Once in a while, an incident involving water quality arises in a United States community that sets off alarms for the water consumers and sends water utility operators in a scramble to mitigate the problem.
To that end, water utility managers nationwide are engaged in ongoing efforts to ensure water quality from the source to the tap.
When a city produces what is considered some of the best water to be consumed, it endeavors to maintain that quality.
The city of Hamilton, OH, in 2010 had earned the title of “The Best Tasting Tap Water in the World” at the 2010 Berkeley Springs International Water Tasting Competition, followed by the 2012 “Best of the Best” Award from the American Water Works Association –Ohio Section, for the Best Tasting Tap Water in Ohio.
The city of Hamilton owns and operates two water treatment plants. The South Water Treatment Plant is the primary provider of tap water for the city with a capacity of 40 million gallons per day (MGD). The North Water Treatment Plant has a 6-MGD ability and serves as a backup and peaking plant, as well as a raw water and cooling water source for the city’s North 3rd Street Electric Generating Plant.
John Bui is the director of underground utilities for Hamilton, and is charged for overseeing the efforts to continue to provide quality water to the city’s 2,400 service connections.
The city’s raw water source is the Great Miami Valley Buried Aquifer. The city utilizes 21 deep wells to extract water and treats it with a chlorine dioxide disinfectant process. Hamilton’s water system encompasses more than 289 miles of water mains and provides an average of more than 18.5 MGD to approximately 25,000 customers in Hamilton and portions of Butler County.
Water samples are collected from wells throughout the region twice a year and monitored for contaminants, says Bui. “Our program also has inventory from companies of chemicals that are hazardous materials so that we know what we have in our region as well,” he adds.
In 2012, Hamilton was approached by analysis equipment manufacturer Palintest to get involved in a study of a new system it was planning to release on the market. As a result of the success of the study, Palintest has recently introduced an alternative method for disinfection residual testing, the ChlordioX Plus instrument method. The instrumentation allows chlorine dioxide disinfectant users to test for chlorine dioxide and chlorite residuals. Measuring chlorite is a regulatory requirement when using chlorine dioxide as a drinking water disinfectant.
The ChlordioX Plus has been designed to provide full analysis and control for all samples, including solutions containing free chlorine.
The ChlordioX Plus method was approved by EPA as an alternative testing method for disinfectant residuals in the federal register.
Using disposable ampermetric sensors, the ChlordioX Plus is designed to provide portable and user-friendly determination of chlorite in water samples.
“We volunteered because chlorine dioxide and chlorite are contaminants that we are required to monitor at the plant at least once a day and in our distribution system once a month,” says Bui.
Hamilton has been using another water-quality testing system, which required that the analyst be experienced with the instruments to perform the test, which takes 45 minutes to an hour to run the sample, says Bui.
“With the ChlordioX Plus, it’s pretty simple. Everything is built into this sensor where you just follow a few simple steps, and it does all of the work of all of the calibration and the measurements and gives you the results,” he says. “If you do one test and follow step by step from start to finish, it’s about 10 minutes. But if you already know how to do the test, you can shorten the timeframe down to five to seven minutes a sample.”
Bui says the ChlordioX Plus is also more accurate. “You follow it step by step. It’s very hard to make a mistake,” he says. Hamilton is awaiting Ohio EPA to approve the method and certify its lab to utilize it.
“With this new method, you don’t really have to have a chemistry background or laboratory experience–a half hour of training, and anybody can do it,” says Bui.
Hamilton’s 2013 Water Quality Report indicated the Ohio EPA completed a study of Hamilton’s North and South Wellfields to determine contamination susceptibility for both sources of drinking water. According to the study, the aquifer that supplies water to Hamilton’s wells has a high susceptibility to contamination based on the lack of a protective layer of clay, the shallow depth of the aquifer, and the presence of significant potential contaminant sources in the protection area.
Reverse osmosis facility
An aerial shot of North Port’s reverse osmosis and surface water treatment plant
“We have a source water protection program in place, and we monitor the source of contamination carefully,” says Bui. The city is a member of the Hamilton to New Baltimore Groundwater Consortium, which, in concert with the Ohio Departments of Agriculture and Natural Resources and the Miami Conservancy District, studies groundwater capabilities, provides information on water quality and availability, and facilitates future water usage planning.
The Consortium also is responsible for management, contingency planning, public education, and groundwater monitoring of the Wellhead Protection Program.
