New State Initiatives 



effluent application sites; and radioactive waste-related sites must comply 

 with applicable controls, without exception. 



♦♦Establish design, construction, and performance standards to accomplish the dual goals 

 of control of runoff and maintenance of groundwater infiltration levels, where recharge of 

 stormwater would not contribute to groundwater contamination. 



***Prepare clear guidance regarding specific runoff control and infiltration 

 enhancement practices to be required for different types and sizes of 

 construction projects. In that respect, set threshold criteria based on aggregate area of 

 land involved; extent of impervious surface coverage; extent of lawn coverage; and other 

 factors relevant to runoff (including slope, existing drainage characteristics, etc.) Specify 

 means by which other development projects are to be included in the stormwater 

 management program if they: contribute to stormwater nmoff resulting in exceedance of the 

 safe capacity of existing drainage facilities or flood storage capacity; cause channel erosion, 

 scouring, or particulate transport; or endanger downstream property. 



**Require submission of integrated stormwater management and sediment 

 and erosion control plans for all applicable developments. 



Design and Performance Specifications 



**Specify an order of preference for practices which will be adhered to in review, but 

 provide the designer as much flexibility as possible in meeting applicable standards. 



♦♦Develop runoff calculations (based upon SCS curve numbers for various hydrologic soil 

 groups) to use in calculating runoff volume so as to provide control of post development 

 volumes resulting from a one year design storm ranging in duration from one half hour to 

 24 hoiu^ duration. 



♦*Use Stormwater Management and Erosion Control Committee guidance 

 (hereafter Committee Stormwater Guidance) regarding stormwater 

 management to make determinations as to the appropriate use of inflltration 

 basins. (Careful evaluation of potential groundwater impacts is required in decision- 

 making regarding this issue.) Establish standards and specifications for all practices which 

 ensure compatibility with safety concerns and other resource protection objectives. For 

 example, with respect to safety and groundwater protection considerations of concern in 

 siting of infiltration basins, set standards and specifications to ensure that; 



a) infiltration systems are not used to receive large voliunes of contaminated rtinoff 



b) infiltration systems do not undermine the structural integrity of neighboring 

 structures 



c) infiltration systems receiving small to moderate amounts of contaminated runoff 

 have incorporated treatment devices or are located a sufficient distance ftx)m public 

 or private water supply wells to provide adequate natural treatment 



♦♦Require that in watersheds not currendy used for water supply, sedimentation basins and 

 infiltration devices be installed (as indicated to be appropriate by Committee Stormwater 



167 



