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HomeMy WebLinkAboutOWTS Design Report 03.03.2020ESGM www.sgm-rnc.com March 3,2020 Mr. Andy Schwaller, Building Official Garfield County Building Department 108 8th Street Glenwood Springs, CO 81601 RE Burkett OWTS Tract 8, Antlers Orchard Development TBD CR 237, Silt, Colorado OWTS Design Dear Andy, The purpose of this letter is to transmit the design regarding the onsite waste water treatment system (OWTS) for Bob and Robin Burkett to be located on Tract 8, Antlers Orchard Development in Silt, Colorado, Assessor parcel number 2L27362OOO71. The property is accessed by a shared driveway north and east of the property off of CR 237 (Harvey Gap Road) between Rainbow Road and CR 250 north of Silt and south of Harvey Gap reservoir. The address is yet to be determined. The specific location of the property in question is located in Figure L. Figure 1- Vicinity Map t: Accounl R084279 owner SURKEIT. BOBBY R & RoBIN G Phylic€l Addrc$ Not ovoiloble null null Molllng Addr.r! PO BOX 184 NEW CASILE, CO 4t647 Acres I O 201? Mlll l€vy 63.9580 GLENWOOD SPRINGS llSWestSixlh St, Suite 200 | Glenwood Springs, CO 8.l601 | 970.945.1004 ESGM www.sgm-rnc.com This onsite wastewater treatment system is intended to serve a new four bedroom house and future ADU in a future barn/shop building. As you will see on the schematic drawings and information attached, the home will be provided with a gravity service from the home to a minimum sized 1,250 septic tank that can be either the standard poly tank (manufacturer provided) or a precast concrete septic tank. From the septic tank, the effluent supernatant will be transported to a proposed distribution box followed by the lnfiltrator Quick4 trench disposal system. Each of the five proposed trenches is to be 96 feet long with 24 Quick4 lnfiltrators to comprise the system. Standard end caps are proposed on the end of each trench along with inspection ports. The piping from the home to the tank, distribution box and infiltrator trenches shall be a minimum diameter of 4" diameter ASTM 3034 PVC. Locations of the new tank, distribution box and infiltrator trenches will be specified in the attached drawing plan of this package in an area located just south and east of the proposed building honoring property line, building, gulch, pond, well and easement setbacks. During soils testing, no groundwater or bedrock levels were found to exist within 8' of the ground surface (ie., 4 ft. of the bottom of the proposed infiltrators). The overburden soils were consistent and appeared to be a sandy clay loam material consistent with soil type 3 identified in Garfield County OWTS Regulations Table L0-L in the upper 96" while a layer of slightly clayey, sandy, gravels exist below that (still consistent with Soil Type 3 and consistent with the CTL Thompson bores). Research was performed to gain insight on the specific soils parameter utilizing the NRCS WebSoil survey. The tactile soil analysis is consistent with the Heldt Clay Loam identified in the NRCS WebSoil Survey. The exhibits attached to this letter identify the information that was researched in addition to the testing performed to help determine the LTAR (Long Term Acceptance Rate) for the STA (Soil Treatment Area) for the design of the new disposal field. Exhibits are listed as follows: 1. Exhibit A: 2. Exhibit B: 3. Exhibit C: NRCS Soils Report CTL Thompson Soils Report OWTS Design and Details Based researched data, the LTAR for the on-site soils is 0.30 gallons per day per square foot. With this data, the STA (Soil Treatment Area) is 2,000 square feet. Because we will incorporate the use of lnfiltrators chambers we have employed the size adjustment factors and reduced the trench size by the following: GLENWOOD SPRINGS I l8 West Sixth St, Suite 200 | Glenwood Springs, CO 8.l60,l | 970.945.1004 ESGM www.sgm-lnc.com For using chambers, a 0.7 factor is applied, thus resulting is an area of 1,400 sf. This results in five infiltrator Quick4 chamber trenches of dimension 96' in length. The attached calculations identify the thought process in the design of this system. The design and layout of the system is shown on the attached drawing following this letter Upon your receipt and review, if you have any questions, please don't hesitate to call Respectfully, SGM-lnc. Jefferey S. Simonson, PE, CFM Principal 261 $2 3t5t2020 GLENWOOD SPRINGS llBWestsixth St, Suite 200 | Glenwood Springs, CO 81601 | 970.945.1004 OWTS Design Report and Calculations Project LocationClient:Bob and Robin Burkett 12901 CR 320 Rifle, Colorado 81650 Date: 3-Mar-20 Flow Data for the OWTS Design 1 Home Use (5 Bedroom Home) Home Use Totals: 500 600 Tract 8 Antler Orchard Development silt, co 0.48 #/day O.48 #ldaV Total= For Home Use, 2 persons per bedroom and 75 gallons per day per person, BOD5 = 0.06 #/person/day for up to 3 bedrooms and 1 person per bedroom there after 600 gpd 600 epd Soil Data for the OWTS Data from on-site soil observations: Appears to be a silty clay loam soil of consistent depth from surface beyond a depth of 8 feet where the depth of the profile pit was excavated. At a depth of 8', neither bedrock or groundwater have been encountered, Data from the web soil survey indicates an Heldt Clay Loam exists. From tactile soil evaluation, CTL Thompson soil report and NRCS Websoil data, the sandy clay load is present 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: 2 600 epd 48 hour detention time for septic tank sizing; lnstall a 1250 gallon tank. Volume= 1200 gpd Sizing of Absorption Field or Soil Treatment Area 5 Going with a soil type 3 and Treatment Level 1, LTAR =o.3 elsf/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 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= For a chamber system in a trench configuration, length= (this would equate to 5 runs of 93.3 feet each) 1400 square feet 467 feet With the effective length of a Quick4 chamber at 4', use 24 chambers per trench for five trenches (total length of each trench is thus 96 feet long) EXHIBIT A NRCS WEBSOIL SURVEY USDA - United States Depaftment of Agriculture NRCS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United Siates Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Gustom Soil Resource Report for Rifle Area, Golorado, Parts of Garfield and Mesa Gounties Burkett Property 0 rti t i, aj: ',,_'',ai(:1., 1-.^ =+t.* ll ",4 -. :! 1'ri1*t I I t I rS r.l q .t n'irft t'; 1ln.*."$r * +si"1[ ir ji ' lbJ. I jt-t. lt E ,!" 4,s*, a i i$t .,-.{{E t , I t F December 15,2019 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/wpsi portal/nrcs/main/soils/healthi) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locatorlapp?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid =nrcs 1 42p2_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. lnformation 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 lndependence 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 Gontents Preface....... How Soil Surveys Are Made. Soil Map..... Soil Map...... Legend........ Map Unit Legend........ Map Unit Descriptions Rifle Area, Colorado, Parts of Garfield and Mesa Counties.... 