Loading...
HomeMy WebLinkAboutEngineer's Design Report 01.21.2019January 21, 2019 Mr. Andy Schwaller, Building Official Garfield County Building Department 108 8th Street Glenwood Springs, CO 81601 RE: Harbin OWTS 447 N. Meadows Drive Rifle, CO 81650 Dear Andy, SSGM www.sgm-inc.com The purpose of this letter is to provide you soils and design information relative to a tactile soils analysis that SGM has performed on behalf of Chad Harbin in support of the replacement of a failed OWTS at his home on 447 N. Meadows Drive, Rifle, Colorado. The site sits north of Antonelli Lane and east of Miller Lane on Silt Mesa on a 2.01 acre parcel in the NW 1/4 of Section 5, T6S, Range 92 W. The currently failed OWTS serves a 3 bedroom single family residence. From our on-site tactile soils testing, site reconnaissance of the property and review of original OWTS design permit, the older failed system was a 1,000 gallon septic tank followed by a Infiltrator Quick4 bed system consisting of 26 units. The following figure identifies the location of the property from the County's GIS website. Search Sea ah PLSS liawnship. Range. Section . Sub6wion Buller Draw Layers Measure Locale . Ba9emap Copy) Search CSV) Results PDF Print Taal • Preece. Addles 21)805022119 408kS001eS wR66.1 CIAO OR 8212 206911 .wsve l to dlwe* Previous Next 5.1 11 odow 21 1.40 11177 1119 20'201, x 1,7, 71Dears $1. ©Nes 9110 Maori ROII2A. Owner HAR91N, CHAD ROBERT Plrydod Address W2 N MEADOWS DR EIRE 81650 wiling Address N) N MEADOW O8VE RIFLE CC 81650 Aeras 2 2017 MN Levy 66.0000 Figure 1- Site Location GLENWOOD SPRINGS 118 West Sixth St, Suite 200 1 Glenwood Springs, CO 81601 1 970.945.1004 6SGM www.sgm-inc.com From the NRCS Websoil Survey, the on-site soils (for the STA) are identified as a Potts loam. The on-site observations of the Potts loam were characteristic of the clay loam identified in the WebSoil Survey. We have attached a soil report from the NRCS Websoil Survey to describe further the expected characteristics of the soils determined through our pre -site investigation. Our findings of the soil concur with those characteristics identified by NRCS in their soil investigation for the Websoil information. Specifically, our findings are as follows: 1. Depth to ground water is greater than 8 feet. 2. Depth to limiting layer (ie., ground water or bedrock) is greater than 8 feet. 3. Other than a limited depth of topsoil, the soil horizon(s) below the topsoil is a consistent clay loam soil meeting the characteristics of the Soil Type 3A in Table 10-1 of Regulation 43 from CDPHE. 4. The soil structure grade was a moderate structure with approximately 50% peds found. 5. The No. 10 sieve and smaller particles had a blocky/granular soil structure. 6. The sample contained less than 35% rock. 7. The ribbon size from tactile analysis revealed a 1-2 inch ribbon with a small amount of grit and a less than smooth texture. 8. Given these results, the classification for these soils is a Clay Loam, or as previously stated, a Type 3A Soil per Regulation 43 Table 10-1. (GARCO Table 10-1) 9. The depth of this soil layer exceeds 8 feet with no groundwater, bedrock nor other limiting layer encountered. Based upon our review of the county records for this site, the existing OWTS consisted of a 1000 gallon septic tank with gravity flow from the second compartment of the tank to an Infiltrator Quick4 bed system located south of the home. The system was originally sized for 3 bedrooms with a soils percolation rate noted as 6 minutes per inch. As noted, this is a replacement design for a failed system. Differing data now exists in our analysis which is noted as follows: • The bedroom count for the residence is three (3) bedrooms and an office, thus we are sizing the replacement STA for 4 bedrooms while leaving the septic tank at 3 bedrooms (ie., 1,000 gallon tank) • The soil tactile analysis reveals a Type 3A soil which is reflective of percolation rates of 61-75 mpi. The loading rate for the Type 3 soil and TL1 is 0.30 gallons/sf/day. • We are recommending constructing the replacement STA in the Potts clay loam located just south and east of the home. This will require a gravity system to infiltrator trenches. Gravity Trench System 6SGM www.sgm-inc.com As you will see on the schematic drawings for this alternative and the information attached, the home will need to utilize the existing 1,000 gallon septic tank. This existing tank is reflected as being a precast concrete tank (Copeland manufactured). From the septic tank, the effluent would then flow by gravity to the distribution box for the Soil Treatment Area (STA) which is proposed to be Infiltrator Quick4 chambers constructed in a trench format. A variety of bends and clean outs would need to be installed from the tanks to the distribution box. At the distribution box, we are recommending that Polylok flow distribution weirs be installed to assure equal effluent distribution to each of the six (6) infiltrator trenches. Each of the chambered trenches can be installed at a constant level (ie., 24 to 48" below grade) as equal flow distribution is being accomplished through the distribution box and weirs. There are to be 6 trenches with 20 chambers per trench provided. Standard end caps are proposed on the end of each trench along with inspection ports. The piping from the tank, distribution box and infiltrator trenches shall be a minimum diameter of 4" diameter ASTM 3034 PVC. The location of the tank, distribution box, gravity pipe route and infiltrator trenches will be specified in the attached drawing plan of this package. Note that the drawing package is prepared in a schematic format that relies on you to provide adequate grading to accomplish the intent of the design. In this manner, it is anticipated that you can provide routing modifications to make sure that the grading works for the site. Note that the component construction for the replacement system will need to follow the requirements of Sections 43.8, 43.9 and 43.10 of regulation 43 (as adopted by Garfield County) for the tank, distribution box, piping and STA as applicable. We have attached a copy of each of these sections for reference by the contractor to assure each component construction is adequately addressed. Upon your receipt and review, if you have any questions, please don't hesitate to call. Respectfully, SGM Jef'e - S. Simonson, PE, CFM Principal OWTS Design Report and Calculations Client: Chad Harbin 447 N. Meadows Drive Rifle, CO 81650 Date: September 17,2019 Flow Data for the OWTS Design 1 Home Use (3 Bedroom Home) (sizing STA for 4 bedroom) Project Location: 600 Total= 600 Section 5 Township 6S Range 92W For Home Use, 2 persons per bedroom and 75 gallons per day per person, BOD5 = 0.06 #/person/day Home Use Totals: Soil Data for the OWTS 600 gpd 0.48 #/day 600 gpd 0.48 #/day 2 Data from on-site soil observations: Appears to be a clay loam soil of consistent depth from surface beyond a depth of 8 feet where the depth of the profile pits were excavated. At a depth of 8', neither bedrock or groundwater have been encountered. Data from the web soil survey indicates an Potts Clay Loam exists. Average of 3 percolation holes: N/A mpi (Soil Tactile Analysis Perfomed) Given the consideration of all data, the Long Term Acceptance Rate to use is 0.30 gallons/sf/day Septic Tank Sizing 3 Flow calculated from above: 48 hour detention time for septic tank sizing; 600 gpd Volume= 1200 gpd Maintain 1,000 gallon tank. (Sizing STA for 4 BR, House is 3 BR per County records) Dosing Tank Sizing 4 Flow calculated from above: Dose rate is ADF/4: Go with 600 gpd 150 gpd 250 gallon dosing tank (if applicable) Sizing of Absorption Field or Soil Treatment Area 5 Going with a soil type 3A and Treatment Level 1, LTAR = 0.3 g/sf/d For a pressure dosed system, size adjustment factor is 1.0 for a bed configuration For a gravity system, the size adjustment factor shall be 1.2 for a bed configuration For a gravity trench system, adjustment factor = 1.0 For a siphon or pump dosed system, adjustment factor= 0.9 For a pressure dosed trench system, adjustment factor = 0.8 For use of chambers: size adustment factor is 0.7 STA= Flow/LTAR 2000 square feet (unfactored) For a chamber system, gravity flow, adjust size to 0.7*2000= Incorporating a pressure dosed system, adjust size to 0.8*1400= Incorporation a siphon or pump dosed system adjust size to 0.9*1400= For a pressure dosed chamber system in a trench configuration, length= (this would equate to 5 runs of 75 feet each) For a siphon or pump dosed chamber system in trench config, length= (this would equate to 5 runs of 84 feet each) 1400 square feet 1120 square feet 1260 square feet 373 feet 420 feet For a gravity chamber system in a trench configuration, length= 466.67 feet (this would equate to 6 runs of 80 feet each) Alternate 1: n/a Alternate 2: n/a Alternate 3: Gravity flow trench system: Use 20 Quick4 chambers in each of 6 trenches (80' per trench) USDA United States Department of Agr culture RCS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Rifle Area, Colorado, Parts of Garfield and Mesa Counties Harbin OWTS January 21, 2019 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nres) or your NRCS State Soil Scientist (http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface 2 Soil Map 5 Soil Map (Harbin OWTS) 6 Legend 7 Map Unit Legend (Harbin OWTS) 9 Map Unit Descriptions (Harbin OWTS) 9 Rifle Area, Colorado, Parts of Garfield and Mesa Counties 11 55—Potts loam, 3 to 6 percent slopes 11 Soil Information for All Uses 12 Soil Reports 12 Soil Physical Properties 12 Engineering Properties (Harbin OWTS) 12 Physical Soil Properties (Harbin OWTS) 16 4 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 5 39° 33' 30" N 8 r 8 r 8 r 8 r 8 r 39° 33'26"N 8 268660 268660 268700 268720 Custom Soil Resource Report Soil Map (Harbin OWTS) 268740 268760 268780 26 200 268820 268840 8 Soil Map may not be valid at this scale. 