Hendersonville Utility District (HUD) serves one of the most populous suburbs of Nashville, Tennessee.
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.
With 100 years of service history, Austin Water has seen enormous change in its 540 square miles of service area. Planning for the next 100 years has city and utility planners considering a diversity of sources, system resilience, and sustainability while being mindful of conservation goals. In the city’s newest water treatment plant, WTP4, Austin Water was able to combine those planning elements into a state‐of‐the‐art treatment plant. The plant, which is located on Lake Travis, is capable of treating 50 million gallons a day (MGD) with the ability to expand to 300 MGD.
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 Mazzei Sidestream Venturi Injection – Pipeline Flash Reactor System provides a feasible alternative for dissolution of ozone at the Clark County Water Reclamation District (CCWRD) in Las Vegas, because it allowed for flexibility in basin design to meet geographic site constraints.
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.
The Water Environment & Reuse Foundation introduces a “bundle of research” to help direct potable reuse and its practitioners reach full potential.
If you thought reverse osmosis was the one and only choice for potable water reuse, think again. Ozonation followed by biological activated carbon (ozone-BAC) is more suited to inland communities and may be better at removing chemicals of emerging concern (CECs).
The manufacturing of soda ash from Trona is a multi-step process that results in the production of a waste liquor that contains significant levels of organic contamination.
Pilot testing was conducted to evaluate the relative performance of 4 filter media, including Ceraflow-50, as part of a reduction coagulation filtration (RCF) treatment process for the removal of hexavalent chromium (Cr(VI)) from groundwater. This evaluation was conducted at multiple well sites for a water utility in California.
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.
A water utility in the Midwest USA uses Monochloramine treatment in their two surface water treatment plants to disinfect raw water and establish residual disinfectant prior to discharge to their distribution system.
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.
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 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).