Well Water in Jefferson County: What to Test and Why

Groundwater in Jefferson County contains manganese, chloride, iron, arsenic, nitrate, and sulfate. Several of these contaminants exceed EPA health standards, making testing and treatment an important consideration for well owners.

These contaminants come from the rock and sediment of the coastal lowlands aquifer system. Iron and manganese dissolve naturally from the sediment layers. Chloride enters from saltwater that moves inland from the Gulf of Mexico, mixing with fresh groundwater. Nitrate and arsenic come from both natural rock layers and human activities like agriculture and septic systems.

Groundwater in this county is very hard, driven by elevated calcium and magnesium from the rock layers below. Sodium is notably high as well, a result of saltwater intrusion from the coastal location. These mineral characteristics show up across many wells throughout Jefferson County.

Wells in Jefferson County commonly have arsenic, chloride, iron, manganese, and nitrate at levels that exceed EPA health standards. Arsenic exposure over long periods can increase the risk of cancer and damage organs like the kidney and liver. Nitrate is a concern for infants under six months old and can interfere with how their blood carries oxygen. Manganese at elevated levels can affect brain and nervous system development, especially in young children. Iron and manganese themselves are not toxic at the levels found here, but their presence signals that groundwater is moving through the aquifer in ways that can carry other harmful contaminants.

Wells in this county are very hard, meaning they contain high amounts of minerals that affect daily life. You may see reddish or brown staining on laundry, bathroom fixtures, and dishes from iron and manganese. The water might taste slightly metallic or have an unpleasant odor. Very hard water also reduces how well soap and detergent work, and it can shorten the lifespan of water heaters, dishwashers, and other appliances because minerals build up inside them over time.

We recommend testing your well with a comprehensive metals and minerals panel, since several contaminants exceed health standards in county wells. Your well could have higher or lower levels than what is common in the county, and testing is the only way to know what is actually in your water so you can treat it properly. A comprehensive panel typically costs two hundred to four hundred dollars. Ion exchange systems and reverse osmosis filters can address hardness and remove metals, depending on what your test shows.