What are RI Towns Doing?
Block Island
South Kingstown

The BIGHP Project

RIWIS (Rhode Island Wastewater Information System)

Onsite Systems Basics
Onsite treatment systems
Property owner's guide

Wastewater Manager's Toolkit
Creating a management plan
Drafting an ordinance
Developing treatment standards
Funding and staffing a program
Getting the message out
Tracking inspections
Achieving results

Onsite System Research and Assessment
Demonstration systems
Soil suitability
Using GIS for evaluation
Water quality monitoring

Training and technical support

This website is under construction.

Please check back soon for more complete information!

Treatment Technology: Recirculating foam filter
Foam filters use 2- to 3-inch cubes of open-cell polyurethane foam material that is randomly arranged in prefabricated modular units, typically in cylindrical wire baskets. The foam filters are usually configured with a single tank, using programmable timer and controls. The effluent is distributed evenly over the foam media by helical-type spray nozzles.
A treatment train containing a recirculating foam filter

Wastewater flows out of the home through a building sewer (A) and into a two-compartment tank (B). Effluent is pressure dosed using a time dosed pump located in the second compartment of the tank. Effluent is distributed over the top of the foam media (C), flows down through the foam media and to the base of the filter. Filtrate collects in a sump area at the filter base, where a second pump is located. This pump pressure doses foam filter effluent, a portion of which flows back to the inlet end of the septic tank. In this example the remaining effluent is pressure dosed to a bottomless sand filter (D) where additional treatment and dispersal occurs.
Treatment performance observed for recirculating foam filters in RI
% TN Reduction
Fecal Coliform
Coming Soon!
For more information on recirculating foam filters:
Web Links:This technology is a proprietary device under the trade name Waterloo Biofilter® manufactured by Waterloo Biofilter Systems Inc. For more information on this system technology, see the vendor website at www.waterloo-biofilter.com.
Copyright 2006 URI Water Quality Program