268660 NA 268680 268700 268720 Map Scale: 1:892 if printed on A landscape (11" x 8.5") sheet. 0 10 20 40 Meters 60 268740 0 40 80 Feet 160 240 Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 6 268760 268780 268800 268820 268840 8 8 8 39° 33' 30" N 39° 33' 26" N Custom Soil Resource Report Area of Interest (AOI) Soils 0 Soil Map Unit Lines MAP LEGEND Area of Interest (AOI) Soil Map Unit Polygons Soil Map Unit Points Special Point Features Blowout la Borrow Pit Clay Spot • Closed Depression • Gravel Pit Gravelly Spot • Landfill Lava Flow Marsh or swamp an4 Mine or Quarry • Miscellaneous Water • Perennial Water • Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip oa Sodic Spot A Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation 1 _F Rails 0.10 Interstate Highways wrapUS Routes Major Roads Local Roads Background 1. Aerial Photography 7 MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 11, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Dec 31, 2009—Oct 12, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background Custom Soil Resource Report MAP LEGEND MAP INFORMATION imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report Map Unit Legend (Harbin OWTS) Map Unit Descriptions (Harbin OWTS) The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. 9 Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 55 Totals for Area of Interest Potts loam, 3 to 6 percent slopes 2.3 2.3 100.0% 100.0% Map Unit Descriptions (Harbin OWTS) The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. 9 Custom Soil Resource Report An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha -Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 10 Custom Soil Resource Report Rifle Area, Colorado, Parts of Garfield and Mesa Counties 55—Potts loam, 3 to 6 percent slopes Map Unit Setting National map unit symbol: jnyr Elevation: 5,000 to 7,000 feet Farmland classification: Prime farmland if irrigated Map Unit Composition Potts and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Potts Setting Landform: Valley sides, benches, mesas Down-slope shape: Convex, linear Across -slope shape: Convex, linear Parent material: Alluvium derived from basalt and/or alluvium derived from sandstone and shale Typical profile H1 - 0 to 4 inches: loam H2 - 4 to 28 inches: clay loam H3 - 28 to 60 inches: loam Properties and qualities Slope: 3 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 10.3 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3c Hydrologic Soil Group: C Ecological site: Rolling Loam (R048AY298C0) Hydric soil rating: No 11 Soil Information for All Uses Soil Reports The Soil Reports section includes various formatted tabular and narrative reports (tables) containing data for each selected soil map unit and each component of each unit. No aggregation of data has occurred as is done in reports in the Soil Properties and Qualities and Suitabilities and Limitations sections. The reports contain soil interpretive information as well as basic soil properties and qualities. A description of each report (table) is included. Soil Physical Properties This folder contains a collection of tabular reports that present soil physical properties. The reports (tables) include all selected map units and components for each map unit. Soil physical properties are measured or inferred from direct observations in the field or laboratory. Examples of soil physical properties include percent clay, organic matter, saturated hydraulic conductivity, available water capacity, and bulk density. Engineering Properties (Harbin OWTS) This table gives the engineering classifications and the range of engineering properties for the layers of each soil in the survey area. Hydrologic soil group is a group of soils having similar runoff potential under similar storm and cover conditions. The criteria for determining Hydrologic soil group is found in the National Engineering Handbook, Chapter 7 issued May 2007(http:// directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=17757.wba). Listing HSGs by soil map unit component and not by soil series is a new concept for the engineers. Past engineering references contained lists of HSGs by soil series. Soil series are continually being defined and redefined, and the list of soil series names changes so frequently as to make the task of maintaining a single national list virtually impossible. Therefore, the criteria is now used to calculate the HSG using the component soil properties and no such national series lists will be maintained. All such references are obsolete and their use should be discontinued. Soil properties that influence runoff potential are those that influence the minimum rate of infiltration for a bare soil after prolonged wetting and when not frozen. These properties are depth to a seasonal high water table, saturated hydraulic conductivity after prolonged wetting, and depth to a layer with a very slow water transmission 12 Custom Soil Resource Report rate. Changes in soil properties caused by land management or climate changes also cause the hydrologic soil group to change. The influence of ground cover is treated independently. There are four hydrologic soil groups, A, B, C, and D, and three dual groups, A/D, B/D, and C/D. In the dual groups, the first letter is for drained areas and the second letter is for undrained areas. The four hydrologic soil groups are described in the following paragraphs: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. Depth to the upper and lower boundaries of each layer is indicated. Texture is given in the standard terms used by the U.S. Department of Agriculture. These terms are defined according to percentages of sand, silt, and clay in the fraction of the soil that is less than 2 millimeters in diameter. "Loam," for example, is soil that is 7 to 27 percent clay, 28 to 50 percent silt, and less than 52 percent sand. If the content of particles coarser than sand is 15 percent or more, an appropriate modifier is added, for example, "gravelly." Classification of the soils is determined according to the Unified soil classification system (ASTM, 2005) and the system adopted by the American Association of State Highway and Transportation Officials (AASHTO, 2004). The Unified system classifies soils according to properties that affect their use as construction material. Soils are classified according to particle -size distribution of the fraction less than 3 inches in diameter and according to plasticity index, liquid limit, and organic matter content. Sandy and gravelly soils are identified as GW, GP, GM, GC, SW, SP, SM, and SC; silty and clayey soils as ML, CL, OL, MH, CH, and OH; and highly organic soils as PT. Soils exhibiting engineering properties of two groups can have a dual classification, for example, CL -ML. The AASHTO system classifies soils according to those properties that affect roadway construction and maintenance. In this system, the fraction of a mineral soil that is less than 3 inches in diameter is classified in one of seven groups from A-1 through A-7 on the basis of particle -size distribution, liquid limit, and plasticity index. Soils in group A-1 are coarse grained and low in content of fines (silt and clay). At the other extreme, soils in group A-7 are fine grained. Highly organic soils are classified in group A-8 on the basis of visual inspection. If laboratory data are available, the A-1, A-2, and A-7 groups are further classified as A -1-a, A -1-b, A-2-4, A-2-5, A-2-6, A-2-7, A-7-5, or A-7-6. As an additional refinement, the suitability of a soil as subgrade material can be indicated by a group 13 Custom Soil Resource Report index number. Group index numbers range from 0 for the best subgrade material to 20 or higher for the poorest. Percentage of rock fragments larger than 10 inches in diameter and 3 to 10 inches in diameter are indicated as a percentage of the total soil on a dry -weight basis. The percentages are estimates determined mainly by converting volume percentage in the field to weight percentage. Three values are provided to identify the expected Low (L), Representative Value (R), and High (H). Percentage (of soil particles) passing designated sieves is the percentage of the soil fraction less than 3 inches in diameter based on an ovendry weight. The sieves, numbers 4, 10, 40, and 200 (USA Standard Series), have openings of 4.76, 2.00, 0.420, and 0.074 millimeters, respectively. Estimates are based on laboratory tests of soils sampled in the survey area and in nearby areas and on estimates made in the field. Three values are provided to identify the expected Low (L), Representative Value (R), and High (H). Liquid limit and plasticity index (Atterberg limits) indicate the plasticity characteristics of a soil. The estimates are based on test data from the survey area or from nearby areas and on field examination. Three values are provided to identify the expected Low (L), Representative Value (R), and High (H). References: American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. 