Sediment in Drinking WaterSediment is one of the most common drinking water contaminants. Sediment normally occurs due to organic or inorganic matter being carried by wind or runoff into open water sources. Sediment in water sources very often originates from non-point sources due to runoff from construction sites, agriculture, logging, flooding, erosion of river banks, and debris washed into waterways from city streets. Sediment can be very problematic in water systems, as it not only smothers aquatic organisms, but it can also clog plumbing and piping, and can be abrasive, causing damage to plumbing fittings and valves. It can also affect clarity and turbidity, making drinking water unappealing. Depending on the particles held in suspension, the sediment may also give the water a foul taste or odor, making it even more objectionable and unpalatable.
Different Types of Sediment Found in Drinking WaterDrinking water contaminants in the form of sediment can result from sand and dirt, rust, or from suspended plant and animal matter. These contaminants are sometimes introduced some distance away (non-point sources), but sediment may also be released into a water supply locally.
Brown or orange colored sediment particles in water are usually rust particles that stem from corroded water pipes and plumbing. The particles break free from the piping in flakes, and thus usually occur in irregular shapes and sizes. Rust forms as a result of a chemical reaction between iron and oxygen to form iron-oxide (rust). Dissolved minerals, such as iron and manganese, may also precipitate, leaving traces of sediment. Iron does not pose a health risk, but it can be annoying if the sediment blocks aerators on taps, shower roses and filters, or if the sediment accumulates and blocks pipes, restricting flow.
Black sediment can indicate a high level of manganese in the water, or it could stem from a more local source, such as corroded steel piping. Very often plumbing washers and pipes are made of black rubber, which tends to break down over time as a result of the corrosive action of chlorine and chloramine disinfectants in the water. As the rubber is degraded, small black specks are released into the water as the rubber disintegrates. Fine black sediment that looks like coffee grinds may be activated carbon granules that stem from a carbon filter, which may indicate that the filter cartridge needs to be replaced.
White or tan sediment in drinking water is usually a result of calcium carbonate and magnesium carbonate, commonly known as pipe scale. Both these minerals are commonly found in drinking water and their quantities in water determine the hardness or softness of water, with higher concentrations causing the water to be harder. While pipe scale does not pose a health risk, it can accumulate and build up in pipes, and like rust, it may eventually break away and clog taps and filters, and cause water flow problems.
Water Purification Filters to Remove SedimentFiber filters offer an effective water purification method to remove sediment from drinking water. Water is forced through the filter, which consists of filtering mesh media ranging in pore size from fine to coarse, with finer micron mesh having a lower rating. The filter traps particles suspended in the water as it flows through the filter. While fiber filters are effective at removing suspended particles and some dissolved organic compounds, if the water still has an unpleasant taste or odor after filtration, a carbon filter may be necessary to remove taste and odor causing drinking water contaminants.
Herman, G.M. & Jennings, G.D. Home Drinking Water Treatment Systems. Water Quality & Waste Management. North Carolina Cooperative Extension Service. HE-419. http://www.bae.ncsu.edu/bae/programs/extension/publicat/wqwm/ebae144_90.htmlMassachusetts Department of Environmental Protection. Color, Taste & Odor: What you should know. Water, Waste and Wetlands. http://www.caes.uga.edu/Publications/pubDetail.cfm?pk_id=8001