Like many municipalities, Hamilton, Ontario, is wary of harmful algal blooms and toxic cyanobacteria. To mitigate the threat and protect drinking water, a proactive, risk-based plan was developed.
Interested in converting to biological drinking water treatment? Here’s what you need to know.
Enactment of the Long Term 2 Enhanced Surface Water Treatment Rule and the Stage 2 Disinfectant-Disinfection Byproduct Rule (D/DBPR) will require both large and small drinking water utilities to reduce total organic carbon (TOC), Cryptosporidium, and disinfection byproducts (DBPs) in the treated drinking water distributed to the public.
Examples of medicines and personal care products detected in water include antimicrobial materials found in toothpastes and hand soaps, fragrances, prescription medicines, bug sprays, and sunscreen. Concentrations of these substances detected in water are typically very small and are currently not regulated at the federal level in the U.S.
The groundwater that a southern Louisiana water utility supplies to local residents has traditionally carried a high amount of organic material and color. In the past, the organics were oxidized and broken down by chlorination, but this practice had gone out of favor due to production of disinfection by-products (DBPs) such as Trihalomethanes (THMs) and Haloacidic Acids (HAAs).
The city of Fort Lupton a growing Front Range community located along the South Platte River in Colorado, began operation of a new 5 MGD (18.93 MLD) membrane filtration system in 1997.
Ensuring the quality and safety of drinking water across the U.S. EPA-monitored 155,000 public water systems has become a national issue.
Recently, cyanobacteria and cyanotoxins have become a high profile drinking water quality concern in both the United States and abroad. The combination of weather conditions, agricultural phosphate runoff, and other factors has produced water conditions that have favored the formation of cyanobacteria in surface water supplies.
The TrojanUVPhox™ installation at Tucson's Advanced Oxidation Process Water Treatment Facility treats 1,4-dioxane and produces water that is blended and then treated at the neighboring Tucson Airport Remediation Project facility. This purified water is supplied to nearly 50,000 end users.
With people flocking to the trendy Texas metropolis, Austin needed a new treatment plant to sustain its growth — but a “sensitive” touch was required to complete the project while protecting the environment.
A Nebraska reservoir was experiencing toxic algae in its water. Constructed by the U.S. Army Corps of Engineers (COE) primarily as a flood control reservoir with recreation and irrigation as secondary uses, the reservoir has a surface area of 700+ acres with an average depth of almost 12 feet.
California’s inland communities have been hit hard by four years of drought, lower groundwater levels, and reduced allocations from the State Water Project.
In February 2010, the Dempsey E. Benton Water Treatment Plant (DEBWTP) added 16 million gallons per day (MGD) of capacity to the water utility operated by the city of Raleigh, North Carolina.
Eden Isle is a residential subdivision on a peninsula located on the beautiful Greers Ferry Lake. Many homes located in this area are occupied exclusively in the summer.
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).