Bui acknowledges that while contaminated drinking water incidents that have occurred elsewhere in the county are disconcerting, “we are fortunate that we have good groundwater and our wells are dispersed throughout the city and not concentrated in one place. If there’s contamination in one area close to one well or two, we can shut those wells down and use other wells in the system.”
There are a few challenges that Bui faces in his mission –meeting new regulations is one.
“The EPA continues to put out a new unregulated contaminants list that water utilities have to monitor,” he says. “We are fortunate that in our region, we haven’t encountered any of these contaminants that we have to treat for or change the treatment techniques to remove it just yet.”
Bui adds that it is “increasingly more difficult for many public water utilities to find money to fund aging infrastructures while maintaining affordable rates for our customers. “We have streamlined our operations and do more with less while meeting all regulatory obligations, service levels, sustainability, and financial goals,” he adds. “We are trying to stretch the dollar further for our ratepayers by eliminating unnecessary spending and making smarter investments in our infrastructures and O&M.”
North Port, FL
In April 2013, the City of North Port, FL, launched its latest efforts to protect its water supply, which services 18,000 water customers. North Port had relied on a conventional surface water coagulation-sedimentation filtration process to service its 18,000 water customers.
That process is unable to provide potable water that met secondary regulatory requirements during the dry season, when source water supplies have elevated levels of sulfate and total dissolved solids.
The city purchased water from a regional source to meet needs during those periods. Additionally, the Florida Department of Environmental Protection (FDEP) issued a secondary water quality operating variance deadline on the city.
North Port obtains the majority of its raw water supply from the Myakkahatchee Creek, which originates in eastern Manatee County and flows adjacent to its water treatment facility. An alternative water source used as emergency backup is the Cocoplum Waterway. The raw surface water is treated at the North Port surface water treatment facility.
The City of North Port also purchases water from the Peace River Manasota Regional Water Supply Authority, which is treated at the Peace River Water Treatment Facility in Desoto County. “We do have an interconnect that if something were to happen, we could shut our plant off and purchase all of our water from that authority,” says John Evano, superintendent of North Port’s water treatment plant.
The city’s recent efforts were enacted to ensure water reliability. McKim & Creed, an engineering and geomatics company, served as the engineer on the project to help the North Port Myakkahatchee Creek Water Treatment Plant (WTP) improve its water quality through the Myakkahatchee Creek WTP Reverse Osmosis (RO) Reliability Project.
The $8.9-million RO Reliability Project maximizes the utilization of the existing plant while having brought online six new intermediate aquifer wells that draw water from the Upper Floridan Aquifer. These produce significant quantities of water with minimal localized draw down impacts and a new surface water intake system.
Additionally, water from a new 1.5-MGD Aerex reverse osmosis treatment facility is treated and blended with treated water from the existing Myakkahatchee Creek WTP. A new intake system on the Cocoplum Canal was designed by Carollo Engineers to increase surface water source reliability.
The 8,000-square-foot treatment building houses new filtering and the RO equipment, a state-of-the-art control room and space for support operations, allowing the city to produce water year-round under a wide range of conditions, notes Street Lee, P.E., McKim & Creed senior vice president.
McKim & Creed’s instrumentation and controls specialists designed new control systems and the interface with the existing treatment plant and then developed the programming operator interface, the plant’s programmable logic controllers and the SCADA (supervisory control and data acquisition) database, configured the computer hardware, and trained the city’s operators to use the controls system.
McKim & Creed engineers developed a blending approach to improve both water quality and quantity. The water from the intermediate aquifer wells is treated at the new RO treatment facility and then blended with treated water from the Myakkahatchee Creek Water Treatment plant.
The blending occurs in the ratios necessary to meet all regulatory requirements, including sulfates and total dissolved solids, and enables the North Port Utilities Department to operate the existing facility full time, even during periods when the surface water supply for the existing plant is of insufficient quantity or of poor quality.
Lee points out that North Port’s setup not only solves its water-quality issues, but also blending the existing surface water with the higher-quality water is a way to achieve the full permitted quantity from the site. The system was designed to give North Port a local, drought-tolerant water source to eliminate reliance on purchased water and the energy required to pump water from longer distances.
