As stated in 310 CMR 15.217 (Title V) 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/acre.
In Remedial Use Applications the following reductions can be taken:
- 50% reduction is soil absorption system;
- Reduction to ground water;
- Reduction in naturally occurring material.