Eastern Municipal Water District (EMWD) serves about 142,000 customers in Riverside County, CA. The EMWD service area is one of the largest for any water district in arid southern California. On the drinking water side, EMWD manages two water treatment plants and over 15 reservoirs. With 70% of the district’s water coming from the Metropolitan Water District with chloramine disinfection, EMWD has become reliant on chloramine disinfection to manage long transmission lines and longer detention times.
Bluebonnet Rural Water Corporation (BRWC), a subsidiary of Bluebonnet Electric Cooperative, serves approximately 1,094 water meters in northeast Washington County, TX, but had a water storage problem not unfamiliar to even the largest water utilities in Texas.
“To me, Microclor® is the top of the line on‐site generation system on the market due to low maintenance and it being very user friendly.” Larry English, Water Quality Manager, Daphne Utilities. Read the full project profile to learn more.
Levels of a widely used class of industrial chemicals linked with cancer and other health problems — polyfluoroalkyl and perfluoroalkyl substances (PFASs) — exceed federally recommended safety levels in public drinking-water supplies for 6 million people in the United States, according to a new study led by researchers from the Harvard T.H. Chan School of Public Health and the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS).
When the City of Midlothian, Texas, was ready to expand their water treatment plant to accommodate a growing population, they carefully considered and investigated their water disinfection options.
Originally built to treat 10 million gallons per day (MGD), the Quail Creek Water Treatment Plant in Washington County, Utah, now has an operational capacity of 60 MGD and a design capacity of 80 MGD.
In the fall of 2015, a small village on the border of Vermont in New York State, tested positive for Perfluorinated Compounds (PFCs), specifically Perfluorooctanoic Acid (PFOA), in the municipal drinking water. The influent levels of PFOA in the water were above 600 ng/L, and thus considered harmful to village residents. Realizing that PFOA was on the U.S. EPA Contaminant Candidate List, the Village solicited the services of engineering firm CT Male Associates to investigate treatment options and provide a treatment system.
When the Cobb County-Marietta Water Authority (CCMWA) anticipated the need to upgrade the Hugh A. Wyckoff water treatment plant, they turned to granular activated carbon (GAC) technology after vetting several alternatives. The plant, a wholesaler in a two-plant system, processes up to 72 million gallons per day and serves about 350,000 people. Comprising of Wyckoff and the James E. Quarles treatment plant, CCMWA is the second largest water provider in Georgia.
The City of Salem uses a slow sand filtration water treatment process, which uses naturally occurring biological activity to clean drinking water. The water treatment facility treats an average of 30 MGD throughout most of the year, with a peak of 50 MGD in the summer.
The Mountain Regional Water District is a Special Service District of the county that was established by the Summit County Commission in 2000 to regionalize water service by consolidating several public and private water companies.
When Linda Mullen took over as water superintendent in Burnsville in 2007, the city was in the process of adding surface‐water treatment to its existing plant. Burnsville began purchasing water from the nearby Kraemer Mining and Materials quarry, both to supplement its supply and to help the quarry meet discharge permits.
A San Jose Water Quality Engineer said, "“I wasn’t convinced that PSI’s Monoclor™ chloramine dosing system would solve our problems after several failed attempts to improve residual, but with PSI offering a trial including installation, operation, and troubleshooting for three months, San Jose Water decided to invest the necessary resources to pilot this system.
Hendersonville Utility District (HUD) serves one of the most populous suburbs of Nashville, Tennessee.
The removal of contaminants from public drinking water systems in the US is mandated by the Environmental Protection Agency’s (EPA) National Primary Drinking Water Regulations. These are legally enforceable standards that protect public health by limiting the levels of contaminants in drinking water. Similar regulations are managed by agencies worldwide to protect their citizens from drinking water contamination.
There are a plethora of drinking water contaminant removal technologies that public and private water systems use to comply with the EPA’s drinking water regulations. These include reverse osmosis, membrane, nanofiltration, ultrafiltration, chlorine disinfection, UV disinfection and Ozone-based disinfection practices.
The EPA’s list of drinking water contaminants is organized into six types of contaminants and lists each contaminant along with its Maximum Contaminant Level (MCL), some of the potential health effects from long-term exposure above the MCL and the probable source of the drinking water contaminant.
The six types of contaminants are microorganisms, disinfectants, disinfection byproducts, inorganic chemicals, organic chemicals and radionuclides.
Examples of microbiological, organic contaminants are Cryptosporidium and Giardia lamblia. Both of these microorganic pathogens are found in human or animal fecal waste and cause gastrointestinal illness, such as diarrhea and vomiting.
A common disinfectant used in municipal drinking water treatment to disinfect microorganisms is chlorine. The EPA’s primary drinking water regulations require drinking water treatment plants to maintain a maximum disinfectant residual level (MDRL) for chlorine of 4.0 milligrams per liter (mg/L). Some of the detrimental health effects of chlorine above the MCL are eye irritation and stomach discomfort.
Similarly, byproducts from the chlorine-based disinfection methods used by public water systems to remove contaminants can be contaminants in their own right if not removed from the drinking water prior to it being released into the distribution system. Examples of disinfection byproducts include bromate, chlorite and total trihalomethanes (TTHMs). Not removed from drinking water, these disinfection byproducts can increase risk of cancer and cause central nervous system issues.
Chemical contamination of drinking water can be caused by inorganic chemicals such as arsenic, barium lead, mercury and cadmium or organic chemicals such as benzene, dichloroethane and other carbon-derived compounds. These chemicals get into source water through a variety of natural and industrial processes. Arsenic for example is present in source water through the erosion of natural deposits. Many of the chemical contaminants are derived from industrial wastewater such as discharges from petroleum refineries, steel or pulp mills or the corrosion of asbestos cement water mains or galvanized pipes.
Radium and uranium are examples of radionuclides. Radium 226 and Radium 228 must be removed to a level of 5 picocuries/liter (PCI/L) and Uranium to a level of 30 micrograms/liter (30 ug/L).