As stated in 310 CMR 15.217 (Title 5) Recirculating Sand Filters (RSFs) are approved for General Use in Nitrogen Sensitive areas with flows less than 2,000 GPD at a loading rate of 550 gal/day/acre.
In Remedial Use Applications the following reductions can be taken:
- 50% reduction in soil absorption system;
- Reduction of up to two feet to estimated high ground water;
- Reduction in naturally occurring pervious material.
