The City of Centralia Public Works Department released the city’s 2022 water quality report in May.
Of the more than 100 contaminants the city tested for, the water did not exceed any state or federal contamination limits, according to the report.
Centralia’s water is classified as groundwater, meaning it is sourced from drilled wells. Underground aquifers being tapped by the wells are susceptible to contamination from above-ground activities.
Lead, arsenic, copper, radium 228, nitrate, total trihalomethanes and haloacetic acids were among the contaminants tested for.
There are both natural and human causes for many of these contaminants, including erosion of natural deposits into local aquifers, corrosion of plumbing systems, runoff from fertilizer use or being byproducts of the drinking water chlorination process.
Other contaminants include microbial matter from broken sewer lines, leaking septic systems, livestock operations and wildlife as well as inorganic matter from industrial and domestic wastewater discharges, oil and gas production, mining, farming or stormwater runoff containing salts and metals.
The public works department uses three treatment methods for Centralia’s water: air stripping, chlorination and fluoridation.
Air stripping involves large volumes of air being forced through the water to remove dissolved gas and volatile substances. It is also the main method used to reduce copper and lead levels in the water by increasing the water’s pH level from 6.7 to 7.7, the report stated.
Despite these results, the report still shared this warning from the Environmental Protection Agency (EPA) concerning lead and copper contamination:
“Infants and children who drink water containing lead in excess of the action level could experience delays in their physical or mental development. Children could show slight deficits in attention span and learning abilities. Adults who drink this water over many years could develop kidney problems or high blood pressure. Some people who drink water containing copper in excess of the action level over a relatively short amount of time could experience gastrointestinal distress. Some people who drink water containing copper in excess of the action level over many years could suffer liver or kidney damage. People with Wilson’s Disease should consult their personal doctor.”
Chlorination is used to disinfect the water supply and sits at between 0.2 and 1.2 parts per million (ppm) in samples tested, according to the report. The EPA established the maximum residual disinfectant level for chlorine in water at 4 ppm and the maximum residual disinfectant level goal at 4 ppm.
Fluorination is used to aid in tooth decay prevention. Fluoride levels are maintained at levels between 0.5 and 0.9 ppm, according to the report. The EPA established the maximum contaminant level goal for fluoride at 4 ppm.
Public Works personnel are also trying to help conserve water. They fixed a total of 109 leaks throughout both main and service lines in 2022.
To help prevent contamination, the report asked residents to properly dispose of used oil, gas, pesticides and other hazardous chemicals instead of dumping them on the ground or down sinks and toilets.
For more information on hazardous material disposal, call the Lewis County Hazo Hut at 360-740-1221 or visit https://lewiscountywa.gov/departments/solid-waste/hazo-hut/.
For more information regarding the city’s 2022 water quality report, call Centralia Public Works at 360-330-7516.
To view the 2022 water quality report and reports from previous years, visit https://www.cityofcentralia.com/Archive.aspx?AMID=42.
