LEAD CONTAMINATION IN WATER WELLS 
Anthony Reed areed@lorman.alcorn.edu 

Lead is an element that if found in air, food, some paints, dust, soil, and drinking water. Normally, the level of lead in these sources present no public concern. However, exposure to elevated levels of lead has been associated with a wide range of rises, including delays in normal, mental and physical development and impaired learning abilities in children.

A submersible well pump is a water pump that is submerged into the water that is pumped. These pumps are typically 4 inches in the diameter and specifically designed to fit into the water well pipe or casing.

BRASS

Brass (also called bronze in some products) is an alloy of 60 to 90 percent copper and corresponding 10 to 40 percent zinc. However, small amounts of leads are added to brass to make it more malleable. Lead is also added to copper pipe for the same reasons, however, it is in the range of 0.01 to 0.05 percent and is not considered a problem. Water wells constructed prior to the mid-1980's may contain a lead seal (packer) above the screen, and a Lead plug at the bottom of the screen. These lead fittings are potential sources of the lead contamination in drinking water.

The lead ban, passes by Congress in 1986, required that all plumbing, fixtures, solder, and flux be “lead-free”, or have less than 8 .percent lead. This ban applies to any public water public system, or to any plumbing (residential or non-residential) attached to a public system. 

While the lead ban does not apply to private wells, most submersible pump manufacturers voluntarily follow the 8 percent lead limit. However, the EPA has found that submersible brass pumps can leach excessive amounts of leads into water even though manufacturers follow the 8 percent limit. 

WHY ARE SUBMERSIBLE PUMPS SUSPECT

The problem with lead leaching from submersible pumps has to do with brass or bronze fittings and casings, which are in constant contact with water. Non-submersible pumps are not in constant contact with water, and do not pose a great concern, however, some wells with no submersible pumps have brass foot valves or other fittings that may be in constant contact with water, although no data are available in this regard. Users of public water systems should not be concerned because they receive water in which any lead leach from brass pumps is greatly diluted by high volume of water contained in the system.

WHO IS AFFECTED?

Anyone who obtained water from a submersible brass pump should get the water tested. People who may be a t risk are those who obtain their drinking water from individual household wells; however, not every private household well has a submersible pump. People who get their drinking water from public water system are not likely affected because of dilution effects from high flow rates and high volumes, as well as from treatment at the water plant.

WHAT YOU SHOULD DO

If you suspect that your well has a submersible brass pump with the potential to leach lead into your drinking water, you need to have your water tested. Contact the Extension Office about water Sampling Analysis.