14 Custom Soil Resource Report Absence of an entry indicates that the data were not estimated. The asterisk'*' denotes the representative texture; other possible textures follow the dash. The criteria for determining the hydrologic soil group for individual soil components is found in the National Engineering Handbook, Chapter 7 issued May 2007(http://directives.sc.egov.usda.gov/ OpenNonWebContent.aspx?content=17757.wba). Three values are provided to identify the expected Low (L), Representative Value (R), and High (H). Engineering Properties–Rifle Area, Colorado, Parts of Garfield and Mesa Counties Map unit symbol and soil name Pct. of map unit Hydrolo gic group Depth USDA texture Classification Pct Fragments Percentage passing sieve number— Liquid limit Plasticit y index Unified AASHTO >10 inches 3-10 inches 4 10 40 200 In L -R -H L -R -H L -R -H L -R -H L -R -H L -R -H L -R -H L -R -H 55—Potts loam, 3 to 6 percent slopes Potts 85 C 0-4 Loam CL, CL- A-4 ML 0- 0- 0 0- 0- 0 100-100 -100 100-100 -100 85-90- 95 60-68- 75 25-28 -30 5-8 -10 4-28 Clay loam CL A-6 0- 0- 0 0- 0- 0 100-100 -100 100-100 -100 90-95-1 00 70-75- 80 30-35 -40 10-15-2 0 28-60 Loam CL, CL- A-4 ML 0- 0- 0 0- 0- 0 100-100 -100 100-100 -100 85-90- 95 60-68- 75 25-28 -30 5-8 -10 15 Custom Soil Resource Report Physical Soil Properties (Harbin OWTS) This table shows estimates of some physical characteristics and features that affect soil behavior. These estimates are given for the layers of each soil in the survey area. The estimates are based on field observations and on test data for these and similar soils. Depth to the upper and lower boundaries of each layer is indicated. Particle size is the effective diameter of a soil particle as measured by sedimentation, sieving, or micrometric methods. Particle sizes are expressed as classes with specific effective diameter class limits. The broad classes are sand, silt, and clay, ranging from the larger to the smaller. Sand as a soil separate consists of mineral soil particles that are 0.05 millimeter to 2 millimeters in diameter. In this table, the estimated sand content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 millimeters in diameter. Silt as a soil separate consists of mineral soil particles that are 0.002 to 0.05 millimeter in diameter. In this table, the estimated silt content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 millimeters in diameter. Clay as a soil separate consists of mineral soil particles that are less than 0.002 millimeter in diameter. In this table, the estimated clay content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 millimeters in diameter. The content of sand, silt, and clay affects the physical behavior of a soil. Particle size is important for engineering and agronomic interpretations, for determination of soil hydrologic qualities, and for soil classification. The amount and kind of clay affect the fertility and physical condition of the soil and the ability of the soil to adsorb cations and to retain moisture. They influence shrink - swell potential, saturated hydraulic conductivity (Ksat), plasticity, the ease of soil dispersion, and other soil properties. The amount and kind of clay in a soil also affect tillage and earthmoving operations. Moist bulk density is the weight of soil (ovendry) per unit volume. Volume is measured when the soil is at field moisture capacity, that is, the moisture content at 1/3- or 1/10 -bar (33kPa or 10kPa) moisture tension. Weight is determined after the soil is dried at 105 degrees C. In the table, the estimated moist bulk density of each soil horizon is expressed in grams per cubic centimeter of soil material that is less than 2 millimeters in diameter. Bulk density data are used to compute linear extensibility, shrink -swell potential, available water capacity, total pore space, and other soil properties. The moist bulk density of a soil indicates the pore space available for water and roots. Depending on soil texture, a bulk density of more than 1.4 can restrict water storage and root penetration. Moist bulk density is influenced by texture, kind of clay, content of organic matter, and soil structure. Saturated hydraulic conductivity (Ksat) refers to the ease with which pores in a saturated soil transmit water. The estimates in the table are expressed in terms of micrometers per second. They are based on soil characteristics observed in the field, particularly structure, porosity, and texture. Saturated hydraulic conductivity (Ksat) is considered in the design of soil drainage systems and septic tank absorption fields. 16 Custom Soil Resource Report Available water capacity refers to the quantity of water that the soil is capable of storing for use by plants. The capacity for water storage is given in inches of water per inch of soil for each soil layer. The capacity varies, depending on soil properties that affect retention of water. The most important properties are the content of organic matter, soil texture, bulk density, and soil structure. Available water capacity is an important factor in the choice of plants or crops to be grown and in the design and management of irrigation systems. Available water capacity is not an estimate of the quantity of water actually available to plants at any given time. Linear extensibility refers to the change in length of an unconfined clod as moisture content is decreased from a moist to a dry state. It is an expression of the volume change between the water content of the clod at 1/3- or 1/10 -bar tension (33kPa or 10kPa tension) and oven dryness. The volume change is reported in the table as percent change for the whole soil. The amount and type of clay minerals in the soil influence volume change. Linear extensibility is used to determine the shrink -swell potential of soils. The shrink -swell potential is low if the soil has a linear extensibility of less than 3 percent; moderate if 3 to 6 percent; high if 6 to 9 percent; and very high if more than 9 percent. If the linear extensibility is more than 3, shrinking and swelling can cause damage to buildings, roads, and other structures and to plant roots. Special design commonly is needed. Organic matter is the plant and animal residue in the soil at various stages of decomposition. In this table, the estimated content of organic matter is expressed as a percentage, by weight, of the soil material that is less than 2 millimeters in diameter. The content of organic matter in a soil can be maintained by returning crop residue to the soil. Organic matter has a positive effect on available water capacity, water infiltration, soil organism activity, and tilth. It is a source of nitrogen and other nutrients for crops and soil organisms. Erosion factors are shown in the table as the K factor (Kw and Kf) and the T factor. Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by water. Factor K is one of six factors used in the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE) to predict the average annual rate of soil loss by sheet and rill erosion in tons per acre per year. The estimates are based primarily on percentage of silt, sand, and organic matter and on soil structure and Ksat. Values of K range from 0.02 to 0.69. Other factors being equal, the higher the value, the more susceptible the soil is to sheet and rill erosion by water. Erosion factor Kw indicates the erodibility of the whole soil. The estimates are modified by the presence of rock fragments. Erosion factor Kf indicates the erodibility of the fine -earth fraction, or the material less than 2 millimeters in size. Erosion factor T is an estimate of the maximum average annual rate of soil erosion by wind and/or water that can occur without affecting crop productivity over a sustained period. The rate is in tons per acre per year. Wind erodibility groups are made up of soils that have similar properties affecting their susceptibility to wind erosion in cultivated areas. The soils assigned to group 1 are the most susceptible to wind erosion, and those assigned to group 8 are the least susceptible. The groups are described in the "National Soil Survey Handbook." 17 Custom Soil Resource Report Wind erodibility index is a numerical value indicating the susceptibility of soil to wind erosion, or the tons per acre per year that can be expected to be lost to wind erosion. There is a close correlation between wind erosion and the texture of the surface layer, the size and durability of surface clods, rock fragments, organic matter, and a calcareous reaction. Soil moisture and frozen soil layers also influence wind erosion. Reference: United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430 -VI. (http://soils.usda.gov) 18 1111 EilaNtirA ' tiriI', Fi% Witt), RN Reception#: 848421 04122/2014 09.31 33 RM Jean Rlberico 45 of 80 Rec Fee $0 00 Doc Fee 0 00 GARFIELD COUNTY CO 43.8 Design Criteria — General Table 7-2 On-site Wastewater Treatment System Design Consideration and Treatment Requirements — Separation Distances from Soil Treatment Area NOTE: Treatment levels are defined in Table 6-3. Reductions in separation distances with higher level treatment may be granted only if the local public health agency regulations have included provisions for operation and maintenance. 1 Prior to approval, all setback distance reductions to the 100 foot requirement for wells and soil treatment areas must be in full compliance with the minimum standards and variance requirements of the State of Colorado Division of Water Resources: Rules and Regulations for Water Well Construction, Pump Installation, Cistern Installation, and Monitoring and Observation Hole/Well Construction. 43.8 Design Criteria — General A. Performance: OWTS shall be designed and constructed to achieve the treatment level specified by the design. B. Reliability: OWTS shall be designed and constructed such that each component shall function, when installed and operated, in a manner not adversely affected by normal operating conditions including erosion, corrosion, vibration, shock, climatic conditions, and usual household chemicals. Each component shall be free of non-functional protrusions or sharp edges, or other hazards, which could cause injury to persons, animals, or properties. Design shall be such as to exclude flies and rodents and other vectors and to prevent the creation of nuisances and public health hazards and shall provide for efficient operation and maintenance. 