North Port analyzes its water daily, Evano says. “We monitor the process continually while we are treating the raw water. We have certain tests that we log in,” says Evano. “We’re set up on a two-hour schedule. That could change depending on if we’re having any issues with the quality, but we’re constantly monitoring. We have online monitors that are always giving us data. We visually monitor the process at all times during the treatment process. We do grab samples every two hours at different spots in the system, too.”
Through the combination of reverse osmosis and conventional surface water treatment processes, the surface water treatment and color removal process consists of taste and odor control, coagulation, flocculation, sedimentation, filtration, disinfection, and stabilization as primary water treatment techniques.
The absorption process is used at the North Port plant to control taste and odor in the surface water. Powdered activated carbon (PAC) is added to the raw water prior to the flash mix chamber at the beginning of the treatment plant.
Aluminum sulfate (alum), a coagulation chemical, is added to the flash mixing chamber. “It grabs all of the particles in the water–the organics, even the carbon–and it makes a heavy floc formation,” says Evano. The carbon particles, along with other particles–including color–bind with the alum and form heavy floc, which is removed by sedimentation in a large basin.
Remaining particles are removed by conventional sand, anthracite coal, and gravel filtration. Sodium hypochlorite and ammonia are used for disinfection after filtration. Sodium hydroxide (caustic) is used for stabilization (PH control).
The source water for the reverse osmosis treatment process is pumped from intermediate aquifer wells and into a series of membranes to remove salt and other effluent materials from the water molecules.
After purification, the water is run through an aeration odor control process to remove hydrogen sulfide. Chlorine is added as a disinfectant prior to blending with the treated surface water before distribution.
North Port uses a great deal of Hach water testing equipment. Dead ends are one of the biggest challenges the water utility faces, Evano says.
“We have a lot of dead ends that we battle because we’re such a large land area, and we have to do a little extra flushing more than other systems because of it,” he notes. “In the summertime, the warmer temperatures give us a little fit sometimes. Making sure the water is flushed through the dead ends helps our quality.”
Ever since the installation of the reverse osmosis plant to blend the water with the surface was, North Port’s water quality has improved, Evano says. “The hardness and Total Dissolved Solids have gotten better,” he adds. “Our quality is much better than it was years ago.” The city has a public relations representative who tours schools, talking to students about how the water is treated. The city also offers plant tours.
The city of Seattle’s drinking water comes from rain and snowmelt in two protected surface water sources in the Cascade Mountains: the Tolt River and the Cedar River.
The watersheds are carefully managed to support and supply clean drinking water to 1.4 million people in the greater Seattle area.
The Cedar River Municipal Watershed, owned by the city of Seattle, covers 90,638 acres and supplies about 70% of the drinking water. The South Fork Tolt Watershed is smaller than the Cedar River Watershed but still an essential second supply in the Seattle Public Utility’s (SPU) system. Located in the foothills of the Cascades in east King County, it supplies about 30% of the drinking water.
Since drinking water flows at all times, part of the challenge “is ensuring water quality is great every time a customer turns on the tap,” says Wylie Harper, P.E., drinking water quality manager. That goal is accomplished in multiple ways, he says.
“First, we start with a great source,” says Harper. “Our protected watersheds have no industrial or agricultural activities. The watersheds’ forest and maintenance roads are actively managed. We monitor water quality in our sources by sampling and testing throughout the year.
“Secondly, the water is treated at state-of-the-art treatment facilities by certified operators who continuously monitor each step of the treatment process. We also have staff assigned to collect samples throughout the distribution system and analyze them at our accredited laboratory, which operates seven days a week.”
There are three drivers that help determine the appropriate water-quality monitoring approach in Seattle: regulations, health protection, and customer confidence.
“Regulations establish thresholds for microbial, chemical parameters, and radiological analytes as well as determine monitoring and reporting frequency,” points out Harper. “The Safe Drinking Water Act sets forth multiple rules, such as total coliform, lead and copper, disinfection and disinfection byproducts rules, which prescriptively specify where, when, and how to monitor.”
SPU also helps ensure customer health protection by monitoring operations with non-regulatory testing as well. “For example, we routinely monitor water quality our storage tanks and reservoirs, we sample after installation of new water mains, and we sample if there’s a significant main break,” says Harper. “SPU monitors algae and nutrients in our sources’ waters, too.”
To promote customer confidence, SPU regularly conducts a taste and odor panel to help ensure water tastes and smells good, Harper says. “This is primarily aesthetic, but goes a long way toward maintaining customer confidence,” he adds.