29-Heldt clay loam, 3 to 6 percent slopes..... 41-Kim loam, 6 to 12 percent slopes....... 56-Potts loam, 6 to 12 percent slopes....... Soil lnformation for All Uses..... Soil Reports Soil Physical Properties. Engineerin g Properties (B u rkett Property)..... References .........2 tr ........8 .........9 ....10 ,...12 ...12 ....14 ....14 ... 15 ... 15 ..17 ..17 ,.17 .17 ..21 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soilsurvey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 Custom Soil Resource Report scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. lf intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. lnterpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit localconditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biologicalactivity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and b Custom Soil Resource Report identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. 7 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. I v 3I *R Custom Soil Resource Report Soil Map 27AN nof* "Y "Y "Y 'T,o *Tl& r t=_-€fio ' r" rii *r{ t 396 34',41"N390 34'41'N I r! t llt-t, I E $ i.: .f t I.rf,rf I'rl I g Rs $ .R N-nl< .*; *iu FS a * C $ Is d t * fr't t *i' ! rl I I E + =-$ t Soi:l Map tmay not be val'id at this scald I'llnu@ 2701w nu l- J n0N 27ccr'0 Map Scale: 1:1,310 if print€d on A potuait (8.5" x 11") sheet. 15 30 60 90 0 50 100 m 300 Map projection: Web lvlercator Comercoordinates: WG$4 Edgetics; UTM Zone 13N WGS84 9 =in RN A 390 3' 32" N 27810 390 3',32',N Custom Soil Resource Report MAP LEGEND MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,0O0. 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 1 2, Sep 13, 2019 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 Area of lnterest (AOl) n Area of lnterest (AOl) Soils E Soil Map Unit Polygons # Soil Map Unit Lines I Soil Map Unit Points Special Point Features Lg Blowout El Borrow Pit X Clay Spot S Closed Depression X Gravel Pit ..." Gravelly Spot O Landfill A Lava Flow C6 Marsh or swamp {'nl Mine or Quarry O Miscellaneous Water (| Perennial Water \,l Rock Outcrop + Saline Spot :.: Sandy Spot € Severely Eroded Spot S Sinkhole h Slide or Slip @ Sodic Spot € Spoil Area 6 Stony Spot A VeryStonySpol t wet Spot l5 Other *' Special Line Features Water Features Streams and Canals Transportation *l Rails * lnterstate Highways Ai. US Routes -- Major Roads , Local Roads Background I Aerial Photography Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misundertanding 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. 10 MAP LEGEND Custom Soil Resource Report MAP INFORMATION imagery displayed on these maps. As a result, some minor of unit boundaries be evident. 't1 Custom Soil Resource Report Map Unit Legend Totals for Area of lnterest Map Unit Descriptions 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. lf 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 impracticalto make enough observations to identify allthe 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 Map Unit Symbol Map Unit Name Acres in AOI Percent ofAOl 29 Heldt clay loam, 3 to 6 percent slopes 2.1 05 3.5 34.50/o 41 se Kim loam, 6 to 12 percent slopes 7.60/o 57.9o/oPotts loam, 6 to 12 percent slopes 6.1 100.0% 12 Custom Soil Resource Report 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. lf intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. 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 so/ serles. 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 so/ 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 assocraflon 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. 13 Custom Soil Resource Report Rifle Area, Colorado, Parts of Garfield and Mesa Counties 29-Heldt clay loam, 3 to 6 percent slopes Map Unit Setting National map unit symbol: inxt Elevation: 5,000 to 6,000 feet F a rm I a n d cl assifi cati on: Fa rmland of statewide i m porta nce Map Unit Composition Heldt and similar soi/s: 90 percent Estimates are based on obseruations, descriptions, and transects of the mapunit. Description of Heldt Setting Landform: Valley sides, alluvial fans Down-slope shape: Convex, linear Across-s/ope shape: Convex, linear Parent material: Fine-textured alluvium derived from sandstone and shale Typical profile H1 - 0 to 8 inches: clay loam H2 - 8 to 21 inches: clay loam H3 - 21 to 60 inches; clay Properties and qualities S/ope;3to6percent Depth to restrictive feature: More than 80 inches Natural drainage c/ass; Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat); Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Gypsum, maximum in profile: 5 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 5.0 Available water storage in profile: High (about 10.2 inches) lnterpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3c Hydrologic Soil Group: C Ecological sife; Clayey Foothills (R048AY289CO) Hydric soilrating: No 14 Custom Soil Resource Report 41-Kim loam, 6 to 12 percent sloPes Map Unit Setting Nationalmap unit symbol: inYS Elevation: 5,000 to 6,000 feet F arml and classification ; Farmland of statewide importance Map Unit Gomposition Kim and similar sol/s: 85 Percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Kim Setting Landform: Benches, alluvial fans Down-slope shape: Convex, linear Across-s/ e shape: Convex, linear Parent material: Alluvium derived from sandstone and shale Typical profile H1 - 0 to 17 inches; loam H2 - 17 to 60 inches.' loam Properties and qualities S/ope; 6lo 12 percent Depth to restrictive feature: More than 80 inches Natural drainage c/ass; Well drained Runoff class.' Low Capacity of the most limiting layer to transmit water (Ksat); Moderately high to high (0.60 to 6.00 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 Available water storage in profile: High (about 9.6 inches) lnterpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: A Ecological slfe; Rolling Loam (R048AY298CO) Hydric soil rating: No 56-Potts loam, 6 to 12 percent slopes Map Unit Setting National map unit symbol: inys 15 Custom Soil Resource Report Elevation: 5,000 to 7,000 feet Farmland classification: Farmland of statewide importance Map Unit Gomposition Potts and similar soils: 85 Percent Esfimafes 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-s/op e shape: Convex, linear Parent material: Alluvium derived from basalt and/or alluvium derived from sandstone and shale Typical profile H1 -0to4inches: loam H2 - 4 to 28 inches: clay loam H3 - 28 to 60 inches: loam Properties and qualities S/ope: 6 to 12 percent Depth to restrictive feature: More than 80 inches Natural drainage c/ass: 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 f/oodrng; 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) lnterpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil GrouP: C Ecological sife; Rolling Loam (R048AY298CO) Hydric soi/ rafing: No 16 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 (Burkett Property) 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 17 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. ln 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. lf the content of particles coarser than sand is 15 percent or more, an appropriate modifier is added, for example, "gravelly." Ctassification 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. ln 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. lf 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 4-7-6. As an additional refinement, the suitability of a soil as subgrade material can be indicated by a group 18 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 pafticles,) passrng 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 rndex (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. 