* Updated July 12, 2019
The City of Denmark Public Water System is a small rural water system that serves a population of approximately 5,600 customers (residents, students at two local colleges, and commercial and industrial properties). The wells withdraw groundwater from an aquifer approximately 300 feet below ground. The water is treated with chlorine to disinfect for bacteria prior to distribution.
The City's drinking water is safe for drinking, bathing, and cooking based on it being in compliance with the Primary Drinking Water Standards under the Environmental Protection Agency's (EPA) Safe Drinking Water Act and State of South Carolina Drinking Water Regulations.
The South Carolina Department of Health and Environmental Control (DHEC) has delegated authority from the EPA to administer and enforce drinking water quality standards and regulations set by EPA. These regulations authorize DHEC to oversee compliance of the City’s water system. DHEC conducts sanitary surveys (annual inspections) and performs compliance sampling of the water system. DHEC also works with the City to provide compliance assistance through technical consultation, education, and source water protection evaluation.
"EPA is working collaboratively with SCDHEC as they continue to act to ensure the safety of the drinking water in the Town of Denmark, including collecting and analyzing samples from the drinking water system.
The SCDHEC requires that products used for treating drinking water be certified by NSF International, an independent, third-party certification organization. NSF International standards are used by many states as a quality assurance practice. The purpose of the NSF/ANSI-60 standard is for the control of potential adverse human health effects from products added to water for its treatment. HaloSan was certified by NSF International for use in drinking water." - Environmental Protection Agency
The City’s drinking water currently meets the requirements of the EPA’s Safe Drinking Water Act and the State Primary Drinking Water Regulations. See the latest Public Water System Supervision (PWSS) annual review.
In addition to required compliance sampling, DHEC has, over the years, collected samples to investigate concerns expressed to the Department. There were also two special studies conducted in April 2018. Information and data from the events are shared on these pages as well as in Fact Sheets that appear as links.
Iron & Manganese
EPA has established National Secondary Drinking Water Regulations that set non-mandatory water quality standards for 15 contaminants, including iron and manganese. Contaminants can be naturally-occurring or man-made chemicals found in the environment. If these contaminants are present in water at levels greater than these standards, they may cause the water to appear cloudy or rust-colored, or to taste or smell bad even though the water is actually safe to drink.
While the discoloration caused by iron and manganese is not a health concern, it is not desirable. Iron and manganese are not routinely monitored in drinking water systems. Iron and manganese may come from source water and/or pipes in a system or building.
EPA has established guidelines to assist public water systems in managing their drinking water for taste, color, and odor. DHEC has made specific recommendations to the City that have improved the levels of iron and manganese found in the water (see fact sheet for Special Study data). Click here for Iron & Manganese data from 2007 - Present.
Lead & Copper
EPA developed the Lead and Copper Rule (LCR) under the Safe Drinking Water Act to control lead and copper in drinking water.
Lead and copper can be found in older distribution lines and in plumbing and fixtures inside of homes and businesses. For this reason the EPA LCR requires that sampling be done inside homes and businesses. There are very specific procedures for collecting what should be worse-case samples, meaning they have the higher percentage chance of finding lead.
In the last ten years, the City conducted official LCR monitoring eight times. The sampling results demonstrated compliance with the EPA Action Levels for lead and copper as required under the LCR.
For further information on how to reduce the potential for exposure to lead or copper in drinking water, visit: Sources of Lead in Drinking Water - (PDF)
HaloSan & Disinfection Byproducts
HaloSan was used to control iron bacteria in the Cox Mill Well 300 feet below ground. A small, set amount was dispensed by an automated system designed and calibrated by the supplier. The active ingredient in HaloSan is bromochlorodimethylhydantoin.
HaloSan was approved by the American National Standards Institute/National Sanitation Foundation (ANSI/NSF) and deemed safe for its intended use (Official NSF Statement - PDF). DHEC is required by State regulation to rely upon ANSI/NSF Standard 60-Health Effects for approval of chemicals added to drinking water.
In July 2018, coming out of the Partnership Special Study, a question was asked about whether HaloSan (used to control iron bacteria in the Cox Mill Well) must be registered under the EPA Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). HaloSan was classified as a pesticide because it was used to kill bacteria. It is the responsibility of the supplier to register their product(s) with FIFRA. In South Carolina, the EPA delegates regulatory authority for implementation of FIFRA to Clemson University’s Department of Pesticide Regulation (CU DPR). CU DPR determined that HaloSan required FIFRA registration and issued a stop-sale and use order to the supplier and a stop-use order to the City. DHEC then contacted the City and presented the options of finding substitute chemical that was both FIFRA registered and ANSI/NSF Standard 60 approved or removing the Cox Mill Well from service. The City chose to take the Cox Mill Well offline.
HaloSan was approved for its intended use as a disinfectant by the NSF. That approval as a drinking water additive is required by State Drinking Water Regulations.
Chlorine is commonly used as a disinfectant to kill disease-causing bacteria in drinking water. Disinfectants like chlorine and bromine (halogens) can create disinfection byproducts (DBPs) in water when there is excess organic matter. DBPs are chemical compounds that may occur when a halogen-based disinfectant reacts with organic matter (e.g. tree leaves, insects). Regulated DBPs include Total Trihalomethanes (TTHMs) and Haloacetic Acids (HAA5s).
As long as the use of all disinfectants (chlorine and HaloSan) does not cause the amount of DBPs to exceed the concentrations listed in the EPA’s Disinfection Byproducts Rule, there is no unacceptable risk to human health. In the last ten years, the City has not exceeded the EPA’s Disinfection Byproducts Rule.
The City of Denmark's drinking water currently meets the requirements of the Federal Safe Drinking Water Act and the State Primary Drinking Water Regulations.
The City's water supply has been and continues to be disinfected with chlorine. Chlorine is a chemical that is added to drinking water to disinfect it. Disinfection is an important step in ensuring that water is safe to drink. The presence of chlorine residual in drinking water is an important indicator of safe and protected drinking water.
- NSF Webpage
- Clemson Department of Pesticide Regulation
- EPA FIFRA
- State Drinking Water Regulations
- EPA Safe Drinking Water Act
- EPA MCL Table
Any citizen who would like to share concerns about water quality and/or request sampling in his/her home is asked to contact our DHEC Regional Office in Orangeburg.
DHEC Orangeburg Regional Office
1550 Carolina Ave.
Orangeburg, SC 29116
This webpage will continue to be updated with new information as it becomes available.