Cleaning up Groundwater under Direct Influence of Surface Water

Although you may not have ever heard of it, the bowel infection giardiasis afflicts more than 2.5 million people in the United States every year. In undeveloped countries, it can affect as much as 20-30% of the population. The reason it’s so prevalent is that it is caused by a protozoan parasite that gets into water systems all over the world. If these protozoans get into your system, you will start feeling very sick. Therefore, it’s important for municipal water systems to maintain strict standards on ground water under the direct influence of surface water in order to eradicate protozoan populations and maintain public health.

Groundwater is said to be under the influence of surface water if there is a direct link between the two. Groundwater includes private wells and underground springs. Surface water is more subject to contaminants which, if there’s a direct link, can be passed through to the groundwater. Water treatment facilities need to be able to identify the source of the parasites in order to eliminate the problem at the source. Since surface water can feed into numerous underground water reserves, the problem of giardiasis can spread quickly unless the source is found and treated.

As per the Surface Water Treatment Rule established in 1989, the established tolerance for Giardia and other common parasites in drinking water is zero. That is because these parasites present a health risk to the public. This rule also set forth the guidelines for the techniques that need to be used to get rid of the contaminants and established the requirements that drinking water which is entering the distribution system must have continuous disinfection and a level of disinfectant in the system that is detectable.

The Federal government requires that all groundwater under direct influence of surface water undergo a three-step process in order to determine the amount of contamination. These steps are:
1. Testing in order to establish the quality of the water and the types of contaminants that it contains.
2. Monitoring on a daily basis for the long-term.
3. Follow-up checks for water quality.

The Department of Health requires that water systems using contaminated groundwater under direct influence must take additional steps it has outlined in order to correct the problems. The water treatment system may be required to filter or disinfect all of its water and that the facility be run by licensed workers. The guidelines seem to be working in most areas, too. Unfortunately, some Giardia and other parasites are still managing to get through the systems that are in place. This is not acceptable, and water management will continue to be monitored until the zero tolerance established by the rule is a reality.