19 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). L-R-H 10-15-2 0 5-8 -10 41-Kim loam, 6 to 12 percent slopes Kim Potts Engineering Properties-Rifle Area, Colorado, Parts of Garfield and Mesa Counties Plasticit y index 10-15-2 0 15-23-3 0 25-28 5-8 1 0 -30 5-8 -10 10-15-2 0 5-8 -10 Liquld limit L-R-H 30-35 -40 30-35 -40 40-48 -55 25-28 -30 25-28 -30 30-35 -40 25-28 -30 Percentage passing sieve number- 200 L-R-H 90-95-1 70-75- 00 80 70-75- 80 75-8s- 95 60-68- 75 60-68- 75 60-68- 75 70-75- 80 60-68- 75 40 L.R-H 90-95-1 00 90-95-1 00 85-90- 95 85-90- 95 85-90- 95 90-95-1 00 85-90- 95 10 L-R-H 1 00-1 00 -1 00 '100-100 -1 00 1 00-1 00 -1 00 1 00-1 00 -1 00 1 00-1 00 -100 I 00-1 00 1 00-1 00 -100-1 00 1 00-1 00 -100 1 00-1 00 -100 4 L-R-H 100-100 -1 00 100-100 -100 1 00-1 00 -1 00 100-100 -1 00 1 00-1 00 -100 I 00-1 00 -1 00 100-'100 -1 00 Pct Fragments 3-10 inches L-R-H 0-0-0 0-0-0 0-0-0 0-0-0 0-0-0 0-0-0 0-0-0 0-0-0 0-0-0 0-0-0 0-0-0 >10 inches L-R-H 0-0-0 0-0-0 0-0-0 0-0-0 0-0-0 Classification AASHTO CL A-6 A-6 A-7 CL, CL- ML A-4 A-4 A-4 A-6 A-4 Unified CL CH, CL CL, CL- ML cL, cL- ML CL CL, CL- ML USDA texture In 0-8 Clay loam 8-21 Clay loam 21-60 Clay Loam Loam Loam Clay loam Loam Depth A 0-1 7 17-60 o-4 4-28 28-60 Hydrolo gic group 29-Heldt clay loam, 3 to 6 percent slopes Heldt 90 c c Pct. of map unit 85 85 Map unit symbol and soil name 56-Potts loam, 6 to 12 percent slopes 20 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. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/3 1 . Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18,2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 1 8. http:/iwww. nrcs.usda. gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs1 42p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soilsurveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:/i www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=n rcs142p2_053577 Soil Survey Staff. 2010. Keys to soiltaxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/poftal/nrcs/detail/soils/ h omei ?cid = n r cs1 42p2 _O 5337 4 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/land use/rangepasture/?cid=stelprdbl 043084 21 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-Vl. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soilsiscientists/?cid=nrcs1 42p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. hltptl www.nrcs.usda.gov/l nterneUFSE_DOCUMENTS/n rcsl 42p2-052290.pdf 22 EXHIBIT B CTL Thompson Soils Report ffi CTL I THOMPSON @ GEOTECHNICAL ENGINEERING INVESTIGATION BURKETT RESIDENCE TRACT 8, ANTLERS ORCHARD DEVELOPMENT GARFIELD COUNTY, COLORADO Prepared For: BOB BURKETT 384 Jenny Place New Castle, CO 81647 Attention: Bob Burkett Project No, GS06431.000-120 February 5,2020 234Cenler Drive I Glenwood Springs, Colorado 81601 Telephone: 970-945-2809 Fax: 970-945-741 1 ffi TABLE OF CONTENTS scoPE....... SUMMARY OF CONCLUSIONS.... SITE CONDITIONS PROPOSED CONSTRUCTION ............ GEOLOGIC COND1T|ONS................... suBsuRFAcE coNDtTloNS............,, SITE EARTHWORK....,... Excavations Subexcavation and Structural Fi|l...... Foundation Wall Backfi ll FOUNDAT|ONS..,........... SLAB-ON.GRADE CONSTRUCTION ., FOUNDATION WALLS,.. SUBSURFACE DRAINAGE.............,..... SURFACE DRAINAGE. CONCRETE CONSTRUCTION OBSERVATIONS,.", STRUCTURAL ENGINEERING SERVICES ........ GEOTECHNICAL RISK.. LrMtTAT|ONS,...........,.,. FIGUREl-VICINITYMAP FIGURE 2 _ AERIAL PHOTOGRAPH FIGURE 3 - SUMMARY LOGS OF EXPLORATORY BORINGS FIGURE 4 - SWELL_ CONSOLIDATION TEST RESULTS FIGURE 5 - GRADATION TEST RESULTS FIGURE 6 - FOUNDATION WALL DRAIN CONCEPT TABLE I- SUMMARY OF LABORATORY TESTING BOB BURKETT BURKETT RESIDENCE PROJECT NO. cS06431.000-t20 1 'l 2 3 3 4 5 E o 7 I o 10 11 12 12 13 13 14 ffi SCOPE This report presents the results of our geotechnical engineering investiga- tion for the Burkett Residence proposed on Tract 8, Antlers Orchard Develop- ment in Garfield County, Colorado. The scope of our geotechnical engineering investigation was set forth in our Proposal No. GS 19-0290. our report was pre- pared from data developed from our field exploration, laboratory testing, engi- neering analysis, and our experience with similar conditions. This report includes a description of the subsurface conditions found in our exploratory borings and presents geotechnical engineering recommendations for design and construction of foundations, floor systems, below-grade walls, subsurface drain systems, and details influenced by the subsoils. A summary of our conclusions is below. SUMMARY OF CONCLUSIONS Subsurface conditions encountered in our exploratory borings were about 2 inches of topsoil and 7 feet to 14 feet of predominanfly clayey to silty sand underlain by clayey to silty gravel. Practical au- ger refusaloccurred on bedrock fragments at a depth of 1b feet in allthree borings. Free groundwater was not found in our explora- tory borings at the time of drilling, Based on our field and laboratory data from the site, and our engi- neering experience, we judge the undisturbed natural soils at the site possess potential for moderate amounts of differential move- ment when wetted under building loads. The proposed residence and barn can be constructed on footing foundations, provided the soils below the entire areas of the building footprints are subexca- vated to a depth of at least 3 feet. The excavated soils can be mois- ture-treated and replaced as densely-compacted, structural fill. Recommendations for the subexcavation process and design crite- ria for footings are in the report. Slab-on-grade floors are planned in basement and garage areas of the residence. The barn floor will also be a slab. After the recom- mended subexcavation and recompaction process is accomplished below the entire building footprints, we anticipate good peformance 1 2 3 BOB BURKETT BURKETT RESIDENCE PROJECT NO. G806431.000-{ 20 1 ffi of slabs-on-grade supported by an at least 3-foot thickness of densely-compacted, structural fill. Below-grade areas in the buildings should be provided with perime- ter foundation drains to mitigate potential for subsurface wetting. Surface drainage should be designed to rapidly convey surface wa- ter away from the buildings, SITE CONDITIONS The Burkett Residence is proposed on Tract 8, Antlers Orchard Develop- ment in Garfield County, Colorado. A vicinity map with the location of the site is shown on Figure 1. The lot is a 10.417-acre parcel accessed by County Road 237 at the east. An aerial photograph of the site is shown on Figure 