Ensuring the quality and safety of drinking water across the U.S. EPA-monitored 155,000 public water systems has become a national issue.
The financial cost to maintain their ozone equipment, and increasing scarcity of replacement parts for their ozone generator, motivated a utility in Springfield, MO, to upgrade their ozone system. Read the full case study to learn how the plant assessed the energy cost of a sidestream ozone injection system compared to that of a turbine mixing design and showed that the Mazzei retrofit design reduced the energy cost of ozone contacting by an average of 69.2% under all plant flow conditions.
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.
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.
Chromium is a naturally occurring metal common in the earth’s crust. There are multiple forms of chromium, and one form, called chromium‐3, is actually a required nutrient for human health, in the right amount.
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.
The City of Somersworth has a historical background dating back to the early 1900s when it became the first community to start using chlorine to disinfect it’s drinking water.
Ultrafiltration (UF) membranes have already gained worldwide acceptance in the treatment of drinking water for their removal of chlorine resistant pathogens such as cryptosporidium. Tertiary treatment with UF has been established, although with a lower level of knowledge and number of installations. This paper will discuss the performance of hollow fiber UF/MF membrane modules in treating tertiary effluent, and the subsequent performance of the downstream RO membranes.
What would happen if there was an emergency in the U.S. that caused radioactive material to contaminate drinking water supplies? What steps could your utilities and government take?
Rapid detection of changes in water quality is critical in water delivery systems, wastewater treatment, and industrial plants for process optimization, environmental regulatory requirements, and consumer health.
For drinking water treatment plants (DWTPs), the EPA’s Disinfection Byproduct Rule (DBP) is a way of life. Unfortunately, for many facilities the equipment and operations haven’t evolved with the regulation mandates, leaving facilities in a tough spot. For a DWTP in Douglas County, KS, its challenges with accurate TOC measurement and testing, along with expensive calibrations and extended downtime with its prior TOC analyzer led it to trialing the Hach QbD1200 TOC Analyzer. Read the full case study to learn more.
Managed by the private, non-profit South Jasper Water Supply, Buna, Texas’ water system contains 91 miles of un-looped distribution pipe with historical water losses of up to 30%. A small operations team is responsible for monitoring two water plants, reading 700 meters, repairing leaks, and flushing water to control the water quality. In an effort to spend less time manually flushing hydrants and focus more time on repairing leaks to reduce non-revenue water loss, South Jasper Water Supply purchased and installed two (2) Hydro-Guard® HG-1 Basic/S Flushing Systems.
Our nation’s record of progress in advancing public health under the Safe Drinking Water Act is significant.
Water, water is everywhere, but we need more drops to drink. The primary mission of the recently founded Nanotechnology Enabled Water Treatment (NEWT) Center, a consortium based at Rice University and led by environmental engineer Pedro Alvarez, is to produce more drinkable drops where they're needed the most.
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).