Arsenic contamination in groundwater is largely the result of minerals dissolving from weathered rocks and soils which seep into the groundwater aquifers. Arsenic contaminants in drinking water have been linked to several types of cancer, including cancer of the lungs, bladder, kidneys, liver, and sometimes skin. To help prevent over exposure to arsenic, the US Environmental Protection Agency (EPA) has lowered the maximum level of arsenic permitted in drinking water from 50 parts per billion (ppb) to 10 ppb. As of January of 2006, all existing Group A Community and Group A-NTNC sources will be required to comply with the new lower limit.

In Washington State, Snohomish, San Juan and Whatcom Counties have already adopted the new 10 ppb rule for new single family and two-party wells. Other counties will likely soon follow.

Each well has unique raw water characteristics that are like fingerprints in that no two sources of well water are alike. To ensure the successful removal of arsenic, each system should be designed with long term results in mind, to work best with the unique raw water characteristics of the individual well. Garrison Engineering does not represent any particular brand of equipment or sell any products, and therefore is not constrained to one brand of equipment.

Since July of 2002, Garrison Engineering has designed over 400 arsenic treatment systems for public and private water systems. Most of Garrison Engineering's designs have relied on adsorptive iron based media or ferric chloride injection followed by filtration to remove arsenic. Due to co-contaminates in the raw water, we have also designed arsenic removal systems using a variety of other treatment techniques including oxidation/filtration, anion exchange, and reverse osmosis (RO) technologies. The type of treatment is always dependent upon the individual raw water characteristics. Every arsenic removal system designed and installed by Garrison Engineering has met EPA's 10 ppb limit.

Garrison Engineering's water treatment ability also extends into the treatment of iron, manganese, water hardness, tannins, hydrogen sulfide gas (rotten egg odor), surface water, methane gas, lead, fluoride, barium, nitrates, pH adjustment and many others.

To find out more about arsenic removal from drinking water, or if you have other questions about public or private water systems, call Carl Garrison, PE to discuss your next project.