41 PRESSURE DOSING REQUIRED ITEM OWTS DESIGN CONSIDERATION Treatment Levels 1 and 2 Treatment Level 2N Treatment Level 3 Treatment Level 3N Horizontal Separation Distances 1 Distance from soil treatment area to on-site well Greater than or equal to 100 feet Greater than or equal to 100 feet Greater than or equal to 100 feet Greater than or equal to 75 feet' 2 Distance from soil treatment area to pond, creek, lake, or other surface water feature Greater than or equal to 50 feet Greater than or equal to 25 feet Greater than or equal to 25 feet Greater than or equal to 25 feet 3 Distance from soil treatment area to dry gulch or cut bank Greater than or equal to 25 feet Greater than or equal to 10 feet Greater than or equal to 10 feet Greater than or equal to 10 feet Vertical Separation Distances 4 Depth in feet from soil treatment area infiltrative surface to restrictive layer or ground water 4 feet (3 feet with pressure dosing) Greater than or equal to 2 feet Greater than or equal to 2 feet Greater than or equal to 2 feet NOTE: Treatment levels are defined in Table 6-3. Reductions in separation distances with higher level treatment may be granted only if the local public health agency regulations have included provisions for operation and maintenance. 1 Prior to approval, all setback distance reductions to the 100 foot requirement for wells and soil treatment areas must be in full compliance with the minimum standards and variance requirements of the State of Colorado Division of Water Resources: Rules and Regulations for Water Well Construction, Pump Installation, Cistern Installation, and Monitoring and Observation Hole/Well Construction. 43.8 Design Criteria — General A. Performance: OWTS shall be designed and constructed to achieve the treatment level specified by the design. B. Reliability: OWTS shall be designed and constructed such that each component shall function, when installed and operated, in a manner not adversely affected by normal operating conditions including erosion, corrosion, vibration, shock, climatic conditions, and usual household chemicals. Each component shall be free of non-functional protrusions or sharp edges, or other hazards, which could cause injury to persons, animals, or properties. Design shall be such as to exclude flies and rodents and other vectors and to prevent the creation of nuisances and public health hazards and shall provide for efficient operation and maintenance. 41 1111 MidCiiEMIN'1541 Ki NFIVIrIlle'1 110011rI'i, 1111 Reception#: 848421 04I22i2014 09 31:33 AM Jean Rlberico 48 of 90 Rec Fee•$0 00 Doc Fee:0 0C GRRFIEL_D COUNTY CO 43.8 Design Criteria — General C. Accessibility for Inspection, Maintenance, and Servicing 1. Septic tanks shall have risers over each access manhole and all risers shall extend to or above final grade. 2. Each treatment component of an OWTS other than the septic tank and soil treatment area shall be equipped with access manholes with risers that extend to or above final grade, located to permit periodic physical inspection, collection and testing of samples and maintenance of all components and compartments. 3. Riser Lids a. Each riser lid brought to the surface shall have a secure closing mechanism, such as a lock, special headed bolts or screws, or sufficient weight to prevent unauthorized access. b. A local public health agency may require a secondary plug, cap, cover or screen be provided below the riser cover to prevent tank entry if the cover is unknowingly damaged or removed. 4. Components that require access for maintenance shall include but not be limited to submerged bearings, moving parts, pumps, siphons, valves, tubes, intakes, slots, distribution boxes, drop boxes, cleanouts, effluent screens, filters, inlet and outlet baffles, aerators, treatment equipment and other devices. 5. Components shall be designed and constructed so that, when installed, they shall be easily maintained, sampled, and serviced according to the manufacturer's recommendations. Easy physical access to treatment components by maintenance personnel and equipment shall be provided. D. Plumbing Codes: Plumbing fixtures, building sewers, vents, sewer lines and other appurtenances shall be designed, operated and maintained so as to comply with the minimum requirements of the most recently revised locally enforceable plumbing code. In absence of a local plumbing code, designs shall adhere to the Colorado Plumbing Code (3 CCR 720-1). E. Electrical Equipment, If Used 1. All electrical work, equipment, and material shall comply with the requirements of the currently applicable National Electrical Code as designated by the State Electrical Board Rules and Regulations (3 CCR 710-1). A local State electrical permit may be required. 2. Electrical components shall be protected from moisture and corrosive gases. F Indicators of Failure or Malfunctioning for Systems Utilizing Mechanical Apparatus: A signal device shall be installed which will provide a recognizable indication or warning to the user that the system or component is not operating or is operating but malfunctioning. This indication or warning shall be a visual signal or an audible signal or both and shall be located in a centralized area within visual and audible range of the system user. A signal or message may also be sent remotely to a maintenance provider. 42 VIII ,irdFM:0111111.11 ,Mfi111151 1114qPiiiiiiSi11l is 11111 Reception#: 848421 0472212014 09:31-33 PM Jean Rlberico 47 of 80 Rec Fee $0.00 Doc Fee:0 00 GARFIELD COUNTY CO G. Sampling Access 43.8 Design Criteria — General 1. If sampling for testing or as a requirement for a permit will be required of effluent from a component other than the soil treatment area, an accessible sampling point shall be provided. 2. If sampling of the treated wastewater from the soil treatment area will be required for testing or as a requirement for a permit, a monitoring well or wells shall be constructed. Monitoring wells shall be located down gradient from the soil treatment area, accessible, and provided with a properly securable cover at or above the ground surface. Monitoring wells up gradient of the system may also be required. Lysimeters or other collection devices under the soil treatment area may be used instead of a monitoring well if approved by the local public health agency or other issuer of a permit. H. Component Operating Instructions 1. The manufacturer of proprietary treatment units utilizing mechanical components shall provide clear, concise written instructions covering the components which, when followed, shall assure proper installation and safe and satisfactory operation and maintenance. 2. If the OWTS uses public domain technology, the design engineer shall provide clear, concise written instructions covering the components which, when followed, shall assure proper installation and safe and satisfactory operation and maintenance. Surface Activity: Activity or use on the surface of the ground over any part of the OWTS must be restricted to that which shall allow the system to function as designed and which shall not contribute to compaction of the soil or to structural loading detrimental to the structural integrity or capability of the component to function as designed. During construction, equipment shall be kept off of the ground surface above the soil treatment area and out of the excavation to prevent compaction. If compaction occurs, the disturbed or compacted soil shall be re-evaluated and new percolation tests may be performed to the disturbed or compacted soil and the system redesigned if the parameters have changed. J. Floodplains 1. New OWTS and replacement OWTS installed in a 100 -year floodplain shall meet or exceed the requirements of the Federal Emergency Management Agency and the local emergency agency. Repairs of an existing system shall meet the requirements as feasible. The system as approved by a local public health agency shall be designed to minimize or eliminate infiltration of floodwaters into the system and discharge from the system into the floodwaters. 2. No new or expanded OWTS shall be installed in a floodway designated in a 100 -year floodplain. For any system repair that may affect the floodway delineation, appropriate procedures shall be followed including revision of the floodway designation, if necessary. K. Business Commercial, Industrial, Institutional or Multi -Family Dwelling Wastewater Systems 1. An OWTS that will serve a business, commercial, industrial or institutional property, or a multifamily dwelling shall: a. Be designed by a professional engineer; 43 11111 14!�� �IrLrN'II uP L�i��� �' I"�If I�,� �����1�� I>tiI i, 111 111 Reception#: 848421 04:2212014 09:31:33 RM Jean Rlberico ae of 80 Rec. Fee $0 00 Doc Fee 0 00 GRRFIELD COUNTY (:0 43.9 Design Criteria - Components b. Receive only such biodegradable wastes for treatment and distribution as are compatible with those biological treatment processes as occur within the septic tank, any additional treatment unit and the soil treatment area; and c. Receive authorization by rule or a class V underground injection permit from the United States Environmental Protection Agency (EPA) before an application for an OWTS permit is approved if the system may receive non-residential wastewater or is otherwise covered by the EPA underground injection control program. 43.9 Design Criteria - Components A. Tanks and Vaults 1. Watertightness a. Septic tanks, vaults, pump tanks, other treatment components, risers and lids shall not allow infiltration of ground water or surface water and shall not allow the release of wastewater or liquids through other than designed openings. b. Acceptable watertightness testing methods performed at a manufacturer's site or in the field include water filling the tank or vacuum testing. 2. Tank Anchoring: In locations where ground water or floodwaters may cause instability problems to the septic tank, vault, or other treatment unit in the OWTS due to flotation, the tank, vault or unit shall be anchored in a manner sufficient to provide stability when the tank is empty. Risers shall be included in the buoyancy calculations. a. If a manufacturer provides recommendations for anchoring designs, they may be used if they meet the conditions present at the site. b. If a manufacturer does not provide recommendations for provisions to compensate for buoyancy, or if the professional engineer chooses to provide his/her own designs, the anchoring system design shall be prepared by the professional engineer. 