Example: bachelor of science

Soil Potential Ratings - USDA

United States Department of Agriculture Natural Resources Conservation Service 344 Merrow Road, Suite A * Tolland, Connecticut 06084-3917 * (860) 871-4011 * soil Potential Ratings Subsurface Sewage Disposal Systems for Single Family Residences STATE OF CONNECTICUT. February, 2009. TABLE OF CONTENTS. Page INTRODUCTION .. 1. PURPOSE .. 1. DEFINITION .. 1. soil Potential Ratings .. 2. USE CONSTRAINTS .. 2. PERFORMANCE STANDARD .. 2. RATING CLASSES .. 3. EVALUATION CRITERIA .. 4. soil Potential Ratings BY MAP UNIT .. 6. CORRECTIVE MEASURES .. 6. SOME SITE CONDITIONS AND DESIGN CONSIDERATIONS. NOT REPRESENTED IN THE Ratings .. 7. REFERENCES .. 37. TABLES. TABLE 1 Evaluation Factors .. 9. TABLE 2 Corrective Measures for Slope .. 10. TABLE 3 Corrective Measures for soil Percolation Rates .. 11. TABLE 4 Saturated Hydraulic Conductivity and Percolation Rate .. 12. TABLE 5 Corrective Measures for Depth to Seasonal High Water Table .. 13.

2 Soil Potential Ratings Soil potential ratings are classes that indicate the relative quality of a soil for a particular use compared to other soils in a given area, in this case the state of

Tags:

  Soil, Potential, Ratings, Soil potential ratings, Soil potential ratings soil potential ratings

Information

Domain:

Source:

Link to this page:

Please notify us if you found a problem with this document:

Other abuse

Transcription of Soil Potential Ratings - USDA

1 United States Department of Agriculture Natural Resources Conservation Service 344 Merrow Road, Suite A * Tolland, Connecticut 06084-3917 * (860) 871-4011 * soil Potential Ratings Subsurface Sewage Disposal Systems for Single Family Residences STATE OF CONNECTICUT. February, 2009. TABLE OF CONTENTS. Page INTRODUCTION .. 1. PURPOSE .. 1. DEFINITION .. 1. soil Potential Ratings .. 2. USE CONSTRAINTS .. 2. PERFORMANCE STANDARD .. 2. RATING CLASSES .. 3. EVALUATION CRITERIA .. 4. soil Potential Ratings BY MAP UNIT .. 6. CORRECTIVE MEASURES .. 6. SOME SITE CONDITIONS AND DESIGN CONSIDERATIONS. NOT REPRESENTED IN THE Ratings .. 7. REFERENCES .. 37. TABLES. TABLE 1 Evaluation Factors .. 9. TABLE 2 Corrective Measures for Slope .. 10. TABLE 3 Corrective Measures for soil Percolation Rates .. 11. TABLE 4 Saturated Hydraulic Conductivity and Percolation Rate .. 12. TABLE 5 Corrective Measures for Depth to Seasonal High Water Table .. 13.

2 TABLE 6 Corrective Measures for 14. TABLE 7 Corrective Measures for Depth to 15. TABLE 8 soil Potential Ratings Map Unit .. 16. TABLE 9 Map Units Grouped by Potential Rating .. 30. The 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 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, , Washington, 20250- 9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD).

3 USDA is an equal opportunity provider and employer. 0. Introduction The soil Survey of the State of Connecticut is a modern soil survey, unifying the separate eight county soil legends to a single statewide legend, incorporating current soil taxonomy and standards, addressing land use changes and urbanization, and compiled onto planimetric orthophoto base. The soil survey provides information on the location and characteristics of various kinds of soils within the state. The soil survey report also contains interpretations or Ratings of the soils for various land uses. The interpretations are based on the soil properties that affect the intended use. These interpretations are dynamic. They must be periodically revised to reflect improved soils data, new technology and the needs of the soil survey report users. Purpose The purpose of this document is to update and expand the interpretations in the soil survey report for subsurface sewage disposal systems (SSDS).

4 These updated interpretations are in the form of soil potentials, which are interpretive Ratings that stress soil suitability. The soil Potential Ratings may be used to determine the relative suitability of soils when installing a SSDS as well as possible ways soil limitations may be overcome.*. These soil potentials were developed for planning purposes and are not intended as recommendations for soil use. The information presented here will be useful to groups or individuals involved with urban development such as local officials, builders, engineers, sanitarians, realtors, homebuyers, and other decision makers. It may also be utilized by local, regional, and state planning and zoning agencies. Definition Subsurface sewage disposal systems (SSDS) are systems consisting of a house sewer, a septic tank followed by a leaching system, any necessary pumps and siphons, and groundwater control system on which the operation of the leaching system is dependent.

