In late 2005, the City of Newberg, Oregon, decided to upgrade their water treatment plant disinfection process from gas chlorine to on-site hypochlorite generation (OSHG) in an effort to simplify operations and increase operator safety. The plant produced an average of 2.5 million gallons per day (MGD), with a peak capacity of 5 MGD.
Santa Margarita Water District (SMWD), located in southern California’s Orange County, between Los Angeles and San Diego, provides drinking water and wastewater services to over 165,000 residents and businesses. SMWD approached UGSI Solutions about a Polyblend® Polymer Activation System trial at their 3 A Water Reclamation Plant.
In one of Pennsylvania’s three original counties, water has played an integral – even historic – role in the region’s development.
Groundwater in Southeastern coastal Virginia is depleting due to over-drafting without intentional replenishment. This phenomenon makes the Potomac aquifer susceptible to saltwater intrusion as well as land subsidence, or the gradual settling or sudden sinking of the earth’s surface. The Hampton Roads Sanitation District responded to these issues by using groundwater augmentation as a way to recharge the aquifer, prevent saltwater intrusion, and potentially increase ground elevation.
The objective of the pilot study was to demonstrate “proof of concept” if coagulation followed by filtration was a viable technology to remove arsenic in water from Well No. 6 when raw water arsenic levels are so high, >70 ppb. Preparations were made to reduce the pH of the raw water if it was required. Also, two unique arsenic adsorptive medias were evaluated as a final polishing step to the effluent of the coagulation/filtration process.
Reverse osmosis, or RO, is one of the finest technologies to purify water containing high total dissolved solids (TDS) levels of more than 500 ppm. Reverse osmosis plant exporters explain the technology as a separation technology where dissolved and invisible impurities in water are separated with the help of semi-permeable membrane or RO membrane that works under high pressure.
The Golden State Water Company selected WRT’s Z-92® Uranium Removal treatment system to reduce high concentrations of uranium in a single treatment system for three wells located in the Morongo Valley of California. Since installation of the Z-92® Uranium Removal treatment system in Morongo del Sur in 2013, the uranium levels are being reduced to levels below the Maximum Contaminant Level (MCL).
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.
Bathurst is the home of the Bathurst 1000 Race, the largest NASCAR-style “touring car” race in Australia. On race day, tens of thousands of additional visitors tax the capacity of the Bathurst 5 million-gallon-per- day wastewater treatment plant. The diligence and capability of the treatment staff allows the plant to meet the challenge every year.
As one of the top 20 American research institutes in the United States, Texas A&M has hundreds of laboratory facilities on its campus where a variety of proven water treatment technologies are used to control the quality of the water used in research.
A single WRT Z-92® Uranium Removal treatment system was selected by the City of Grand Island, NE to remove high concentrations of uranium in three city wells. When the Z-92® Uranium Removal treatment system was installed in 2012, it was the largest uranium treatment facility in the nation. The high uranium in the raw water source is consistently being reduced to levels below the Maximum Contaminant Level (MCL).
PFCs are turning up in source waters and news cycles, drawing both public and regulatory concern. How pervasive is this group of emerging contaminants — namely PFOS and PFOA — and how might the saga unfold for utilities?
The 34 MGD Otay Water Treatment Plant in San Diego, California serves a population of approximately 200,000. It is a conventional treatment plant that uses coagulation, flocculation, sedimentation, filtration and disinfection. The plant receives raw water from two different sources — imported water from the Colorado River and runoff water from three local reservoirs.
San Jose Water Company (SJWC) provides drinking water for over a million people in the greater San Jose Metropolitan region and is a recognized leader in drinking water treatment and distribution system water quality management. With over 90 water storage facilities in service, planned maintenance and rehabilitation of capital assets is a key component of SJWC’s CIP program.
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).