Performance of an Aerobic Treatment Unit and Drip Dispersal System for the Treatment of Domestic Wastewater at the Northeast Regional Correction Center

Abstract

An estimated half million homes in Minnesota are not connected to public sewer systems. Along with the growing use of lakeshore cabins and the conversion of cabins into year-round homes, 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 oflocations 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. The suspended-growth wastewater treatment process is commonly used by municipal wastewater treatment facilities. This biological treatment process is also available at smaller scales for both individual and multiple home use, and are commonly referred to as aerobic treatment units or ATU's. Since the mid-1990's, systems using both the suspended-growth and fixed-film treatment processes were evaluated for single-family home use in northern Minnesota (McCarthy et al., 1997, 1998, 1999; 2001; Henneck et al., 1999, 2001; Axler et al., 1999, 2000; Monson Geerts et al., 2000, 2001; Pundsack et al., 2001). This paper provides an overview of the operation and performance of one brand of aerobic treatment unit and a drip dispersal system tested at the northern Minnesota research facility.