2. A natural drainage swale trends down to the south in the eastern part of the property. Ground surface at the site generally slopes down to the southeast at grades less than 10 percent. Much of the property was likely flood'irrigated in the past. Veg- etation consists of mostly grasses and weeds. Several inches of snow covered the ground at the time of our subsurface investigation A photograph of the site at the time of our exploratory drilling is below. BOB BURKETT BURKETT RESIDENCE PROJECT NO. GS06431.000-l 20 4 2 ffi PROPOSED CONSTRUCTION We were provided with preliminary architectural plans by Royal Oak De- sign (dated My 13, 2019). The plans indicate the residence will be a one and two-story, wood-framed building with a basement leveland an attached garage. Slab-on-grade floors are proposed in basement and garage areas. A barn with a slab-on-grade floor is also proposed. Maximum excavation depths to attain foun- dation elevations for the residence will likely be on the order of 10 feet. We ex- pect excavation depths of less than 5 feet to obtain foundation depths for the barn. Typical foundation loads for this type of construction are about 1,000 to 3,000 pounds per linear foot of foundation wall with maximum 50-kip interior col- umn loads. We should be provided with more detailed construction plans, when available, so that we can provide geotechnical/geo-structural engineering input, GEOLOGIC CONDITIONS As part of our geotechnical engineering investigation, we reviewed map- ping by the U.s. Geological survey (usGS) titled, "Geology Map of the sirt Quadrangle, Garfield county, colorado", by shroba and scott (dated 2001). The mapping indicates the overburden soils below most of the subject property con- sist of eolian loess deposits over pediment deposits that likely consist of the Shire Member of the Wasatch Bedrock Formation. The eolian loess deposits are prone to erosion and hydrocompaction. Undivided alluvium and colluvium de- posits are in the area of the drainage swale in the east part of the property. The Shire Member is described as consisting of intervals of claystone, mudstone, and siltstone interbedded with minor lenses of sandstone. Subsoils encountered in our exploratory borings drilled at the site are consistent with the loess over pedi- ment shown on the geologic mapping. BOB BURKETT BURKETT RESIDENCE PROJECT NO. GS0543t.000-1 20 3 ffi SUBSURFACE CONDITIONS Subsurface conditions at the site were investigated by drilling three explor- atory borings (TH-1 through TH-3) at the approximate locations shown on Figure 2. subsoils encountered in our borings were logged by our engineer, who ob- tained samples of the soils for laboratory testing. A photograph taken during drill- ing operations is below. Subsoils encountered in our exploratory borings were about 2 inches of topsoil underlain by clayey to silty gravel andT to 14 feet of predominately clayey to silty sand underlain by clayey to silty gravel and fragments of claystone, silt- stone, and sandstone bedrock. Practical auger refusal occurred on bedrock frag- ments at a depth of 15 feet in all three borings. Free groundwater was not en- countered in the borings at the time of drilling. PVC pipe was placed in TH-2 to facilitate future checks of groundwater. Graphic logs of the soils encountered in our exploratory borings are shown on Figure 3. Subsoil samples from our exploratory borings were returned to our labora- tory where field classifications were checked and representative samples were BOB BURKETT BURKETT RESIDENCE PROJECT NO. cS06431.000-120 4 ffi selected for pertinent testing. Two samples soils selected for one-dimensional, swell-consolidation testing exhibited 1.0 percent consolidation and 0.3 percent swell when wetted under an applied load of 1,000 psf. Swell-consolidation test results are shown on Figure 4. Two samples of the soils selected for gradation analysis contained 1 to 29 percent gravel, 46 to 47 percent sand, and 24 to s3 percent silt and clay (passing the No. 200 sieve). Gradation test results are shown on Figure 5. Engineering index testing performed on one sample of clayey sand indicated a liquid limit of 36 percent and a plasticity index of 13 per- cent. Laboratory testing results are summarized on Table l. SITE EARTHWORK Excavations Excavations at the site to construct the proposed residence and barn can be accomplished using conventional, heavy-duty excavating equipment. From a "trench" safety standpoint, sides of excavations need to be sloped or braced to meet local, state and federal safety regulations. We expect the soils encoun- tered in excavations will classify as Type B or Type c soils based on osHA standards governing excavations. Temporary excavation slopes that are not re- tained should be no steeper than 1 to 1 (horizontal to vertical) in Type B soils and 1.5 to 1 in Type C soils. Contractors are responsible for maintaining safe exca- vations. Free groundwater was not encountered in our exploratory borings. We do not anticipate excavations for construction of the building foundations will pene- trate the free groundwater table. We recommend excavations be sloped to grav- ity discharges or to temporary sumps where water from precipitation can be re- moved by pumping. BOB BURKETT BURKETT RESIOENCE PROJECT NO. cS06431.000-120 5 ffi Subexcavation and Structural Fill Based on our field and laboratory data from the site, and our engineering experience, the soils at the site possess potential for moderate amounts of differ- ential movement when wetted under building loads. To reduce potential risk of differential movement, we recommend subexcavation of the soils below the en- tire building footprints to a depth of at least 3 feet below footing and slab eleva- tions and replacement with densely-compacted, structural fill. The subexcavation process should extend at least 1 foot beyond the perimeter of the building foot- prints. The subexcavated soils, free of organic matter, debris and rocks larger than 3 inches in diameter can be re-used as structuralfill. The structural fill soils should be moisture-conditioned to within 2 percent of optimum moisture content and placed in loose lifts of 8 inches thick or less. Structural fill should be com- pacted to at least 98 percent of standard Proctor (ASTM D 6gs) maximum dry density. Moisture content and density of structural fill should be checked by a representative of our firm during placement, Observation of the compaction pro- cedure is necessary. Foundation Wall Backfill Proper placement and compaction of foundation backfill is important to re- duce infiltration of surface water and settlement of backfill. The soils excavated from the site can be used as backfill, provided they are free of rocks larger than 3-inches in diameter, organics, and debris, Backfill soils should be moisture-con- ditioned to within 2 percent of optimum moisture content placed in loose lifts of approximately 10 inches thick or less and compacted, Thickness of lifts will likely need to be about 6 inches if there are small confined areas of backfill, which limit the size and weight of compaction