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SOUTH DAKOTA
South Dakota's nonpoint source program will take a balanced approach using
four major elements-- implementation, demonstration, information and education,
and research--to achieve better water quality. The programs's ultimate goal is
to implement best management practices to contain nonpoint sources of water
pollution. To achieve this goal, the East Dakota Water Development District
worked with local city and county groups to develop and pass local ordinances
to ensure groundwater and wellhead protection.
Protecting the Big Sioux Aquifer
Aquifers are significantly tied to surface waters, making them sensitive
and vulnerable to both point and nonpoint source contamination. This is why the
East Dakota Water Development District (EDWDD), a regional organization
concerned with water issues, spearheaded a movement to learn more about
aquifers, their relative sensitivity to contamination, and measures needed to
protect them. The Big Sioux Aquifer and other smaller surface aquifers lie
under approximately 1,000 square miles of eastern South Dakota. They supply
drinking water to about one-third of the state's population.
Although no widespread pollution problem existed, studies had uncovered
isolated cases of contamination. Nitrate has contaminated numerous public water
supplies, and some 80 cases of methemoglobinemia (blue baby disease) have been
documented, with approximately $2.6 million spent to replace or drill new wells
to avoid high nitrate levels. In one study, 30 percent of the private wells
tested had bacterial contamination and/or nitrate levels above safe drinking
water standards. Clearly, a grassroots effort was needed to protect the
aquifers.
With $204,996 of section 319 funds and $136,000 in in-kind contributions
from citizens and other organizations, the EDWDD began the Big Sioux Aquifer
Protection Project. Its goal was to protect the Big Sioux Aquifer and other
sensitive shallow aquifers from contamination. Its method was to develop and
pass local zoning ordinances to ensure protection.
Before such a project could be effective, an intensive information and
education campaign was needed to inform local organizations--primarily counties
and cities--and citizens about the potential problems threatening their water
supplies. Through meetings with various community and other public groups, the
EDWDD urged individuals and organizations to take quick, decisive action to
protect their most important natural resource.
To begin the project, EDWDD identified shallow aquifers vulnerable to
contamination and located 30 public water supply wells within the project area.
It also gathered as much information as possible about the public water supply
wells to help delineate a wellhead protection area (WHPA) for each one. The
most useful information included public supply, well depth, pumpage rate,
hydraulic gradient, and transmissivity.
EDWDD developed a model groundwater protection ordinance that allowed city
or county zoning authorities to limit the kinds of activities within the WHPA
and used it to promote the concept of groundwater protection through
regulation. Over a period of two years, localities modified the model ordinance
to develop ordinances to - accommodate local conditions. As of August 1993, two
cities and nine counties had adopted ordinances, with several more in the
process.
Local ordinances protect groundwater by limiting or prohibiting specific
activities within the WHPA such as:
- New feedlots and/or manure storage facilities,
- Solid waste storage facilities--dumps and landfills,
- Deicing chemical and road salt storage,
- Car washes--oil, degreasers, and other associated contaminants,
- Open burning,
- Wastewater facilities,
- Waste oil spreading on the land,
- Storage of various hazardous or toxic chemicals such as PCBs,
- Activities associated with internal combustion engines such as auto
service/repair stations and junk yards,
- Class V wells, and
- Fall application of fertilizers containing nitrogen.
Since ordinances are not designed to deal with accidents such as hazardous
or toxic material spills, the City of Sioux Falls is developing a water supply
contingency plan. Other communities have expressed interest in developing
similar contingency plans.
To identify and address existing sources of contaminants, EDWDD undertook
five additional activities under the project. They were:
- A Class V Injection Well Control Demonstration Project that identified 15
Class V wells (activities that dispose of waste, other than household, through
a septic tank) and prepared measures to eventually close those wells;
- An informational video that discussed the Class V injection well
issue;
- A Shallow Abandoned Well Sealing Demonstration Project to seal unused wells
that could contaminate the underlying aquifer;
- A USDA Big Sioux Aquifer Water Quality Demonstration Project to demonstrate
the impact of selected BMPs on water quality of groundwater; and
- A study of feedlot contaminants of shallow aquifers to track the aerial
extent and magnitude of groundwater contamination from six feedlots.
Other related area activities included installing 48 monitoring wells within
nine WHPAs to provide an early detection system and using the Farm*A*Syst
Program to inform landowners in rural areas about threats to their domestic
wells.
This protection project has clearly succeeded in limiting or preventing
activities that could contaminate groundwater. The variety of activities
contained in the project evoked much interest, and the project sponsor was
invited to speak at a number of national and regional conferences. The concept
of using ordinances to protect aquifers in urban and/or rural areas has been
effectively used by other states throughout the country to protect water
quality.
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