5 This interpretation focuses mainly on the septic tank leaching field and groundwater control system. _____. *. The special requirements identified to overcome soil limitations are a guide to planning and are not to be applied at a specific location without on-site investigation for design and installation. 1. soil Potential Ratings soil Potential Ratings are classes that indicate the relative quality of a soil for a particular use compared to other soils in a given area, in this case the state of Connecticut. The rating criteria were developed by a committee of state and local sanitarians, engineers, and installers. The soils information was provided by the USDA Natural Resources Conservation Service (NRCS). Then the performance and site conditions for a typical system were defined (see Performance Standard). This provided a standard against which various combinations of soil properties for the soils within Connecticut could be compared.

6 The engineering and installation practices used to overcome various soil limitations were listed and their costs estimated. This information was used to identify limitations and costs associated with installing a SSDS on each of the soils in Connecticut. Soils with no or minor limitations for the installation of a SSDS were rated the highest. Conversely, soils requiring extensive site modification and design were rated the lowest. The ease of system installation, and hence cost, formed the basis of the rating scheme. Use Constraints In obtaining this data from NRCS, it is understood that you and/or your organization have the right to use them for any internal purpose. This data is not designed for use as a primary regulatory tool in permitting or citing decisions, but may be used as a reference source. This data is not suitable for site-specific studies or litigation. Inappropriate applications would include a regulatory or policy decision requiring on- site verification or prejudicial judgment based on the soil Potential Ratings information alone.

7 Performance Standard The performance standard is composed of two parts. First, it identifies the capabilities of a typical SSDS. A typical system is assumed to be for a single family, 4-bedroom home on a 1-acre lot with a private well, or a -acre lot with public water supply. The system has a 1250 gallon septic tank and a 660 to 1000 square foot leaching field. Second, it addresses soil and landscape characteristics. This identifies the soil characteristics that are present in order for a typical system to be constructed. 2. The soil characteristics are: 1. Slope is less than 15 percent. 2. soil percolation rate is 1 to 30 minutes per inch. 3. Depth to seasonal high water table is greater than 36 inches below the soil surface. 4. Depth to bedrock is greater than 60 inches. 5. The soils do not flood. Rating Classes The rating class definitions refer to installing a SSDS that will meet state and local health code regulations. Soils with high Potential have characteristics that meet the performance standard.

8 A typical system can be installed at a cost of x. The cost of x represents the going rate for installing a SSDS. The actual value of x varies depending on many factors independent of soil properties. The cost of installing an leaching field is expressed as a multiple of x and is called the cost factor.** The cost factors of 3x and mean that the estimated cost of a leaching field ranges from 3 to times more than a field installed in a soil with high Potential . These cost factors provide relative estimates of the costs in installing a SSDS. soil Potential Ratings are listed in Tables 2 and 3. The soil Potential Ratings and associated cost factors, assuming a typical system, are defined below. High Potential These soils have the best combination of characteristics or may have limitations that can be easily overcome using standard installation practices. The cost factor is 1x to Medium Potential These soils have significant limitations, such as low percolation rate, that are generally overcome using commonly applied designs.

9 The cost factor ranges from to Low Potential These soils have one or more limitations, such as low percolation rate and depth to seasonal high water table, that require extensive design and site preparation to overcome. The cost factor ranges from to _____. **. Cost factors are only a guide. Actual costs will vary both above and below the ranges given. Actual costs will be influenced by on-site features and other variables independent of soil properties. 3. Very Low Potential These soils have to overcome major soil limitations, such as depth to bedrock, that require extensive design and site preparation. A permit for a SSDS may not be issued unless the naturally occurring soils meet the minimal requirements outlined in the state health code. It is unlikely these soils can be improved sufficiently to meet state health code regulations. The cost factor ranges from to Extremely Low These soils have multiple major limitations, such as Potential flooding and depth to seasonal high water table, which are extremely difficult to overcome.

10 A permit for a SSDS may not be issued unless the naturally occurring soils meet the minimal requirements outlined in the state health code. It is unlikely these soils can be improved sufficiently to meet state health code regulations. Not Rated Areas labeled Not Rated have characteristics that show extreme variability from one location to another. The work needed to overcome adverse soil properties cannot be estimated. Often these areas are urban land complexes or miscellaneous areas. An on site investigation is required to determine soil conditions present at the site. The estimated percent of land in the state of Connecticut that fit into each of the soil Potential Ratings is as follows: High Potential Medium Potential Low Potential Very Low Potential Extremely Low Potential Not Rated Evaluation Criteria The evaluation criteria are soil properties that can significantly affect the cost of installing a SSDS. These soil properties correspond to criteria identified in the Connecticut State Health Code Regulations, as well as factors deemed significant by NRCS who developed these soil Potential Ratings .