3. Identification and Data Marking: All tanks and treatment units shall be permanently and legibly marked in a location for the purpose of inspection that is readily visible when inspected before backfilling. The marking inscription shall include the following: a. Name of manufacturer; b. Model or serial number, if available; c. Effective volume and unit of measure; d. Maximum depth of earth cover and external loads the tanks is designed to resist; and e. Inlet and outlet identifications, if relevant. B. Septic Tanks 1. The manufacturer shall provide sufficient information to demonstrate that the tank will meet the design specification. 44 1111 FOraliKAL :'i flY.:11.V,N> 1?li 114 :41:C95.1iiiii1), 1111! Reception#: 848421 04/2212014 09:31:33 PM Jean Rlberice 49 of 80 Rec Fee $0 00 Doc Fee 0.00 GARFIELL) COUNTY C:0 43.9 Design Criteria - Components 2. Sizing Requirements: a. Sizing for residential capacity for new installations shall be based upon the number of bedrooms according to Table 9-1: nk Size Based on Number of Bedrooms Number of Bedrooms Tank Capacity (gallons) 2 or 3 1,000 4 1,250 Each Additional 250 b. For multi -family and non-residential applications, a septic tank shall be sized to permit detention of incoming wastewater design flows for a minimum of 48 hours. c. For systems that remove toilet waste for separate treatment, tank capacity may be less than 1,000 gallons, if it provides a minimum of 48 hours detention time. d. Minimum tank size for new installations other than for a single-family residence is 400 gallons. 3. Testing of Septic Tank Watertightness a. Testing of septic tanks must be performed and evaluated as specified in section 9 of ASTM C1227-12 (Standard Specification for Precast Septic Tanks) for concrete tanks or in Standard IAPMO/ANSI Z1000-2007 (American Standards for Prefabricated Septic Tanks) for other prefabricated septic tanks. b. Each unit shall be inspected in the field for conditions that may compromise its watertightness. c. The inspection in the field shall be conducted by the local public health agency and be performed after the tank installation but before backfilling. d. If the inspection in the field indicates that the tank may be damaged or is not watertight, the inspector may require that the tank be tested for watertightness by the tank manufacturer or the system contractor. 4. Septic Tank Design and Dimension Criteria a. A septic tank shall have two or more compartments or more than one tank may be used in series. The first compartment of a two-compartment tank or the first tank in a series shall hold no less than one-half of the required effective volume. b. Inlet invert shall be at least two inches higher than the outlet invert. c. inlet tee or baffle shall extend above the surface of the liquid at least five inches and shall extend a minimum of eight inches below the liquid surface. d. Outlet tee or baffle shall extend at least 14 inches below the outlet invert and, if needed, be modified to accommodate an effluent screen. The outlet tee or baffle that accommodates an effluent screen must be located so that the effluent 45 1111 K40111,44 :I 111I II 1 Reception#: 848421 O4i2212014 09.31 33 AM Jean Alberico 50 of 9Q Rec Fee $0 00 Doc Fee 0 OQ GARFIELD COUNTY CO 43.9 Design Criteria - Components screen has sufficient clearance to be removed through the access opening with a riser in place. e. The distance from the outlet invert to the underside of the tank top shall be at least ten inches. f. Liquid depth shall be a minimum of 30 inches and the maximum depth shall not exceed the tank length. g. The transfer of liquid from the first compartment to the second or successive compartment shall be made at a liquid depth of between 35 and 40 percent of the liquid depth measured from the liquid surface. h. At least one access manhole no less than 20 inches across shall be provided in each compartment of a septic tank. A septic tank shall have a minimum of 25 square feet of liquid surface area and have at least a six-foot separation between inlets and outlets. Septic tanks in series, combined, shall have a minimum of 25 square feet of liquid surface area and the sum of the distances between inlets and outlets of all tanks must be at least six feet. The requirements for liquid surface area and separation between inlet and outlet may be waived for tanks with less than 750 gallon effective volume. 5. Concrete Septic Tank Structural Design a. Concrete septic tanks shall comply with the structural design criteria of ASTM C1227-12 (Standard Specification for Precast Septic Tanks). b. The design for each tank model and size by each manufacturer must be certified by a professional engineer as complying with these design and structural requirements and the watertightness standard of this regulation. c. Certification by a professional engineer must be submitted to the Division for acceptance. d. Tank slab lids or mid -seam tanks shall be sealed to be watertight. e. Connections between tank and risers shall be sealed to be watertight. 6. Fiberglass, Fiberglass -Reinforced Polyester, and Plastic Tanks a. All fiberglass, fiberglass -reinforced polyester, and plastic tanks shall meet the minimum design and structural criteria of IAPMO/ANSI Z1000-2007 (American Standards for Prefabricated Septic Tanks) and be certified by a professional engineer as meeting these standards. The professional engineer certifying the criteria must be registered or licensed in the United States, but need not be registered in Colorado. b. All tanks shall be sold and delivered by the manufacturer or manufacturer's designated representative, preferably completely assembled. On-site tank assembly will be allowed on an as -needed basis. c. Tanks shall be structurally sound and support external forces as specified in the standard referenced above when empty and internal forces when full. Tanks 46 11111 fIr1L1nirlidi' ., 1I K1M10,1V.IIIIQ'At'1' /III I ReceptionI: 848421 04122,2014 09 31 33 AM Jean Alberico 51 of 80 Rec. Fee 50 00 Doc Fee 0 00 GARFIELD COUNTY CO 43.9 Design Criteria - Components shall not deform or creep resulting in deflection of more than five percent in shape as a result of loads imposed. d. All tanks shall be constructed of sound, durable materials and not be subject to excessive corrosion, decay, frost damage, or cracking. e. All seams or connections including to risers shall be sealed to be watertight. 7. Metal tanks are prohibited. C. Abandonment of Tank 1. A tank may be completely removed and the parts disposed of safely. 2. If the tank will remain in place: a. The tank shall be pumped to remove as much waste as possible; b. The bottom of the tank shall be broken so the tank neither floats nor fills with water; c. The top must be collapsed and the sides may be broken into the void; d. The remaining void shall be filled with gravel, sand or compacted soil; and e. The filled excavation will be graded to surroundings, allowing for settling. 3. The local public health agency may require abandonment of a tank that is deemed to be a hazard. D. Pipe Standards and Bedding Requirements: 1. Pipe Standards a. All wastewater lines used in an OWTS shall be constructed of compatible pipe, primer, bonding agent, and fittings. b. Where unperforated plastic pipe and fittings are used for gravity flow, the minimum wall thickness of the pipe shall conform to ASTM Standard D 3034 or equivalent or greater strength. Schedule 40 pipe is preferred. c. Perforated distribution pipe surrounded by rock within a soil treatment area shall have a minimum wall thickness and perforations conforming to ASTM Standard D 2729 or equivalent or greater strength. Corrugated polyethylene pipe with smooth interior that meets ASTM F405 or AASHTO M252 specifications or equivalent may be used. d. Schedule 40 or pipe of equivalent or greater strength shall be used for the placement of piping under driveways or roadways and in instances where sewer line setback distances are granted a variance for any reason. e. Tile pipe, open joint pipe, and cast iron pipe must not be used in an OWTS. f. Pressure pipe must be rated for the intended use to accommodate pump discharge pressure. 47 ■III I tir1rilligi A `r Iiiu'L14111011111, l 11111 Reception#: 848421 04122!2014 09 31.33 AM Jean Rlberico 2 of 80 Rec Fee,$0.00 Doc Fee 0,00 GARFIELD COUNTY CO 43.9 Design Criteria - Components 2. Bedding: All system piping, except for distribution laterals within the soil treatment area, shall be bedded with select material before final inspection by the local public health agency. Select bedding material shall consist of loose, granular material, free from stones, clods, frozen soil, or other deleterious material. Select material may consist of on- site job -excavated or imported material. Bedding material must be mechanically compacted to support piping. E. Distribution Box: A distribution box, if used, shall be of sufficient size to distribute effluent equally to the lateral lines of a trench or absorption bed system. The box shall be constructed with the inlet invert at least one inch above the level of the outlet inverts. Flow equalizers or similar devices shall be used to adjust the flow between lines. Access to the box shall be provided with a manhole riser with access lid at or above grade if the top of the box does not reach final grade. F. Drop Box: In sequential or serial distribution, a watertight box may be used to transfer the effluent to the following trench when the effluent in a trench has received the designed level for overflow to the next trench. A drop box shall have a riser at or above final grade, if the top of the drop box does not reach final grade. Outlet lines in sequential distribution shall be designed and installed so that they may be capped off for resting periods. G. Step-down/Relief Line: In sequential or serial distribution, an unperforated pipe may be used to transfer the effluent to the following trench when the effluent in a trench has received the designed level for overflow from that trench. H. Wastewater Pumping and Dosing Siphon Systems 1. Pumps a. Non -clog pump opening shall have at least two-inch diameter solids handling capacity where raw wastewater is pumped. A pump opening shall not have more than 3/4 -inch diameter solids handling capacity if previously settled effluent is pumped. b. Pumps must be certified to the applicable UL or CSA electrical safety standard, bear the seal of approval of CSA, UL or an equivalent testing program and be constructed of corrosion resistant materials. c. Grinder pumps must also be certified to NSF/ANSI Standard 46 and bear the seal of approval of the NSF or equivalent testing and certification program. 