equipment. BOB BURKETT BURKETT RESIDENCE PROJECT NO. GSo6431.000-120 6 ffi Backfill should be compacted to at least 95 percent of maximum standard Proctor (ASTM D 698) dry density. Moisture content and density of the backfill should be checked during placement by a representative of our firm. Observation of the compaction procedure is necessary. FOUNDATIONS Based on our field and laboratory data from the site, and our engineering experience, the undisturbed natural soils at the site possess potential for moder- ate amounts of differential movement when wetted under building loads. We judge the residence and barn can be constructed on footing foundations, pro- vided the soils below the entire areas of the building footprints are subexcavated to a depth of at least 3 feet below planned bottom of footing elevations. The ex- cavated soils can be moisture-treated and reused to build mats of densely-com- pacted, structural fill below the buildings. Structural fill should be processed, placed, and compacted in accordance with recommendations in the Subexcava- tion and Structural Fill section. We expect the subexcavation and structuralfill process will result in good performance of footings, however, some risk of differential settlement will still ex- ist. lt will be criticalto adhere to recommendations in the SUBSURFACE DRAINAGE and SURFACE DRAINAGE sections, Recommended design and construction criteria for footing foundations are presented below. The residence and barn can be constructed on footing foundations supported by an at least 3-foot thickness of moisture-treated, densely-compacted structural fill soils in accordance with the Subexcavation and Structural Fill section. SOB BURKETT SURKETT RESIDENCE PROJECT NO. c306431.000-r20 1 7 ffi 2 3 Footings on the structuralfill can be sized using a maximum allowa- ble bearing pressure of 2,000 psf. continuous wall footings should have a minimum width of at least 16 inches. Foundations for isolated columns shourd have minimum dimensions of 24 inches by 24 inches. Larger sizes may be re- quired, depending upon foundation loads. Grade beams and foundation walls should be werr reinforced, top and bottom, to span undisclosed loose or soft soil pockets. we rec- ommend reinforcement sufficient to span an unsupported distance of at least 12feet. The soils under exterior footings should be protected from freezing. we recommend the bottom of footings be constructed at a depth of at least 36 inches below finished exterior grades. The Garfield county building department should be consulted regarding required frost protection depth. SLAB.ON-GRADE CONSTRUCTION Slab-on-grade floors are proposed in basement and garage areas of the residence. The barn floor will also be a slab-on'grade. Soils below the entire ar- eas of the building footprints should be subexcavated to a depth of at least 3 feet below planned bottom of slabs. The excavated soils can be moisture-treated and reused to build mats of densely-compacted, structural fill below the buildings. A 1-foot thickness of structural fill is recommended below exterior slabs and flat- work. Sub-excavation and structuralfill should be in accordance with the recom- mendations in the subexcavation and structural Fill section. We expect the subexcavation and structural fill process will result in good performance of slabs, however, some risk of differential settlement will still exist. BOB SURKETT BURKETT RESIDENCE PROJECT NO. cS06431.000-120 4. 5 I ffi It will be criticalto adhere to recommendations in the SUBSURFACE DRAINAGE and SURFACE DRAINAGE sections. We recommend the following precautions for slab-on-grade construction at this site. slabs should be separated from exterior walls and interior bearing members with slip joints which allow free vertical movement of the slabs. The use of underslab plumbing should be minimized, Underslab plumbing should be pressure tested for leaks before the slabs are constructed. Plumbing and utilities which pass through slabs should be isolated from the slabs with sleeves and provided with flexibre couplings to slab supported appliances. Exterior patio and porch slabs should be isolated from the buirding These slabs should be well-reinforced to function as independent units. Movements of these slabs should not be transmitted to the building. Frequent controljoints should be provided, in accordance with American Concrete lnstitute (ACl) recommendations, to reduce problems associated with shrinkage and curling. FOUNDATION WALLS Foundation walls which extend below-grade should be designed for lateral earth pressures where backfill is not present to about the same extent on both sides of the wall, such as adjacent to basement and crawl space areas. Many factors affect the values of the design lateral earth pressure. These factors in- clude, but are not limited to, the type, compaction, slope and drainage of the backfill, and the rigidity of the wall against rotation and deflection. For a very rigid wallwhere negligible or very little deflection will occur, an "at-rest" lateral earth pressure should be used in design. For walls that can de- flect or rotate 0.5 to 1 percent of wall height (depending upon the backfill types), BOB BURKETT BURKETT RESIDENCE PROJECT NO. G300431.000-l 20 1 2 3 4 9 ffi lower "active" lateral earth pressures are appropriate. Our experience indicates typical below-grade walls in residences deflect or rotate slightly under normalde- sign loads, and that this deflection results in satisfactory wall performance. Thus, the earth pressures on the walls will likely be between the "active" and "at-rest" conditions. lf the on-site soils are used as backfill and the backfill is not saturated, we recommend design of below-grade walls at this site using an equivalent fluid den- sity of at least 50 pcf. This value assumes deflection; some minor cracking of walls may occur. lf very little wall deflection is desired, a higher design value for the "at-rest" condition is appropriate using an equivalent fluid pressure of 60 pcf. SUBSURFACE DRAINAGE Water from surface precipitation, snowmelt, and irrigation frequently flows through relatively permeable backfill placed adjacent to a residence and collects on the surface of less permeable soils occurring at the bottom of foundation ex- cavations. This process can cause wet or moist conditions in below-grade areas, such as basements and crawl spaces, after construction. lt can also result in subsurface wetting below the building, which can cause volume changes in the soils and differential building movement and associated damage. We recommend that exterior foundation drains be installed around the pe- rimeters of the basement and other below-grade areas of the buildings. The ex- terior foundation drains should consist of 4-inch diameter, slotted, PVC pipe en- cased in free-draining gravel. A prefabricated drainage composite should be placed adjacent to foundation walls, Care should be taken during backfill opera- tions to prevent damage to drainage composites. The drains should lead to posi- tive gravity outlets, or to sump pits where water can be removed by pumping. Gravity