Harper notes that existing drinking water regulations have become more stringent over the years. “I expect that to continue as capabilities for treatment and analysis become more advanced,” he says. “It means being prepared to sample and test for more parameters, update equipment as appropriate, and maintain a competent, qualified staff to carry out the work.”
Harper points out that Seattle water meets or is better than federal standards for drinking water quality. Daily, more than 50 samples are tested before and after treatment at SPU’s water quality lab for a variety of waterborne disease indicators, minerals, chemicals, and contaminants.
The Tolt Water Treatment Facility, which started operation in 2001, treats up to 120 million gallons per day. The treatment process is as such:
- Ozonation: adding ozone gas, a powerful disinfectant which destroys Cryptosporidium, Giardia, bacteria, and viruses and aids the filtration process
- Coagulation and flocculation: gently stirring the water with small doses of chemicals to bring small particles together to form large particles that can be more easily filtered
- Filtration: removing the suspended solids by passing the water through a 6-foot deep bed of anthracite (crushed coal)
- Chlorination: adding a secondary disinfectant to provide continued protection in the distribution system against microbial contamination
- Fluoridation: adding fluoride to help prevent tooth decay. Seattle added this to comply with a public vote in November 1968.
- Corrosion control treatment: adding lime and carbon dioxide to increase the pH of the water, making it less acidic and less corrosive to piping and plumbing materials
The Cedar Water Treatment Facility started operation in 2004 and treats up to 180 million gallons per day.
The treatment process for the Cedar supply is:
- Ultraviolet (UV) light disinfection: a second disinfectant used to inactivate microbial contaminants such as chlorine-resistant Cryptosporidium and Giardia.
- Corrosion control treatment
The city’s infrastructure ranges in age from new to nearly a century old, notes Harper. “The treatment facilities are quite new and certainly help us provide great quality water,” he adds. The transmission lines, distribution mains, and storage facilities vary in age, with portions of the distribution system having been installed in the early 1900s.
“Much of this cast iron pipe is still in very good condition,” says Harper. “One of the challenges is assessing its condition and likelihood of breaking or leaking. While the age of the infrastructure doesn’t directly affect water quality, if it were to break or leak dramatically, the associated response and repair must be done promptly and carefully to make sure contaminants aren’t introduced.”
SPU has not found anything new in the water that hasn’t been there in the past, Harper says. “As analytical methods and testing instruments have become more refined and sensitive over the years, we are able to see trace concentrations of analytes that have always been there but couldn’t previously be detected,” he says. “For example, naturally occurring metals or minerals at part per billion levels can be seen.
“We don’t find herbicides, pesticides, or pharmaceutical compounds due to the nature of our watersheds. New compounds or contaminants are periodically reviewed and potentially added to existing regulations by EPA.”
Contingency plans to address the potential that the water is compromised are to a great extent preventative in nature, says Harper. “We have watershed protection plans, security protocols, and operating procedures designed to protect the system and water quality,” he says. “If the water was compromised at one location, there’s redundancy built into much of our system. We can send Tolt water further south or Cedar water further north if needed. Both treatment facilities can have portions operated as separate “˜trains.'”
SPU also can change valve configuration in portions of the distribution system to move water differently if needed, he adds. “From a planning perspective, SPU maintains continuity of operations plans for a variety of scenarios and has incident action plans to respond to potential emergency events,” says Harper.
SPU addresses public education in a variety of ways. “We send an annual water quality report to all of our customers,” says Harper. “We have a call center to field day-to-day questions from the public. SPU has water-quality inspectors who respond to customer water quality calls and complaints. They’ll investigate and sample if warranted.”
The Cedar River Watershed has an education center that’s open to the public. “It’s a great learning opportunity for any visitor,” says Harper. “We also have quite a lot of good information on our website. If there’s a unique or neighborhood-specific water system event such as repair or construction, our communications staff will tailor information and education to those specific customers.”
In mid-August, Blue Ocean Sciences (BOS), a clean water technology company in Santa Barbara, CA, partnered with Margo Pellegrino, an ocean paddler and conservationist, in a nine-day, 300-mile outrigger paddling trip along the Delaware River from Trenton, NJ, to Newark, NJ’s public boat launch and park on the Passaic River.