2. Floats and Switches a. Automatic liquid level controls must be provided to start and shut off pumps at a frequency or level specified in the design. b. Floats must be mounted on a stem separate from the pump discharge piping to allow for removal, adjustment, and replacement of the float without removing the pump. c. Float switches must be certified to the applicable UL or CSA electrical safety standard, bear the seal of approval of CSA, UL or an equivalent certification program and be constructed of corrosion resistant materials. 48 WI:H.044i II III Reception#: 848421 04/22/2014 09.31 33 AM Jean Alberico 53 of BO Rec Fee$0 00 Doc Fee.O 00 GARFIELD COUNTY GO 3. Location of Pump or Siphon 43.9 Design Criteria - Components a. A pump may be, or a siphon shall be, installed in a separate tank following the septic tank and be of sufficient volume to allow pump or siphon cycling commensurate with the design capacity. The use of a three -compartment septic tank, sized to provide effective volume in the first two compartments with the pump in the third compartment, is acceptable. b. The second compartment of the septic tank shall not be used as the pump tank unless it can be demonstrated to the satisfaction of the local public health agency that the minimum 48-hour detention time will not be decreased and the pump is screened or provided with an approved filtering device to assure that only liquid effluent will be discharged. 4. Pump or Siphon Discharge Piping a. The discharge line from the pumping or siphon chamber shall be protected from freezing by burying the pipe below frost level or sloping the pipe to allow it to be self -draining. Drainage shall be provided through the bottom of the pump or through a weep hole located in the discharge line prior to exiting the tank. b. The pump discharge piping shall have a quick disconnect that is accessible within the riser to allow for easy pump access and removal. c. The pipe shall be sized to maintain a velocity of two or more feet per second. d. Automatic air/vacuum release valves shall be installed at high points in the pressure line where necessary to prevent air or vacuum locking and allow self draining of the lines. 5. Access a. The pump or dosing system tank, chamber, or compartment shall have a minimum 24 -inch diameter access riser, made of corrosion -resistant material, extending to or above ground level. b. The access riser must have a watertight connection to the pump or dosing chamber/compartment to prevent infiltration or exfiltration. 6. Splice Box a. Splice boxes shall be located outside the pump system access riser and be accessible from the ground surface. b. No wire splices shall be made inside the tank, dosing chamber or riser. Wire splicing shall be completed with corrosion -resistant, watertight connectors. 7 Controls a. The pump system shall have an audible and visual alarm notification in the event an excessively high water condition occurs. b. The pump shall be connected to a control breaker separate from the high water alarm breaker and from any other control system circuits. 49 ■III IV{icir+ Killit .i li,hfN1741 ILLici If: 'LkiiIi,iii 11111 Reception4: 848421 04x2272010. 09 31 33 ASI Jean Aiberico 54 of 80 Rec Fee $0 00 Doc Fee 0 00 GARFIELO COUNTY CO 43.10 Design Criteria— Soil Treatment Area c. The pump system shall have a switch so the pump can be manually operated. d. The pump system for pressure dosing and higher level treatment systems shall have a mechanism for tracking either the amount of time the pump runs or the number of cycles the pump operates. e. Control panels shall be UL listed. Effluent Screens 1. Effluent screens shall be installed in all septic tanks in new installations and repairs where the septic tank is replaced. 2. If a pump or dosing siphon is used to remove septic tank effluent from the final compartment of the septic tank, an effluent screen must be provided prior to the pump or siphon inlet. A pump vault equipped with a filter cartridge may be considered equivalent to an effluent screen preceding the pump. 3. The effluent screen shall be cleaned at manufacturer -recommended intervals, or more often, if use patterns indicate. 4. An alarm may be installed on an effluent screen indicating need for maintenance. J. Grease Interceptor Tanks 1. All commercial food service facilities and other facilities generating fats, oils and greases in their waste must install a grease interceptor tank. 2. Grease interceptor tanks shall treat only those portions of the total wastewater flow in which grease and oils are generated. 43.10 Desiqn Criteria— Soil Treatment Area A. The size and design of the soil treatment area shall be based on the results of the site and soil evaluation, design criteria, and construction standards for the proposed site and OWTS selected. B. At proposed soil treatment area locations where any of the following conditions are present, the system shall be designed by a professional engineer and approved by the local public health agency: 1. The soil classifications are Types 0, 3A, 4, 4A, and 5 and Treatment Levels TL2, TL2N, TL3, and TL3N as specified in Table 10-1 of this regulation; 2. The maximum seasonal level of the ground water surface is less than four feet below the bottom of the proposed absorption system; 3. A restrictive layer exists less than four feet below the bottom of the proposed absorption system; 4. The ground slope is in excess of thirty percent; or 5. Pressure distribution is used. 50 1111 f iviri�1 Vilil!FiGYlili ii' ll'riaLeeli:1 111 UIR;1;1 114,1I II! Reception#: 848421 04/22/2014 09 31.33 AM Jean Alberico 55 of 80 Rec Fee•$0.00 Dec Fee 0 00 GARFIELD COUNTY CO 43.10 Design Criteria— Soil Treatment Area C. Calculation of Infiltrative Surface of Soil Treatment Area 1. The infiltrative surface of a trench or bed receiving any treatment level of effluent is only the bottom area. No sidewall credit is allowed except in deep gravel trenches and seepage pits that are permissible in repairs. 2. Long-term acceptance rates (LTARs) are shown in Table 10-1. 3. Factors for adjusting the size of the soil treatment area are in Tables 10-2 and 10-3. 4. The required area for a soil treatment area is determined by the following formula: Soil Treatment Area in square feet required = Design Flow (in gallons per day) LTAR (in gallons per day per square foot) a. Adjusted Soil Treatment Area = Required Soil Treatment Area x Size Adjustment Factor(s). b. Size adjustment factors for methods of application are in Table 10-2. c. Size adjustment factors for types of storage/distribution media are in Table 10-3. d. A required soil treatment area receiving TL1 effluent may be multiplied by one size adjustment factor from Table 10-2, Table 10-3, or both. e. A soil treatment area receiving TL2, TL2N, TL3, or TL3N effluent must be pressure dosed. The distribution media in Table 10-3 may be used for distribution of higher level treatment system effluent, but an additional reduction factor from Table 10-3 shall not be used. 51 Design Criteria— Soil Treatment Area 1111 lidW K 11'i a, KJ!:1'ilM DINVIIOilk,:i1.11,11, 11111 Recept i ontt : 848421 04122!2014 0931.33 Aft Jean Alberico 56 of 60 Pec Fee $0 00 Doc Fee 0 00 GARFIELD COUNTY GO Long-term Acceptance Rate (LTAR); Gallons per day per square foot Treatment Treatment Treatment Treatment Level 2' Level 2N' Level 3' Level 3N1* Minimum 2 -foot deep unlined sand filter required2 •t O co G 0.80 O 6 0.30 a N 0 O 1.40 1 O COD O m co aa) O 0 O N 0 1 0.15 Lo N r 0 O r- O EL) O 0 M O IV C v- O N r- 8 O O O � O Q 0 I 0.30 0 0 - O Treatment Level 1' Minimum 3 -foot deep unlined sand filter req u ired2 co p w 0 10 O 0.35 1) 0 0.20 r O O T. O Soil Type, Texture, Structure and Percolation Rate Range Percolation Rate (MPI) V V Lo N 0 V CO 41-60 so 17 m 0 CA ti en CV w 4. N ° 7 0 7 0 - 0 0 O 2 (Moderate) 3 (Strong) 1 (Weak) Massive N ,r es 2 2, ^ r USDA Soil Structure - Shape f 1 lO Y d y CO O a °° _! > co c? (auou) 0 'N9 'lid PR, BK, GR SC 0 O PR, BIC, GFt Y m el O i' USDA Soil Texture Soil Type 1 with more than 35% Rock (>2mm); Soil Types 2-5 with more than 50% Rock (>2mm) Sand, Loamy Sand 1 Sandy Loam, Loam, Silt Loam Sandy Loam, Loam, Silt Loam Sandy Clay Loam, Clay Loam, Silty Clay Loam Sandy Clay Loam, Clay Loam, Silty Clay Loam Sandy Clay, Clay, Silty Clay Sandy Clay, Clay, Silty Clay Soil Types 2-4A II)~ O T N N I.')g '0 Shaded areas require system design by a professional enginee Treatment levels are defined in Table 6-3. Unlined sand filters in these soil types shall provide pathogen removal. Design shall conform to section 11.C.2.c, Unlined Sand Filters .111 11 III Reception#: 848421 04/22/2014 09:31:33 RM Jean Rlberico 57 of BO Rec Fee $0.00 Doc Fee 0 00 GARFIELD COUNTY CO 43.10 Design Criteria— Soil Treatment Area D. Allowable Soil Treatment Area Reductions and Increases: 1. The soil treatment area size determined by dividing the design flow rate by the long-term acceptance rate may be adjusted by factors for method of treatment, soil treatment area design, and type of distribution media. 