ISDS 



The two-tiered definition is based upon the precept that escalating development 

 occurring and anticipated in the state demands that all soils presenting constraints to ISDS 

 development (in the natural state of the soil strata prior to draining, excavation, or other 

 alteration) must be considered as presenting potential risk to future water supply 

 development and/or potential health hazard risk. 



Sensitive areas are considered to include: 



• groundwater recharge zones of municipal water supplies 



• coastal watersheds (Coastal Ponds watersheds and watersheds of poorly flushed 

 embayments are considered Critical Areas) 



• surface water supply watersheds 



• Wood/Pawcatuck River Watershed. 



Sensitive Area soils include: 



• upland till soils characterized by: 



-steep slopes 



-slow permeability 



-seasonal high water table 



-shallow depth to impermeable layer (haidpan) 



-excessively rapid permeabilities 



• glacial outwash soils characterized by: 

 -excessively rapid permeabilities 



• coastal sands characterized by: 



-excessively rapid permeabilities 

 -high water table 

 -flooding potential 



(others as denoted by the USDA Soil Conservation Service) 



Specific soil families include Paxton, Woodbridge, Ridgebury, Whitman, Leicester, 

 Canton-Charlton, Sutton, Hinckley, Agawam, Enfield, Bridgehampton, Menimac, 

 Matuiuck, Gloucester, and Wapping, 



Recommendations to the Department of Environmental Management 



***Develop specific ISDS siting, design and maintenance standards for use 

 in areas where effluent may potentially impact surface water supplies, 

 sensitive water bodies, and/or other critical areas in such a way as to 

 hinder attainment of water quality and use goals. Revise ISDS standards to 

 include full descriptions of standards to be applied in these areas. 



**Revise ISDS regulatory language to state specifically that RIDEM 

 regulations establish minimum standards and that more stringent standards for 

 ISDS siting may be adopted by local governments for protection of critical areas. Describe 



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