outlets should not be susceptible to clogging or freezing. lnstallation of clean-outs along the drain pipes is recommended. The foundation drain concept is shown on Figure 6. BOB BURKETT BURKETT RESIDENCE PROJECT NO. GS0643t.000-120 10 TF SURFACE DRAINAGE Surface drainage is critical to the performance of foundations, floor slabs, and concrete flatwork. Surface drainage should be designed to provide rapid runoff of surface water away from the residence and barn. Proper surface drain- age and irrigation practices can help control the amount of surface water that penetrates to foundation levels and contributes to settlement or heave of soils and bedrock that support the foundation and slabs-on-grade. Positive drainage away from the foundations and avoidance of irrigation near the foundation also help to avoid excessive wetting of backfill soils, which can lead to increased backfill settlement and possibly to higher lateral earth pressures, due to in- creased weight and reduced strength of the backfill. We recommend the follow- ing precautions. The ground surface surrounding the exterior of the residence and barn should be sloped to drain away from the building in all direc- tions. We recommend a minimum constructed slope of at least 12 inches in the first 10 feet (10 percent) in landscaped areas around the buildings, where practical. Backfill around the foundation walls should be moistened and com- pacted pursuant to recommendations in the Equndation Wall Back- fillsection. Roof downspouts and drains should discharge well beyond the rim- its of all backfill. Splash blocks and/or extensions should be pro- vided at all downspouts so water discharges onto the ground be- yond the backfill. We generally recommend against burial of down- spout discharge. Where it is necessary to bury downspout dis- charge, solid, rigid pipe should be used, and it should slope to an open gravity outlet. lrrigation should be limited to the minimum amount sufficient to maintain vegetation; application of more water will increase likeli- hood of slab and foundation movements. Landscaping should be carefully designed and maintained to minimize irrigation. plants placed close to foundation walls should be limited to those with low BOB BURKETT BURKETT RESIDENCE PROJECT NO. GE06431.000-l 20 1 2 3 4 11 ffi moisture requirements. lrrigated grass should not be located within 5 feet of the foundation. sprinklers should not discharge within 5 feet of the foundation. Plastic sheeting should not be placed be- neath landscaped areas adjacent to foundation walls or grade beams. Geotextile fabric will inhibit weed growth yet stiil ailow natu- ral evaporation to occur. CONCRETE Concrete in contact with soil can be subject to sulfate attack. We meas- ured a water-soluble sulfate concentration of 0.1 1 percent in one sample of the soils from the site. For this level of sulfate concentration, ACI 332-08, Code Re- quirements for Residential Concrefe, indicates concrete shall be made with ASTM 6150 Type ll cement, or an ASTM C595 or C1157 hydraulic cement meet- ing moderate sulfate-resistant hydraulic cement (MS) designation. Alternative combination of cements and supplementary cementations materials such as Class F fly ash, shall be permitted with accurate test records for sulfate durability. ln our experience, superficial damage may occur to the exposed surfaces of highly-permeable concrete, even though sulfate levels are relatively low. To control this risk and to resist freeze-thaw deterioration, the water-to-cementitious materials ratio should not exceed 0.50 for concrete in contact with soils that are likely to stay moist due to surface drainage or high-water tables. concrete should have a total air content ol 6% +l- 1.5o/0. We recommend all foundation walls and grade beams in contact with the subsoils be damp-proofed. CONSTRUCTION OBSERVATIONS we recommend that crl I Thompson, lnc. be retained to provide con- struction observation and materials testing services for the project. This would allow us the opportunity to verifi7 whether soil conditions are consistent with those found during this investigation. lf others pedorm these observations, they must accept responsibility to judge whether the recommendations in this report remain appropriate. Our experience indicates it is beneficialto projects, from economic SOB BURKETT BURKETT RESIDENCE PROJECT NO. GS0643t.000-120 12 ffi and practical standpoints, when there is continuity between engineering consulta- tion and the construction observation and materials testing phases. STRUCTURAL ENGINEERING SERVICES CTL I Thompson, lnc. is a full-service geotechnical, structural, materials, and environmental engineering firm. Our services include preparation of struc- turalframing and foundation plans. We can also design earth retention systems. Based on our experience, crl I Thompson, lnc. typically provides value to pro- jects from schedule and economic standpoints, due to our combined expertise and experience with geotechnical, structural, and materials engineering. we would like the opportunity to provide a proposalfor structural engineering ser- vices on your project. GEOTECHNICAL RISK The concept of risk is an important aspect of any geotechnical evaluation. The primary reason for this is that the analytical methods used to develop ge- otechnical recommendations do not comprise an exact science. The analytical tools which geotechnical engineers use are generally empirical and must be tem- pered by engineering judgment and experience. Therefore, the solutions or rec- ommendations presented in any geotechnical evaluation should not be consid- ered risk-free and, more importantly, are not a guarantee that the interaction be- tween the soils and the proposed structure will perform as desired or intended. What the engineering recommendations presented in the preceding sections do constitute is our estimate, based on the information generated during this and previous evaluations and our experience in working with these conditions, of those measures that are necessary to help the building perform satisfactorily. This report has been prepared for the exclusive use of the client for the purpose of providing geotechnical engineering design and construction criteria for the proposed residence. The information, conclusions, and recommendations SOB BURKETT BURKETT RESIDENCE PROJECT NO. cS06431.000-1 20 13 ffi presented herein are based upon consideration of many factors including, but not limited to, the type of structures proposed, the geologic setting, and the subsur- face conditions encountered. The conclusions and recommendations contained in the report are not valid for use by others. Standards of practice continuously change in the area of geotechnical engineering. The recommendations provided in this report are appropriate for about three years. lf the proposed project is not constructed within three years, we should be contacted to determine if we should update this report. LIMITATIONS Our exploratory borings provide a reasonably accurate picture of subsur- face conditions at the site. Variations in the subsurface conditions