2. For the purpose of the table, a "baseline system," i.e. adjustment factor of 1.00, is considered to be Treatment Level 1 (TL1) applied by gravity to a gravel -filled trench. 3. The maximum reduction from all combined reductions including higher level treatment shall be no greater than 50 percent of the baseline system required for a soil treatment area. 4. Reductions for use of the higher level treatment categories listed in Table 10-1 shall only apply provided the system is inspected and maintained as specified in the requirements of section 14.D., Permitting and Oversight of Maintenance for Soil Treatment Area Reductions and Vertical and Horizontal Separation Distance Reductions Based on Use of Higher Level Treatment. Table 10-2 Size Adjustment Factors for Methods of Application in Soil Treatment Areas tins Treatment Levels 1, 2, 2N, 3 and 3N Effluent Type of Soil Treatment Area Method of Effluent Application from Treatment Unit Preceding Soil Treatment Area . Gravity Dosed (Siphon or Pump) Pressure Dosed Trench 1.0 0.9 0.8 Bed 1.2 1.1 1.0 Table 10-3 Size Adjustment Factors for Types of Distribution Media in Soil Treatment Areas ment Level 1 Effluent Type of Soil Treatment Area Type of Storage/Distribution Media Used in Soil Treatment Area Rock or Tire Chips Manufactured Media Other Than Chambers Chambers Trench or Bed 1.0 0.9 0.7 E. Design of Distribution Systems 1. General a. The infiltrative surface and distribution lines must be level. 53 VIII 14iIiirrig1 ,1111,', 111 Reception#: 848421 04/22/2014 09:31.33 nM Jean Alberico 5R of 80 Rec Fee $0 00 Doc Fee:0 00 GARFIE.LD COUNTY CO 43.10 Design Criteria— Soil Treatment Area b. The infiltrative surface must be no deeper than four feet unless adequate treatment at a deeper level can be demonstrated and is approved by the local public health agency. The depth will be measured on the downslope side of the trench or bed. c. Trenches must follow the ground surface contours so variations in infiltrative surface depth are minimized. Beds must be oriented along contours to the degree possible. d. Pipe for gravity distribution must be no less than three inches in diameter. e. A final cover of soil suitable for vegetation at least ten inches deep must be placed from the top of the geotextile or similar pervious material in a rock and pipe system, chamber, or manufactured media up to the final surface grade of the soil treatment area. f. Following construction, the ground surface must be graded to divert stormwater runoff or other outside water from the soil treatment area. The area must be protected against erosion. Subsurface drains upslope of the soil treatment area may be installed to divert subsurface flow around the area. g. Backfilling and compaction of soil treatment areas shall be accomplished in a manner that does not impair the intended function and performance of the storage/distribution media and soil and distribution laterals, allows for the establishment of vegetative cover, minimizes settlement and maintains proper drainage. 2. Distribution Lines a. Distribution between lines in a soil treatment area must be as even as possible. Uneven settling of portions of the distribution system following construction must be addressed by provisions in the design to adjust flows between lines. b. Distribution lines longer than 100 feet may be pressure dosed or the application of the effluent shall be at the center of the line. These systems must be designed by an engineer. c. The end of a distribution pipe must be capped, unless it is in a bed or trenches in a level soil treatment area, where the ends of the lines may be looped. d. Inspection Ports (1) An inspection port accessible from ground surface must be installed at the terminal end of each line. The bottom of the inspection port tube must extend to the infiltrative surface and not be connected to the end of the distribution pipe. Inspection ports in chambers may be installed according to manufacturer's instructions if the infiltrative surface is visible or can be measured from the inspection port. (2) Additional inspection ports connected to distribution pipes may be installed. (3) An inspection port shall be installed at the initial end of each line. 54 ■III irn l'ilT41t11.111 #,IPN1'11111 Reception#: 848421 04/22/2014 09.31-33 AM Jean Alberico 59 of 80 Rec Fee 1,0 00 Doc Fee:0 00 GARFIELD COUNTY CO 43.10 Design Criteria— Soil Treatment Area (4) The top of inspection ports may be below the final grade of the surface if each has a cover at the surface such as a valve box for a lawn irrigation system. e. Trenches (1) Trenches must be three feet wide or less. (2) The separating distance between trenches must be a minimum of six feet sidewall-to-sidewall. (3) Perforated distribution pipe used in a trench must be as close to the center of the trench as possible. (4) Perforations must be oriented downward unless pressure distribution is used and provision for pipe drainage is included. f. Beds (1) Maximum width for a bed must be 12 feet, unless the bed receives effluent meeting Treatment Level 2 quality or better. (2) The separating distance between beds must be a minimum of six feet sidewall-to-sidewall. (3) The separating distance between parallel distribution lines in an absorption bed must not exceed six feet and a distribution line must be located within three feet of each sidewall and endwall of the absorption bed. g. Serial and Sequential Distribution: (1) A serial or sequential distribution system may be used where the ground slope does not allow for suitable installation of a single level soil treatment area unless a distribution box or dosing chamber is used. (2) The horizontal distance from the side of the absorption system to the surface of the ground on a slope must be adequate to prevent lateral flow and surfacing. (3) Adjacent trenches or beds must be connected with a stepdown/relief line or a drop box arrangement such that each trench fills with effluent to the top of the gravel or chamber outlet before flowing to succeeding treatment areas. 3. Storage/Distribution Media a. Rock and Pipe (1) The pipe must be surrounded by clean, graded gravel, rock, or other material of equal efficiency which may range in size from 1/2 inch to 2 1/2 inches. At least six inches of gravel, rock or other material must be placed below the pipe. The gravel, rock or other material must fill the trench around the pipe and at least two inches above the top of the distribution pipe. 55 11111 e1rlil'ilf,4111 'eiEr 10,1:i' Iill'riIr:h'N10.11,441'' 111111 Reception 848421 04/22/2014 09 31:33 AM Jean Rlberico 60 of 80 Ree Fee•$0.00 Doc Fee -0.00 GPRFIELD COUNTY C0 43.10 Design Criteria— Soil Treatment Area (2) The top of the placed gravel or such material used must be covered with non -woven permeable geotextile meeting a maximum thickness rating of 2.0 ounces per square yard or equivalent pervious material. An impervious covering must not be used. b. Tire Chips (1) The pipe may be surrounded with clean, uniformly -sized tire chips. (2) Tire chips must be nominally two inches in size and may range from 1/2 inch to a maximum of four inches in any one direction. (3) Wire strands must not protrude from the tire chips more than 0.75 inches. (4) Tire chips must be free from balls of wire and fine particles less than two mm across. (5) The top of the tire chips used must be covered with non -woven permeable geotextile meeting a maximum thickness rating of 2.0 ounces per square yard or equivalent pervious material. An impervious covering must not be used. c. Chambers (1) Chambers must be installed with the base on the infiltrative surface. (2) Installation must be according to manufacturer's instructions. (3) Effluent may be distributed by gravity or pressure dosing. d. Manufactured Media (1) Manufactured media must be installed with the base on the infiltrative surface. (2) Installation must be according to manufacturer's instructions. (3) Effluent may be applied by pressure distribution only if the manufacturer specifies suitability of the product for that use. e. Pressure Distribution (1) Design of pressure distribution systems must include: (i) Dose size and frequency for flows and soil or media long-term acceptance rate; (ii) Pipe diameter and strength requirements; (iii) Orifice size and spacing; and (iv) Distal pressure head. (2) Cleanouts must be installed at the end of each line. 56 1111lariAK41111.MMi1:fleaI'iiikil>'riiimity1,11 II Reception#: 848421 04/22/2014 09 31 33 AM Jean Alberico 61 of 80 Rec Fee $0 00 Doc Fee 0 00 GARFIELD COUNTY CO f. Driplines 43.10 Design Criteria— Soil Treatment Area (1) The infiltrative surface area must be calculated using the long-term acceptance rate for the site or a more conservative value if recommended by the manufacturer. (2) Driplines must be installed on manufacturer's spacing recommendations. (3) Drainback must be provided for all drip lines, pipes and pumps. (4) Provisions must be made to minimize freezing in the distribution lines, driplines, relief valves, and control systems. (5) Provisions must be made for backflushing or other cleaning. F. Alternating and Sequencing Zone Systems 1. Alternating Systems a. An alternating system must have two zones that must be alternated on an annual or more frequent basis. b. Each section must be a minimum of 50 percent of the total soil treatment area. Size adjustment factors for methods of effluent application or type of distribution media shall not be allowed. c. A diversion valve or other approved diversion mechanism may be installed on the septic tank effluent line allowing soil treatment area sections to be alternated. d. The diversion mechanism must be readily accessible from the finished grade. 