MM-5 (3/15/05 version)
Watershed Restoration And Protection Strategies: Contaminant Infiltration To Ground Water

Chemical or pathogen infiltration to ground water is shown as item D in Figure 1, and includes consideration of risk to ground water quality. For example, if silage juices are draining into a waterway, the use of a drainage well to dispose of the wastes is not an appropriate, because it shifts the contaminants from surface water to ground water. In this situation, a more appropriate management practice might be a constructed wetland or other approach that has a treatment element, instead of just disposal.

Therefore, management practices to address ground water infiltration, may be necessary if:

• a local ground water source is susceptible to contamination based on a DRASTIC score greater than 140; and/or
• a local ground water source is used for drinking water, either within a delineated drinking water source protection area (JPG 174kb) or near a private water supply well; and/or
• NPS is occurring overlying a sensitive aquifer (JPG 574kb); and/or
• the potential for surface and ground water interactions is high.

A considerable amount of jargon exists to describe the mechanisms to address nonpoint sources. Terms include best management practices (BMPs), management practices, management practice systems, management measures, and resource management systems (RMSs).

Management practices systems that focus on ground water integrity are designed to:

• Reduce transport of chemicals to the aquifer via technology based management practices, regulatory controls, or prevention strategies.
• Reduce transport of pathogens to the aquifer via technology based management practices, regulatory controls, or prevention strategies.
• Protect the aquifer from future sources of contamination.