =4 x 16) Install 16 standard infiltrator units per trench in a four (4 )-trench configuration. 16 standard infiltrator units@ 6.25 feet per unit= 100 feet= maximum allowed length. 2001-224.001 8-01 ~ .. l'\,, ;,:,< .... tit ' '' TABLE or HINIHUH llORIZOll'fAL DISTANCES IN FEET BETWEEN COMPONENTS OF A SEWAGE DISPOSAL SYSTEM INSTALLED AFTER NOVEMBER 15, 1!173, A/Ill PER'l'HIEUT PHYSICAL FEATURES ;.tuper11al Syat.im i!: ilizing Aerosol tlathoda So!llJ>illlC Pi L or Sll t :·r1mch Spring, Walla, Suction Linf!o ••• 100 u• 100 Potable Watl!r Supply t.ine 10 so Potable Water Supply Ciotern 50 25 Dwell i I•.,, Occup1. 1 Puil d I u ,. ==""--··"' l.25 20 l'L·opcrty . _.!:!n.!.! 10 25 ·------------------------------· ,. .. qit!on Trench, Seepase : . .:d, Sand t'Uter, or Sub- .. '1C'focc: Dispersal System 1.llno?d Sand Filter 1n "11 IH th a Percolation ; .. 11co? Slower than 60 !-!tnutcu per Inch ·'' ''"'" or l';inlally Lined .. :vapocr11noplratJon System :::i:Jtewaccr Pond, or Surface ill:.;pou:il Sruteti uthcr than Aerosol Lined Sand l'L°lter J.lncd ~apotranep1rat1on Field or Lined Wastewater i'<>nj i'lL Privy or Vault Ptivy or Vault *** 100 100 100 60 60 50 25 25 25 10 10 10 25 25 25 25 25 25 20 10 15 10 15 10 15 10 15 10 l.5 .10 -CONTINUED, FOLLOWING PAGE - Subuoil Drain a 0 10 10 10 10 10 10 10 lake, Water Courot.!, lrrigatlon Ditch Dry Sep -~!_.§!:!:~!!!~1 _____ _!!~!!~!~~~ . .J~ • •• 25 ••• 50 ..... 50 25 25 25 25 :ZS " ... ~ ' l 10 ••• 25 ·---·--·--· . .. 25 15 ill• 15 I oJ 10 '"' . " I 1 ~ ; . t v l' j ' ., ... I. ... .. · .. • ' _.;• ~ :,:,l~ r.~:~· '!:!. 3c;•tlc Tanke, Treatment ;•t .:ntu, Poaing Tanke or ' i'! fluent Uoea I I I 11111 lJing Scwl!r I . . ·--~ ------·-- -CONTIHUEI> FROH PREVIOUS l'AGE - TABLE OF HIHIHUH llORIZOllTAL PIS'l'AJICES IH FEET BETWEEN COHPONEHTS OF A SEWAGE DISPOSAL SYSTEH INSTALLED AFTER HOVEHBER lS, 1973, AHD PERTillEllT PHYSICAL FEATURES Spriag, Potable Potable Lake, lfell1, Water· Water Dlfelliag, Ila ter Course, Suctioo Supply Supply ·Occupied Property Subaoil Irrigation Ditch ~ Dry Sep Linea Une Ci a tern Builc!ing Linea Drain a or Strc.?am Gulchcu Tank ** ** * •• ** ** •• ~· so 10 2.5 s 10 10 50 10 •. ** ** •• •• 50 10 2.5 0 0 10 50 10 -----------------·--·--- HOTEi lbe mioimu11 diataacea ahown above uhall be maintained between th" uystciu compooenta and the phyeicel features described, Where soil, geological or other conditiooa warrant, greater distance!' may be required by the local boar<! of heal Lt. o~ by the Water Quality Control Commission pursuant to C.R.S. 1973, 25-6-206 in accordance with the authority preacribeJ by law and rules and regulatlona lt1plcmcul of said aection. For repair or upgradin1: of existing ayotemo where tlrn ulze of Jot precludea adherence to theae diatancou, rl!paired facility ahall not be ~louer t<> water supply componentu than the exl.otl111; focilttiea, * Components which are not water 1.tght uliould not extend intp areaa of thu ru.>t system of nearby trees. Dietance shollD uhall not epply to treatment plants or effluent linea where recylcing is permitted. ** Crossings may ba permitted where pipelines are conatructed of auffictent etraagth to coataia' flove wadar preeeure. *** Add B'feet addit1oaal distance for each 100 gallona per day of deaisn flow over 1000 plloae par da1. •. 1