2. Sequencing Zone Systems a. Sequencing zone systems have more than two soil treatment area sections that are dosed on a frequent rotating basis. b. Where soil conditions are similar between the sections, each section area shall be the same size. If soil conditions are such that long-term acceptance rates are different, each section may be sized for the same dose, but different long-term acceptance rates. c. An automatic distribution valve must be used. d. Dosing of each system must be evaluated by the design engineer based on projected daily flow rates, number of zones, and soil types. G. Dosing: Dosing may be used for soil treatment area distribution. The dose must be sized to account for the daily flow and the dosing frequency. H. Soil replacement must be permitted to bring the soil within the requirements of suitable soil. Added soil must meet the specifications of sand filter media, as specified in section 43.11.C.2.a.(1). All added soil must be completely settled prior to installation of components as specified and approved by the design engineer. The loading rate for sand filters must be used. Pressure distribution must be used. 57 ■III I11111r4k141iiI+hr17�,71r4hn01.,Eiii,1I Ill Reception#: 848421 04(22'2014 09 31:33 AM Jean Rlberico 62 of 90 Rec Fee $0.00 Doc Fee:0.00 GPRFIELD COUNTY CO 43.10 Design Criteria— Soil Treatment Area Repairs 1. When space is not available or if there are other site limitations that preclude other soil treatment area options for OWTS repairs, wide beds, deep gravel trenches, and seepage pits may be considered for repairs only. Other options are vaults or higher level treatment systems, if the local board of health permits them. 2. Wide Beds: For repairs, beds may be wider than 12 feet without being required to receive effluent meeting Treatment Level 2 quality or better. 3. Deep Gravel Trenches a. The length of an absorption trench or bed may be calculated by allowance for the sidewall area of additional depth of gravel in excess of six inches below the bottom of the distribution pipe according to the following formula: Adjusted Length = L x (W+2) (W+1+2D) Where: L = length of trench prior to adjustment for deep gravel W = width of trench or bed in feet D = additional depth in feet of gravel in excess of the minimum required six inches of gravel below the distribution pipe b. Maximum allowable additional depth is five feet. c. Percolation tests and soil profile hole or soil profile excavation test pit evaluations must be performed at the proposed infiltrative surface depth. d. The reduction in field size area with the use of chambers must not be applied to deep gravel systems. 4. Seepage Pits a. For repairs, potential for risk to public health and water quality may be evaluated by the local public health agency. If risk is low in the determination of the local public health agency, a seepage pit without higher level treatment may be used. b. If the risks are not low, higher level treatment of at least TL2 must be attained prior to discharge to these systems for final disposal. c. A seepage pit shall consist of a buried vertical cylinder with holes in the wall. (1) Pits must be provided with both vertical sidewall and top supporting structural concrete or other material of equal structural integrity. (2) The excavation must be larger than the cylinder by at least 12 inches on each side. (3) The over -excavated volume must be filled with rock ranging in size from 1/2 inch to 2 1/2 inches. 58 `r�41Islitg ri�� IV��� �I 11 Reception#: 848421 04/22/2014 09 31:33 8N1 Jean Rlberico 53 of 80 Rec Fee $0 00 Doc Fee 0.00 GARFIELD COUNTY CO43.11 Design Criteria — Higher Level Treatment Systems (4) The capacity of the pit must be computed on the basis of long-term acceptance rates determined for each stratum penetrated. The weighted average of the results must be used to obtain a design figure. (5) Soil strata in which the percolation is slower than 30 minutes per inch must not be used for absorption or seepage. These strata must not be included in the weighted average to determine the long-term acceptance rate. (6) The infiltrative surface of the pit is the vertical wall area (based on dug perimeter) of the pervious strata below the inlet plus the bottom area inside the vertical cylinder. d. Pits must be separated by a distance equal to three times the greatest lateral dimension of the largest pit. For pits over 20 feet in depth, the minimum space between pits must be 20 feet. e. The construction of new seepage pits for the treatment and dispersal of on-site wastewater on new sites is prohibited unless: (1) The seepage pit is designed by a professional engineer; and (2) The design includes higher level treatment of at least TL2. 5. Vaults a. The allowable use of vaults for repairs in a local jurisdiction is determined by the local board of health. b. Criteria for vaults are in section 12.D. of this regulation. 6. Higher Level Treatment Options a. Reduction in required soil treatment area for repairs is possible with higher level treatment. b. Design criteria for higher level treatment systems are in section 11. 43.11 Design Criteria — Higher Level Treatment Systems A. General 1. Higher level treatment systems must be designed by a professional engineer. 2. Higher level treatment systems may be public domain technology systems or proprietary systems. a. Public domain technology systems must be designed, installed and maintained according to established criteria and additional criteria established by the local public health agency. When design criteria are not specifically provided in this regulation, the criteria used in the design must be from a reference commonly used as an industry standard and the criteria must be cited in the design. 59 Custom Soil Resource Report Three values are provided to identify the expected Low (L), Representative Value (R), and High (H). Physical Soil Properties -Rifle Area, Colorado, Parts of Garfield and Mesa Counties Map symbol and soil name Depth Sand Silt Clay Moist bulk density Saturated hydraulic conductivity Available water capacity Linear extensibility Organic matter Erosion factors Wind erodibility group Wind erodibility index Kw Kf T In Pct Pct Pct g/cc micro m/sec In/In Pct Pct 55 -Potts loam, 3 to 6 percent slopes Potts 0-4 -44- -41- 10-15- 20 1.25-1.33- 1.40 4.23-23.28-42.3 4 0.14-0.16-0.1 7 0.0- 1.5- 2.9 1.0- 1.5- 2.0 .37 .37 5 5 56 4-28 -33- -36- 27-31- 34 1.25-1.33- 1.40 1.41-2.82-4.23 0.17-0.19-0.2 0 3.0- 4.5- 5.9 0.5- 0.8- 1.0 .32 .32 28-60 -42- -38- 15-20- 25 1.25-1.33- 1.40 4.23-23.28-42.3 4 0.14-0.16-0.1 7 0.0- 1.5- 2.9 0.0- 0.3- 0.5 .37 .37 19 r_ { �h. Graphic Scale 0 10 20 40 In Feet: 11' = 20' NOTE IT IS RECOMMENDED THAT POLYLOK (OR EQUAL) FLOW DISTRIBUTION WE/RS BE INSTALLED ON THE OUTLET OF EACH PIPE TO THE INFILTRATOR TRENCHES. IT IS CR/TICAL THAT FLOW /S EQUALLY DISTRIBUTED TO EACH TRENCH (SEE PRODUCT DETAIL AT RIGHT) i 1 • a 0,111111116 CALL 811 PRIOR TO DIGGING FOR ALL UTILITY CONFLICTS (REPORTED PHONE AND ELECTRIC CONFLICTS MAY EXIST WITH SEWER LINE CONSTRUCTION) 11. 6 t 1114 z•rmitx.44 ita INSPECTION PORT - TYP. 4" DIAMETER SOLID WALL ASTM 3034 PVC PIPE DIST. BOX TO S.T.A. (MIN. SLOPE = 2X) PROVIDE DISTRIBUTION BOX WITH POLYLOK WIERS FOR EQUAL FLOW DISTRIBUTION TO CHAMBERED TRENCHES 4" DIAMETER SOLID WALL ASTM 3034 PVC PIPE DIST. BOX TO S.T.A. (MIN. SLOPE = 2%) NOTE: INFILTRATOR TRENCHES MAY FOLLOW SLOPE OF YARD MUST BE INDIVIDUALLY INSTALLED LEVEL F APPROXIMATE LOCATION OF EXISTING SOIL TREATMENT AREA APPROXIMATE LOCATI " OF EXISTING 1,000 Gol�Tv IN CONCRETE SEPTIC ITA I M ' iiii ado, r r 1 a — t ROUTE 4" PVC ASTM' 3034 SOLID WALL PVC PIPE BACK TO SECOND CHAMBER OF SEPTIC TANK, PROVIDE CLEAN OUTS AT BENDS IN _ PIPE, SLOPE PIPE AT 1/4" PER FOOT 80.00' . • SOIL TREATMENT AREA SET BACK LINE alibt I III I , I I 1 I I i I I I411111 I I I I I , I I I I 1 I I , I I I I 20 INFILTRATOR QUICK4 UNITS PER TRENCH O O O SOIL TREATMENT AREA SET BACK LINE 1 1 1 I 1 I I 1 1 I I I I 1 1 I I Of/I 0 of INSPECT/ON PORT - TYP. PROPERTY LINE QUICK4 STANDARD MULTIPORT END CAP Schematic for Permit and Construction 4" PVC FROM HOUSE 4 %FOOT MIN. SLOPE sG m ASSURE EXISTING RISER FOR PUMP ACCESS Tough engineered plastic. Will not corrode. Installs without tools. Adjustment knob moves opening up or down in 1/16" /increments. fatal movement is 71H". f 1 Simple to Install, just push into any 4" pipe. SCH. 40, SDR 35, and thin wall. Water tight fit POL YL OK PRODUCT DETAIL MOUND FOR PROPER DRAINAGE ASSURE EX/STING RISER FOR PUMP ACCESS • a.4 a o PROVIDE TRAFFIC RATED LID IF IT IS ANTICIPATED THAT VEHICLES WILL TRAVEL OVER SEPTIC TANK // NATIVE BACKFILL 34" 36" Mob— QUICK4 CHAMBER TYPICAL INSTALLATION DETAIL (Not to Scale) 1000 GAL. SEPTIC TANK NOT TO SCALE 4" SOL/D WALL 3034 PVC PIPE AT 1/4 /FOOT SLOPE (MIN.) TO DISTRIBUTION BOX PROVIDE AN EFFLUENT FILTER ON DISCHARGE SIDE OF SEPT/C TANK IF NONE CURRENTLY EX/STS INFILTRATOR SYSTEMS INC. QUICK4 STANDARD CHAMBER INSPECTION PORT ESTABL/SH VEGETATIVE COVER / \/ 8' MAX BUR/AL DEPTH 12" MIN., H-70 LOAD AREAS 6" MIN., NON—TRAFFIC AREAS 72" a PIPE CAP, TYP 4" OBSERVATION PIPE, TYP NATIVE BACKFILL, TYP EXCA VA TION /NFIL TRA TOR QUICK4 GRAVELLESS CHAMBER EXISTING GRADE n 6' MIN (10' SHOWN) 6" DIA. PVC PIPE SLEEVE Z � N00 (TYP) QUICK4 TRENCH DETAIL NOT TO SCALE NOTE: IF OVER 48" IN DEPTH, PROVIDE AN AIR VENT TO EACH TRENCH IN LIEU OF OBSERVATION PORT AIR VENT TO EXTEND 36" ABOVE ADJACENT FINISH GRADE 118 West Sixth Street, Suite 1C Glenwood Springs, CO 01601 970.945.1004 www.sgm-inc.com 1 18 West 200 Glenwood Springs, CO 81601 www.sgm-inc.com Garfield County, Colorado Harbin Residence NW It of S 5, T6S, R92W, Rifle, CO Revision Date By 1 OWTS Design and Details GRAVITY SYSTEM ALTERNATIVE Job No. 2019-114.001 Drawn by: JSS Date: 01/21/19 QC: PE: JSS File: Harbin -BM Of 1 1 J