In Canada and the western United States, long treated water transmission lines are frequently utilized to convey potable water to rural communities. These long transmission lines combined with chlorine for water disinfection can often create the requisite conditions for the formation of undesirable disinfection-byproducts (DBPs). One of the most common DBPs is a family of volatile compounds called Trihalomethanes (THMs) which are regulated in Canada to a level of 100 ppb (part-per-billion) annual average and in the US to a level of 80 ppb.
According to a recent survey by the Water Quality Association, 30 percent of residential water utility customers are concerned about the quality of the water coming out of their taps, which is likely one reason that American consumers spent upwards of $16 billion on bottled water last year. It’s also why the water purifier market continues to experience extreme growth and is expected to garner $45.3 billion by 2022 as companies in the space look to better cater to consumer demand.
Located in northern California, the Coastside County Water District (CCWD) provides treated water to the scenic town of Half Moon Bay and several unincorporated communities in the area. The system is served by two treatment plants, the Nunes Water Treatment Plant (4.5 MGD) and Denniston Creek Water Treatment Plant (1.0 MGD) and water is distributed through about 100 miles of transmission and distribution pipe.
Upper Deerfield Township, NJ relies on groundwater from four wells measuring 120 to 160 feet deep. The water is treated at two treatment plants with a capacity of 2.2 MGD and then pumped out to the distribution system with approximately 750,000 gallons of storage. Since the deep groundwater is hard, operators add lime to the finished water to raise the pH to reduce hardness.
In 2012 Long Beach Island, New Jersey, was pummeled by the catastrophic storm surge of Hurricane Sandy. Three of the town's four water plants were badly damaged. Plans were made to rebuild the facilities to higher standards to withstand potential storm impacts.
The City of Paramount conducted a pilot study for arsenic, manganese and iron treatment system at their Well 15 site. The onsite pilot test was designed to demonstrate the performance of the Loprest Water Treatment Company treatment process proposed for the new treatment plant.
It's spring and the algae are in bloom, but harmful algal blooms are far from the only threats to drinking water. Fortunately, there are advanced treatment technologies to handle some of the most persistent contaminants today, including algal toxins, Cryptosporidium, and 1,4-dioxane.
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.
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.
A chemical company which specializes in Clean-In-Place (CIP) systems, contacted Mazzei to discuss the use of ozone as an alternative to peracetic acid sanitation or heat sterilization at their customers’ plants.
Purissima Hills Water District (PHWD), a county water district, provides chloraminated water service to two-thirds of the town of Los Altos Hills, adjacent to the city of Palo Alto in Northern California. With remote tank locations, low population density (6,800 people) and low water demand (1.61MGD), PHWD is constantly challenged to maintain consistent disinfectant residual levels while simultaneously balancing the safe delivery of chemicals to its tank site at an affordable cost.
The city of Buhl, Idaho, obtains all of its drinking water from groundwater sources through multiple wells. Prior to 2009, the city did not treat the groundwater but only added chlorine in the form of bulk 12.5% sodium hypochlorite to provide a disinfectant residual. A combination of factors including: changes in EPA and state DEQ regulatory requirements, growth of the residential population and growth of the industrial food processing customers forced the City to build a new water treatment plant to provide filtration to address the naturally occurring arsenic present in the groundwater.
Loprest has been designing and fabricating manganese removal systems using manganese greensand for over forty years. Drawing on that experience; filtration rates, run times, backwash procedures, chemical dosage rates, etc. are all established by theoretical calculations and history. Therefore, Loprest’s goal in this pilot study was to conduct uninterrupted operation per bid testing procedures and document the results.
With virtually no local water sources available for use, the City of San Diego relies on water from the Metropolitan Water District, which imports its water from the Colorado River and the California State Water Project. The two massive water projects bring water from other watersheds and regions hundreds of miles to the north and east.
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).