Performance of a Textile Filter, Polishing Sand Filter and Shallow Trench System for the Treatment of Domestic Wastewater at the Northeast Regional Correction Center

Abstract

An estimated half million households in Minnesota are not connected to public sewer systems. Along with the growing use and expansion of lakeshore cabins and resorts, many have the potential to degrade surface and groundwater resources as they depend primarily on individual sewage treatment systems (ISTSs) for the treatment and dispersal of domestic wastewater. Unfortunately, many are in noncompliance with state standards or are hydraulically failing to the surface. Effective treatment options are needed for the thousands of locations with restrictive soil and site conditions. Many of these sites occur along lakes and streams, creating a potential health hazard to swimmers and others using surface water for drinking water and recreation, leading to increased algal blooms, aesthetic nuisances and degraded fish habitat. Packed bed textile filters, coupled with a site-specific soil dispersal system, were one of several options evaluated in Minnesota. Other systems tested in northeast Minnesota have included sand filters (single pass and recirculating), peat filters (in-ground and module), subsurface flow constructed wetlands, aerobic treatment unit, standard trenches, gravel filter and drip distribution (McCarthy et al., 1997, 1998, 1999, 2001; Anderson and Gustafson, 1998; Henneck et al., 1999, 2001; Axler et al., 1999, 2000; Monson Geerts et al., 2000, 2001; Pundsack et al., 2001; Christopherson et al., 2001). This paper provides an overview of the operation and performance of a recirculating packed bed textile filter, polishing sand filter and shallow gravelless trenches at the northern Minnesota research facility.