not indicated by the borings will occur. Our representative should be called to observe the subexcavation process and test moisture and density of structural fill during placement. This investigation was conducted in a manner consistent with that level of care and skill ordinarily exercised by geotechnical engineers currently practicing under similar conditions in the locality of this project. No warranty, express or im- plied, is made. lf we can be of further service in discussing the contents of this report, please call. cTL ITHOMPSON, tNC Reviewed by; ./' 'rui t )f /u/.n- a-/ 'y'/r' t'L'' Ryan W. DeMars, E.l.T Staff Engineer mes D. Kellogg, P.E. RWD:JDK:ac cc: Viaemailtoalltecbob@qmail.com BOB BURKETT BURKETT RESIDENCE PROJECT NO. GS06431.000-{ 20 fr0 5 38298 ion Manager 14 ffi 0 2000 SCALE: 7' - 2olOO' Bob Burkett BurlGtt Fbclctonco ProJect No. GSO6431 .OOO-1 20 NOTE: IMAGE FROM GOOGLE EARTH Vicinity Map -- Flg. I LEGEND TH-1o ffiAPPROXIMATE LOCATION OF EXPLORATORY BORING APPROXIMATE PROPERTY BOUNDARY NOTE: IMAGE FROM GOOGLE EARTHo100200 SCALE: 1' = 2OO' .:,: & Bob Burkeft Budctt Rcsldonc. ProJect No. GSO6431 .OOO-1 20 Aerial Photograph Flg. 2 TH-1 Tt-t-2 trTHs 10 17t1? TOPSO|L, CtAy. StLTy, SANDY, cM\tEL MOIST, LTGHT BRoIAIN. SAT{D, CLAYEY. SILTY, T.ENSES OF SAIEY CIAY, MEDITN DENSE TO DEI{SE $.!iGIITLYnolsr, BRoutN. (scsir, cl.-ltl) oRlvE sqrple ltE syll,tsoL 5{rr9 tNDtc{ATES sO 8t_&t S OF A t4spotND tlAilt ER FAtIJtlS 30 INCTGS yIERE REqXRED TO DRn E A aSJNCH O.D, SArFt€R 9 &G.|ES. GM\IEI- CI.AYEY. SILTY, TEI{SES OFSATTDY CI.AY, FRAGIEifTS OFCLAYSIOOE. SITSToNE AND SANOSTON{€, OE|{SE rO\rERy DENSE USr, LEril€sot rat- (cc.s00 LEGEN} 0 5 15 20 w E E F f rnncncer- oR[.t RERJsAL. l{oTEs: 1. E@LORATORYBORiGS|VERE DR|IIED ONJAI,RIARYO, m2oWTIH4{EH D|A}|ETER,sor_nlslatftlGERA,f,)ATR|CK-$q$[rED ORI.IRtG. mE GFO|${DIuA.]ERWAS |NOT E}TOUiITEREDF{ q,JRAORNGSATr}ETIIFOF DRT-LING. E P\ilC PPE\{ASPI.ACED INT}+2TO FACILTTAIEFuNNEC}FCI(SOFCrcIJilI{ATER 3. LOCANO}F OF EXPLORATORY BOR'ISS ARF APPROIOMATE 4. EELORATORY BORNGS ARE SI,B.ECT]O f}€ B(PI,!I{A:IIOilS, T,HTAIIOT{S A'S CONCLT'SIONS @NTANED N Nl}S R€PORr. I I I BOA BUR(ETT BURI(ETT RESIDENCE PROJECTNO. GSOBI31 -00G120 SI'ItiIilARY LOGS OF EXPLORATORY BORIT{GS FIG. 3 0 =tr -1 -2 z-3o u,z ;! a xlrl sz-so6olll -atr o- EoO-7 0.1 1.0 APPLIED PRESSURE - KSF Somple of SAND, CLAYEY, SILTY (SO-SM) From TH-3 AT 4 FEET 10 DRY UNITWEIGHT= MOISTURE CONTENT= 10 DRY UNITWEIGHT= MOISTURE CONTENT= 108 100 PCF % 3 2 6.2 122 100 PCF % 0zoaz-l 4xllJ-z sz9-soo IU E,L4 =oo -5 0.1 APPLIED PRESSURE. KSF 1.0 Somple of From TH.3 AT 14 FEET SAND, CLAYEY, SILTY BOB BURKETT BURKETT RESIDENCE PROJECT NO. cS06431.000.120 8.1 Swell Consolidation Test Results 1 ) ADDITIONAL COMPRESSION UNDER CONSTANT PRESSURE DUE TO WETTING( { \ \ ) EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING \ \\ i I I (sc-sM) trlc a ffi SANDS GRAVELcLAY (PLASTTC) TO StLT (NON-pl-ASTtC) FINE MEDIUM COARS FINE COARSE COEBLES HYDROMETER ANALYSIS SIEVE ANALYSIS --l l=, --t : =---_- - = =-: -r.,--l l::]-J -I_-i l--.::::: _:___: =--.._ -= .-_---___:::: I --... .':_ :::::--: =----: ] -__l 2roqo .<60 Fz 350et!a4o o UJz Fud FzruotUq 76.2 127 200 152 '4 90 80 100 .001 0.002 .005 ,009 ,019 .037 9.52 19.1 36.1 5"6" I' TIME REAOINGS U.S. STANDARD SERIES 60 MtN. 19 MtN. 4 MtN. 'l MtN, .200 .100 ,50 .40 .30 .16 .10 .8 CLEAR SOUARE OPENINGS 3t8" 314" 1% 3" 30 20 10 0 .074 .'t49 .257 .590 1,19 2.O 2.38 4.78 o.42 DIAMETER OF PARTICLE IN MILLIMETERS 60 70 80 90 100 0 10 20 JU 40 50 25 HR, 7 HR, 45 MtN. 15 MtN. Somple of sAND, cLAyEy (Sc)FTom TH-1AT9FEET Somple of CLAy, StLTy, SANDy (CL-ML)From TH-2AT 14FEET BOB BURKETT BURKETT RESIDENCE PROJECT NO. GS06431.000-120 GRAVEL 1 Yo SAND SILT & oLAY 53 o/o LIQUID LtMtT PLASTICITY INDEX Gradation Test Results GRAVEL SILT & CLAY PLASTICITY INDEX % SAND % LIQUID LIMIT24 47% % o/o 29 46% o/o o/o SANDS GRAVELcLAY (PLASTTC) TO StLT (NON-PLAST|C) FINE MEDIUM COARS FINE COARSE COSBLES ANALYSIS --._t,--t *+ -=F -::----:-- = -_:i-_-_- --:l : :::=_l. '____t__, __-,-- i_..-,_t.,-/---- *_l_._.-_.'--t----- -l-_:-_l__- __ - -.. --t------_-i- - ----:l -----_,-____l_-_t______-_-:::-r-:::::-:-___l__t-..,.. -t l------ __t____'l'--..--_.----l------ -_t ___- -,-_,t-___-_-___,_--.____-t___-t--..-= r:l .- _____]__ ,_ _t._ .____t __---t-,- -:l--::-J-:: 100 90 80 (Jtoz6a f60 Fz 350e,Uo.lo 30 20 10 0 .074 .149 .297 ,590 1.19 2.0 2.38 4.76 9.52 19.1 36.1 76.2 127 2oO0.42 - - '-isf-- OIAMETER OF PARTICLE 'N MILLIMETERS '4 6' 0 oUz FUE '10 20 30 40 50 60 70 80 90 100.001 0.002 .005 .009 .019 .037 TIME READINGS U.S. STANDARD SERIES 80 MtN. 19 MtN. 4 MrN, 1 MtN. .200 .100 .50 .40 .30 .16 .10 '8 CLEAR SOUARE OPENINGS 3/8" 314' 1Y," 3" 5'6' 25 HR. 7 HR. 45 MtN. 15 MtN. FIG. 5 ffi E I a SLOPE osltA COI/ER ENNRE OF CRA\GL WIIH GEOTEXNIE FABRIC 140N OR ENCASE PIPE IN GRAVEL DOEND AI.ID AT I.EAST EiMRE TRENCH Bob Burkett PER )xn DRAIMCE @MPOSm (U|RADRATN So00 oR EAUMAT.B{I) 2-S' SHEENNC EELOW-GRADE |Vfl.r suP ,rotNT FOOTING OR PAD ATTACH PI.ASIIC TO FOUNDATION lilNtMuil BEYONDOR 1:1 SLOPE FROM BOTTOM OF FOONNG (lvlllcHn/ER S Cnemn) 1-lNg[_DtAtrErER PERFORATED RtGtD DM|N ptpE. THE ptpE sHour,.D BE pt.ncED n a rnorcn dryni 4 9roPE gf Ar tE sr vB-tNcH DROP PER FOOT OF DRNN. 1/2'TO t-1/2'WASHE) GRAVEL NTERruY TO FOOTINOt/2 H$c'fi OF FOOnNC. Rtr WTTH GRA\GL NOTE THE BOTTOM OF THE.IRAIN_9IOUID BE AT |gg.r 2 NCHS BETOTT BOTTOM OFlgq[Nc -4r rHE HrcHEsr_ _Forur AirD sLopF rgu _irwAdit -to n -65iirvu- bivivnv'OUII.ET OR TO A SUMP WHERE WAilER EqI'I BE hEi,iiNb'Br'PLITNTE Foundation Wall Drain ConceptProJect No. GSO64gl.OOO-1 20 Ela A TABLE I SUMMARY OF LABORATORY TESTING PROJECT NO. cS06431.000-120 ffi PTION CLA NO.200 SIEVE 24 3J PERCENT SAND 46 PERCENT GRAVEL (o/o) 1 SOLUBLE SULFATES (o/o\ 0.1'l SWELL' (%l -1-0 ATTERBERG LIMITS PLASTICITY INDEX (%\ LIQUID LIMIT (%\ DRY DENSITY {PCF) MOISTURE CONTENT (%l 1 DEPTH (FEET) I EXPLORATORY BORING TH-2 TH-3 TH-3 'SWELL MEASURED WITH lOOO PSF APPLIED PRESSURE. NEGATIVE VALUE INDICATES COMPRESSION. Page 1 of 1 EXHIBIT C OWTS Drawing by SGM OWTS Design ond Detoils Gorfield Couniy, Colorodo Burkell Residence Troct 8, Aniler Orchord Development,Silt, CO M 200 8t601 INFILTMTOR SYSTEMS INC. QUICK4 STANDARD CHAMBER : /ffsP€cn@rcRrl 48i -----,_--- -_-+ GtrECNVE) 12' t-_ .'1..'.i, J' r::rjr .r:ii!.:Ji:::,ii:. r:,jj :r,: i:i:j r ' :1!. !:1- :j,!'r ' 4.!:i I QUICK4 CHAMBER 7yP|CAL |NSTALUT|ON DETAIL (Not to S@le) , .., 4- @{wAM PE. * _#- rgo&LPOLYLOK PRODUCT DETAIL I I I a NHd@tuws.Mdep } EWEfuMMfuQfufuM- I (m4 tos eNMw@) 6 ew uffi- @ tut) QUICK4 STANDARD MULTIPORT END CAP ..,-- tN-gtu tu1. ftP INFIL'fuIOE fuEX1-._&@18 CWER s/\/1 \ lgELq E AUAION 1/\ ir : ..