The Delaware’s 13,539-square-mile watershed is only about four-tenths of 1% of the continental US land area, but it supplies water to 5% of the nation’s population–more than 15 million people, according to the Delaware Riverkeeper Network. The Delaware is the longest undammed river east of the Mississippi, flowing freely for 330 miles from New York state, through Pennsylvania, New Jersey, and Delaware to the Atlantic Ocean.
“The Delaware River is a vitally important drinking water supply–all of the way from the headwaters located in New York State where New York City gets a large portion of its drinking water supply unfiltered, down to the city of Philadelphia and south New Jersey communities. There are multiple water intakes,” says Maya K. van Rossum, director of the Delaware Riverkeeper Network.
Using the Hope2o water analysis kit donated by Blue Ocean Sciences, Pellegrino took 100 water samples for later in-depth analysis of water quality in several inland waterways to raise awareness about regional water contaminants.
Throughout the journey, Pellegrino met with various organizations such as Clean Ocean Action, NY/NJ Baykeeper, Raritan Baykeeper, and the New Jersey Sierra Club. She is an ocean activist who has been addressing multiple water issues, including disposable plastics, the flooding and vulnerability of riverfront and coastal structures, and the contamination of various bodies of water such as oceans, rivers, and underground aquifers.
Pellegrino’s journey took her along many areas accessible only by water vessels. In using Hope2o water analysis kits, accurate data also will be available as an integrated and easy-to-read digital map of regional water contaminants.
The Hope2o water analysis kit has the capability of testing for a wide range of pesticides, pharmaceuticals, heavy metals, and organic chemicals in both salt and freshwater. The water analysis kit is designed to be simple to use and capable of detecting chemicals down to the part per trillion (ppt) given the long-term detrimental health effects of consuming contaminants, the company points out.
Of the reason Pellegrino undertook her journey, she says: “We’ve been seeing a lot of signs and a lot of issues with our water right now. In New Jersey, we are going in such a direction where we can make things dramatically worse and put our water at risk or we can take the bull by the horns and do some of the hard stuff that’s really necessary and turn it around.”
Pellegrino hears the criticism that change may impact jobs. She disagrees. “There are huge amounts of jobs involved in correcting our water today,” she says. “Especially when you look at combined sewer outfalls. Those are a mess. Every time we have a flood situation, which is happening more frequently especially in places like Camden, that flood water is especially dangerous–not just for those who don’t know how to swim, but because of what is in the water.”
Pellegrino–who was inspired by hearing a talk on unregulated compounds found in drinking water sources–says her long-term goal is to get people thinking about water resources. “I firmly believe that once we have people thinking about that more, we’ll have a greater outcry for the protection of our water.” She also says such conversations paved the way for the Clean Water Act.
“We had gotten ourselves into such a state and we were able to fix things,” she says. “We have a list of regulated compounds. But now we’re seeing more and more unregulated compounds that we don’t even know what they do and what kind of long-term health effects they will have on us after years of chronic exposure.
“I’m not so concerned about a one-shot deal where you’re exposed to contaminants because your kidneys, bladder, and liver are pretty good at taking care of that, but chronic long-term exposure is a serious thing to worry about.”
Pellegrino points out that there are male fish with female attributes discovered in the Potomac River. “We have got to get a handle on what the pharmaceuticals ending up in our water supply are doing.”
She is calling for the revising of the Clean Water Act, and says that reaction to her advocacy has been generally positive. “It’s really a no-brainer: do you want healthy, clean water or do you want dirty water? Do you want a healthy ocean or a dirty ocean? That’s a perfect way of looking at it, and you can build from there. Once you start killing off a lot of smaller populations because of pollution or ocean acidification–which is a mirror of climate change–it’s not too hard to imagine us humans at some point having problems as well.”
Andrea Neal shares these concerns. She is founder and president of Blue Ocean Sciences, supplier of the test kit Pellegrino used. Neal is also an expecting mother, which amplifies her study into the potential effects (both short and long term) that low-level contaminants such as pharmaceuticals, pesticides, organic chemicals, heavy metals, and hormones can have on unborn children. She has a Ph.D. in molecular biochemistry and more than 15 years of experience working with environmental toxins, water contaminants, and remediation on all levels. Sometimes called the “Water Doctor,” Neal served the Principal Investigator of Project Kaisei in 2009 and was one of the Principal Investigators for the 2011 Lone Ranger Transatlantic Investigation of Marine Pollutants with the Schmidt Ocean Institute. She is also the Science Advisor for Jean-Michel Cousteau’s Ocean Futures Society.