Overview:

Homes near Rock Bridge Memorial State Park in central Missouri are located on a unique geologic feature largely invisible from the surface: karst terrain.  Karst terrain is characterized by the presence of sinkholes, springs, caves, and an underground drainage system.  the area surrounding and including the state park possesses all of these characteristics.  Devil's Icebox Cave is the sixth longest in the state and runs through the park.  The Pierpont sinkhole plain and Bonne Femme Creek form the recharge area for the cave.

Such areas provide habitat for many interesting and often rare creatures.  Devil's Icebox Cave, for example, is home to two endangered species: the gray bat and the Indiana bat.  Another cave resident is a candidate for the endangered species list: the pink planarian, a flatworm found nowhere else in the world.

In addition to natural habitat, karst terrain creates special challenges for wastewater treatment and disposal.  In the Rock Bridge area, soils are seasonally wet with high clay content, which reduces their permeability.  Water often flows laterally (instead of percolating downward), then drains into sinkholes, subterranean streams, and ultimately other waterways.

Once a primarily agricultural area, Rock Bridge has seen much of its farmland converted to residential developments as the city of Columbia encroaches from the north.  All of these homes use onsite wastewater systems.  Most systems were installed prior to the Boone County Onsite Code implemented in 1992, which sets minimum standards for onsite systems.  Wastewater from the inadequately functioning or failing systems was directly discharged to sinkholes or seeped through the ground.   Water quality sampling detected high levels of bacterial contamination in nearby creeks, and elevated nitrate levels in private wells.

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An innovative technology and management district demonstration in an impaired watershed in southern Pennsylvania.
Clement Solomon, David Pask and Len Lichvar

Overview:

Centerville, Pennsylvania, is a small village in the southern Allegheny Mountains, just north of the Maryland/Pennsylvania border.  Along the eastern edge of the town flows Evitts Creek, whose dammed waters form Koon and Gordon Lakes on their way to the Potomac River.  These reservoirs are the sole source of drinking water for more than 60,000 residents of Pennsylvania, Maryland, and West Virginia.

Recently, algal blooms, odors, and an unpleasant taste have drawn attention to the declining water quality of Evitts Creek.  Excessive nutrient inputs from non-point sources within the watershed are a suspected pollutant source.   This watershed has a "high quality" designation from the Pennsylvania Department of Environmental Protection (PA DEP), making its restoration a priority.   This designation requires that no-discharge and advanced treatment options be considered for onsite systems.

Centerville is in Cumberland Valley Township, and the Cumberland Valley Sewer and Water Authority is responsible for its wastewater systems.   All 64 homes and a few businesses were served by conventional systems, with 70 percent malfunctioning.  Eighteen were connected to a pipe that conducted effluent straight into a nearby stream, without any treatment.  Other homes also discharged untreated wastewater directly to ditches or streams.  As part of an effort to reduce pollution in the watershed, Centerville's wastewater treatment methods were assessed for possible improvement.  The project was originally intended to demonstrate one alternative cluster system, but evolved into a comprehensive wastewater treatment and management plan for the entire town.

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Demonstration of innovative onsite wastewater systems in the Green Hill Pond watershed of Rhode Island.
Clement Solomon, George Loomis and David Dow

Overview:

Rhode Island's coastal plain is dotted with bodies of water known as salt, or coastal, ponds.  In a small state where undeveloped acreage is scarce, the pressure to develop aesthetically appealing land near the ocean is especially intense.  Therefore, nearly all of the unprotected land surrounding the coastal ponds has been developed for residential or recreational purposes.

In addition to being popular sites for human use, the salt ponds also harbor a unique ecosystem.  Sunlight penetrating the shallow water supports beds of eelgrass (Zostera marina).  Eelgrass beds form an important nursery area for fish and shellfish and are a source of food for waterfowl.  Coastal ponds also serve as habitat for migrating and breeding birds.

Development around the ponds has caused an increase in non-point source pollution.  A prime example of this phenomenon is Green Hill Pond, located along the southern Rhode Island coast between Charlestown and South Kingstown.   It has experienced a significant decline in water quality in recent years and has been closed to shellfishing since 1994 due to elevated bacteria levels.  The pond's only connection to the ocean is through a neighboring pond, so contaminants that run or seep into the pond tend to accumulate, rather than being flushed away.

The density of residential units is as high as eight units per acre.  All of the approximately 2,200 homes in its six-square-mile watershed use onsite wastewater systems.  Many of these systems predate current regulatory codes, and often use cesspools.  Malfunctioning residential wastewater systems are major contributors of bacteria and excess nitrogen.  These pollutants pose a threat to public health and the environment in the form of bacterial and nutrient contamination.

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Overview:

Site conditions such as clay, shallow bedrock, or steep slopes limit the effectiveness of conventional onsite systems in Vermont.  These factors, when combined with improper design, installation, and maintenance, have led to a high failure rate for onsite wastewater systems in the state.  Demonstration of effective, alternative wastewater systems can help homeowners in Vermont find cost-effective and environmentally sound solutions to their wastewater problems.   This project, under the leadership of the State of Vermont Department of Housing and Community Affairs, was initiated to demonstrate and promote the use of alternative wastewater systems in state and local codes, and provide management of onsite systems to protect public and environmental health.  Two counties and three communities participated in this project.

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Overview:

Burnett is a small, unincorporated community in Pierce County, Washington, located in a rural area southeast of Tacoma.  Burnett was originally built during the coal boom era, then reconstructed at a later time over the mines, shafts, tunnels, cave-ins and old sewer and water lines.  These features all served as conduits for partially treated or untreated wastewater to flow into nearby South Prairie Creek, an important salmon spawning habitat.

All of the approximately 50 homes are served by onsite wastewater systems.  In 1998, a wastewater risk assessment survey conducted by the Washington Onsite Sewage Association (WOSSA) and funded by the Pierce County Department of Community Services indicated that 15 of the 50 onsite wastewater systems were failing or malfunctioning.  The systems were ranked by risk to public health and threat of contaminating South Prairie Creek.

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Monongalia Management and Maintenance Partnership Project (3MP), Monongalia County, West Virginia.
Clement Solomon, Art Adams and Kirk Powroznik

Overview:

Monongalia County is located in north-central West Virginia.   The Mason-Dixon Line forms the county's northern boundary and part of the West Virginia/Pennsylvania border.  A prominent geographic feature in the county is the Monongahela River, which winds through the county on its way to Pittsburgh, where it joins the Allegheny River to form the Ohio River.

In recent years, the county has experienced unplanned growth and exceeded infrastructure improvements.  Unplanned development has caused the county to outgrow its public sewer system and look to onsite wastewater systems to serve its rural areas and parts of the urban communities.  Residents in the county have not been able to connect to public sewers due to the mountainous topography and somewhat isolated communities.  Subdivisions and new homes are being built outside the towns at a rapid rate.  The use of onsite systems has become a long-term, viable alternative to centralized sewers.

Topography and site conditions vary across the county; soils are often rated as "severe" for onsite systems.  Public health and environmental risks result from effluent surfacing and pooling on drainfield areas, or from direct discharges to streams, lakes, or rivers.  Inappropriate system selection, design, and poor sitting and installation techniques have often caused system failure.

Some systems in former coal-mining communities either partially treated or directly discharged wastewater into nearby bodies of water, and were not approved systems.  Although new alternative systems were being installed in the county, long-term maintenance of both old and new systems was frequently ignored.   Residents often lacked the desire and/or financial resources to upgrade inadequate or malfunctioning systems.  An innovative way to manage and facilitate proper onsite wastewater treatment was needed.