-., ! J' IPE M@row '5-EEMIMffi 1250 GAL. SEPilC TANK Schemolic {or Permii ond Conslruction QUICK4 TRENCH DETAIL Garfield County Community Development Department 108 8tn street, Suite 401 Glenwood Springs, CO 81601 l970l94s-8212 www.garfield-countv.com SEWAGE DISPOSAL PERMIT CHECKLIST Permit applications can be obtained and submitted to the Garfield County Community Development Department located at 108 8th Street, Suite 401, Glenwood Springs, CO. See below for additional information. All applications are required to be submitted in person. PERMIT APPLICATION & SUBMITTAL REQUIREMENTS: . Completeapplication.o 1 Copy of a Site Plan that includes well, all streams, irrigation ditches and any water courses. Draw in your house, septic tank and system, detached garages and driveway. lf a change of location is necessary, you must submit a corrected drawing.o Engineered Systems will need a copy of soil evaluation/ perk rate and design for our records prior to final inspection. FEES: FEES ARE NOT REFUNDABLE. Payment is required at time of submittal. Make Gheck payable to: Garfield County Treasurer . Septic Permit for a New installation .$123.00 o Septic PermitforAlterationand/or Repair ..........$75.00 . SepticPerktest ..........$150.00 ATTACHMENTS:o Percolation Test lnstructions. . Recommended minimum requirements for Onsite Wastewater Treatment System (owrs). FINAL INSPEGTION:o When all components are in place, connected and ready to cover, request a final inspection by the County lnspector.. DO NOT backfill any part of the system prior to the inspection. o The initial fee covers the percolation test and one (1) inspection before cover up. Any additional percolation test will be charged at $150.00 each and additional inspections will be charged at $50.00 each. . Upon final approval, carefully cover the entire system. . Engineered Systems are inspected by the Engineer prior to backfill. A finalsealed letter by the Engineer is required to be submitted to Garfield County. As built drawings are required. ONSITE WASTEWATER TREATMENT SYSTEM (owrs) APPLICATION CHECKLIST (Applicant's Copy) PERCOLATION TEST I NSTRUCTIONS The successful operation of your septic system depends on the rate the soil in which your leach field will be installed will accept water. THIS lS CRITICAL - lf instructions are not followed completely, technician may not do the perk test and you will be charge a $50.00 fee for 2nd visit. The rate of absorption is called the percolation rate and it determines the size of the leach field needed for a particular flow of sewage and in some cases even determines the feasibility of the installation of a septic tank and leach field system. PERCOLATION TEST MUST BE DONE AT THE GROUND DEPTH WHERE ABSORPTION WILL TAKE PLACE. STANDARD LEACH FIELDS ARE INSTALLED THREE (3) FEET DEEP, SO THE THREE (3)PERCOLATION HOLES ARE DUG FOUR (4) FEET DEEP, AT LEAST TWENTY (20) FEET APART, IN A TRIANGULAR SHAPE. THE PERCOLATION TEST tS DONE lN THE BOTTOM ONE (1) FOOT OF THE HOLE. Post Hole It!$u Backhoe Hole Ios) sFPs ffir d-l Itu-l1rl dtt9 urf,\tr I' A posthole digger, auger or backhoe can be used to dig the percolation test holes. lf a back hoe is used, dig the backhoe hole 3 feet deep, with 2 steps or a ramp. Put a test hole 1 foot deep and 8 to 12 inches in diameter in the bottom. lnstallation of absorption areas (i.e. dnywells) deeper than 3 feet require the permission of the Environmental Health Department. All dry wells shall be designed by an Engineer registered in the State of Colorado. Saturation with water will affect the percolation rate, and since the system will be expected to operate when the soil is saturated with water,THE LOWER TEST HOLE MUST BE FILLED WITH WATER AT LEAST 8 HOURS BEFORE THE TEST AND ALLOWED TO STAND. More water wiII be needed to perform the percolation test, so AT LEAST 5 GALLONS OF WATER PER HOLE SHOULD BE ON HAND EN THE TE TISP AN 8 FOOT PROFILE HOLE IN THE LEACH F IFI D AREA IS REOLJIRED BY THE STATE OF COLORADO TO DETERMINE THE PROXIMITY OF GROUND WATER AND BEDROCK. One soil profile hole shall be dug to provide observation of the soil profile of the area of the soil absorption system The hole shall be prepared at least I feet deep. The hole may be terminated when ground water or bedrock is encountered. The hole shall be prepared in such a way as to provide identification of the soil profile 4 feet below the bottom of the soil absorption system. lf ground water is found in any perk or profile hole, an engineered system is required. Percolation rates lggfgthan 5 minutes per inch or $gglthan 60 minutes per inch will require an engineered system and/ or Board of Health approval. (Applicant's Copy) RECOMMENDED MINIMUM REQUIREMENTS FOR ONSITE WASTEWATER TREATEMENT SYSTEM (owTs) Before construction is started, the lnspector must be contacted for approval and detailed information concerning the proposed disposal system is needed. Higher standards than those which follow may be required in individual cases to assure attainment of the objective. Those objectives are to locate, construct and maintain onsitewastewatertreafnentsystems in such a mannerthat existing or contemplated water supplies will not become contaminated and so that sewage will not overflow the ground surface and result in a nuisance or health hazard. LIOUID CAPACITY O F TANK {GALLONSI Provide for use of automatic clothes washer and other water usi household A Dwelling on less than two acres, areas of high water tables, or areas with a percolation test rate faster than 1 inch in 5 minutes must have alternative sewage facilities, i.e., centralcollection, holding tanks, individual treatment, etc. EXEMPTION: Absorption areas may be allowed with percolation rates faster than 1 inch in 5 minutes provided the soil is a sandy texture and no water table problems are encountered. An Engineer is required. Slopes greater than 30% also require an Engineered System, Septic tank construction should be of concrete material that will resist deterioration and which can be made reasonably watertight. See code for septic tank specifications. lf the house sewer line is longer than 10 feet between house and septic tank, a clean-out Y should be installed outside as near as practical to the house_. Septic tanks should be inspected once a year and cleaned when necessary. Cleaning is recommended when space between the scum accumulation and sludge residue on the tank bottom is less than eighteen (18) inches. The Department recommends pumping a septic tank once every four (4) years, when a yearly inspection by the owner is not practical. Effluent screen is required in all new and replaced septic tanks, providing access to maintain effluent screen. a a a a a Number of Bedrooms Recommended Minimum Tank Capacity 1,000 gallons3 or less 1,250 qallons4 or less For each additional bedroom, add 250 gallons 1. Maximum lenqth of drainaoe line:l00linearfeet 18 inches 3, Minimum between trenches or 6 feet As level as possible 5. Minimum deoth rock under drain PVC:6" under PVC,2" over PVC 6. Minimum depth of cover over distribution lines:12 inches Variable7, Maximum depth of cover over distribution lines: 8. Minimum qrade of house sewer:1 18lol/t" per linear ft. 20 feet9. Minimum distance of sewaoe disposal svstem from dwellinq: 10, Minimum distance of septic tank from dwelling 5 feet 100 feet 12. Minimum distance of tank to a well 50 feet 50 feet 14, Minimum distance from septic tank and disposalfield to property lines 10 feet for drywell 10 feet for leach field. 4 inch diameter15. Minimum sewer pipe and distribution pipe: (Applicant's Copy)