The Commonwealth of Virginia Division of Consolidated Laboratory Services assists in protecting the health of Virginians by providing a full range of Public Health Laboratory services, including identifying and investigating infectious and communicable diseases. DCLS monitors and analyzes both groundwater and surface water for the presence of chemical and microbiological pollutants. The Division also maintains a laboratory licensure and consultation program that assures the quality of analytical testing being performed by the clinical and environmental laboratory communities of Virginia. Chlorine Chlorine is the most widely used drinking water disinfectant in North America. Chlorine is added to drinking water as either a gas or after having been already dissolved in water.
Chlorine is measured in the field using portable analytical instrumentation.
Federal and Virginia regulations require at least 0.2 parts per million of chlorine where water enters the distribution system and at least a detectable amount of chlorine in 95 percent of the samples taken from the water distribution system. When the level of chlorine is above 0.5 parts per million, most people can smell chlorine in the water. Cryptosporidium and Giardia Cryptosporidium and Giardia are microorganisms that may be present in human and animal waste. Some people are more vulnerable to these contaminants in drinking water than the general population. Immuno-compromised individuals such as people undergoing chemotherapy, people who have received organ transplants, people who are HIV postive, people with AIDS, the young, and the elderly can be particularly at risk from these infections.