Local governments await final water regulations
As the U.S. Environmental Protection Agency prepares to finalize its Enhanced Surface Water Treatment Rules and its Disinfectants/Disinfection By-products Rule (D/DBPR), cities and counties are beginning to understand the changes necessary for their water utilities. Tighter contaminant standards, as well as limitations on the use of disinfectants, are likely to prompt alterations ranging from minor operational tweaks to new treatment plant construction.
More of a good thing Every day in the United States, approximately 60,000 water utilities produce and distribute more than 20 billion gallons of safe, potable water. The millions of customers who enjoy that service owe their health in part to the Safe Drinking Water Act (SDWA).
Originally passed in 1974, the SDWA established EPA as the principal regulator for local water suppliers, and it directed the agency to begin collecting data about drinking water contaminants. As a result, today’s suppliers routinely monitor tap water for contaminants in parts per billion.
When the SDWA was amended in 1986, EPA was required to enact regulations on 83 compounds – some of which were natural and some manmade – that could potentially contaminate drinking water supplies. Congress also required the agency to study 25 new contaminant compounds every three years – a charge that proved too aggressive for the agency to handle.
The act was amended again in 1996, shifting EPA’s focus to high-risk microbial and chemical contaminants such as cryptosporidium, giardia, bacteria, viruses, arsenic and radon. Additionally, the agency’s long-term goals were revised. Now, every five years, EPA is required to identify a minimum of five contaminants that pose “the greatest public health concern” and consider whether to regulate them.
The 1996 SDWA also directed EPA to enhance consumer awareness regarding drinking water. As a result, beginning next year, all public utilities will be required to develop annual consumer confidence reports summarizing the characteristics of their communities’ water systems, locations of source water, quality of raw and treated water, contaminants present in the water and health risks posed by those contaminants. Conflict and balance Although local officials will be responsible for producing the annual consumer confidence reports, they are perhaps more concerned about the operational and financial implications of two regulations being finalized this November: the Interim Enhanced Surface Water Treatment Rule (IESWTR) and stage 1 of the Disinfectants/Disinfection By-products Rule. Because of their seemingly conflicting nature, they are, to date, the most complex rules to come out of the 1996 amendments.
The IESWTR requires large water utilities (those serving more than 10,000 people) to filter and disinfect water supplies to kill bacteria and other organisms that may be present. At the same time, the D/DBPR limits the amount of chemical by-products that can be formed during the disinfection process, thereby discouraging the overuse of disinfectants. Therefore, water utilities must find and maintain the delicate balance necessary to comply with both rules simultaneously.
A companion rule of the IESWTR is the Long-term Enhanced Surface Water Treatment Rule (LTESWTR), which will place filtration and disinfection requirements similar to those established in the interim rule on small water utilities (those serving fewer than 10,000 people). EPA is expected to finalize the LTESWTR by late 2000.
Together, the IESWTR and the LTESWTR revise and strengthen the 1989 Surface Water Treatment Rule. They focus on the removal of inert particles, microbial contaminants and specific disease-causing pathogens such as giardia and cryptosporidium.
For several years, cryptosporidium, which frequently is found in source water and is highly resistant to chlorination, has been EPA’s highest priority in microbial research. It was identified as an etiologic agent in waterborne disease outbreaks in 1993, when contaminated water caused more than 400,000 illnesses and more than 100 deaths in Milwaukee. (The intestinal disorder caused by cryptosporidium can be chronic or deadly for immuno-compromised persons.)
As a group, EPA’s new rules will tighten federal standards for water treatment. For example, enhancing and monitoring individual filter turbidity and performance will be essential for compliance with the IESWTR and the LTESWTR rules. Water service providers can expect the standard to call for combined filter effluent turbidity level criteria of 1 nephelometric turbidity unit (NTU) instantaneous and 0.3 NTU in at least 95 percent of the measurements taken each month.
Stage 1 (and a possible, future stage 2) of the D/DBPR will address the impact of disinfectants (e.g., chlorine, chloramine and chlorine dioxide) while minimizing the creation of disinfection by-products (e.g., total trihalomethanes (TTHMs), haloacetic acids, bromate and chlorite). Stage 1 will lower the TTHM maximum contaminant level from 100 mg/L to 80 mg/L and will apply to all utilities with staggered effective dates based on system size. (Unlike the current standard, which applies only to public water systems serving more than 10,000 people, stage 1 of the D/DBPR will apply to all systems. See the table on page 36 for a full implementation schedule.)
Inevitable changes Because many cities and counties use the same treatment processes they have used since the turn of the century, new regulations are likely to prompt significant, necessary changes to conventional water treatment systems. For example, the Enhanced Surface Water Treatment Rules, at the very least, will force local utilities to:
* optimize the use of treatment chemicals;
* enhance physical removal of particles;
* install better filters and better filter media; and
* in some cases, use advanced technologies such as membranes, which provide a physical barrier between microbial pathogens and the finished water.
Trying to anticipate the final provisions of the new rules, local officials are engaged in “a real crystal ball act,” says Brian Ramaley, director of the Newport News (Va.) Waterworks and a negotiator for the Association of Metropolitan Water Agencies during the EPA rulemaking process. However, Ramaley foresees several inevitable conclusions, including lower standard levels for most disinfection by-products and stricter regulations for microbial contaminants such as cryptosporidium and giardia.
Newport News operates a regional water utility with two treatment facilities that serve 400,000 people in five jurisdictions. The system’s design capacity is 85 mgd, and its average daily output is 50 mgd. In anticipation of the IESWTR and the D/DBPR, local officials have reviewed the city’s water treatment processes and are converting the two plants to use ozone as their primary disinfection method.
Although one of the plants was renovated with conventional technology in 1988, the other has parts dating back to the early 1900s. The city will incur construction costs of $15 million for the conversion, but Ramaley justifies the expense by noting that the ozone system will allow Newport News to reduce disinfection by-products to stage 2 levels while also disinfecting for cryptosporidium.
Building and budget considerations As they are in Newport News, treatment plant updates are under way in Billings, Mont. The city’s water treatment plant, built in 1887, serves nearly 91,000 people with 24,000 connections. It has a design capacity of 50 mgd but records a 20 mgd average daily use with summer flows nearing 45 mgd.
Billings’ water source is the Yellowstone River, the largest free-flowing river in the country. The treatment plant experiences major swings in raw water quality. Also, like many utilities, the plant recycles its backwash water, which, during high pumpage, comes right back on the filters. Under those circumstances, if one of the utility’s 10 filters were lost, the system probably would fall out of compliance with the proposed new standards.
The plant is outdated and is unlikely to meet IESWTR’s turbidity requirement of 0.3 NTU 95 percent of the time, says Joe Steiner, environmental engineer for Billings’ Public Utilities Department. The city’s alternatives are to revamp the existing facility (which it has done numerous times in the plant’s history) or build a new plant at a projected cost of $35 million to $50 million.
Steiner says he is giving “strong consideration” to a new, more efficient facility, noting that it will be difficult to design such a plant without a clear definition of upcoming regulations. The city plans to make some improvements based on presumptions about the new rules; however, whether it stops with renovation or opts for new construction, it will attempt to design a plant with the flexibility to fit into any regulatory scheme that may be proposed. For that reason, Billings may incorporate membrane technology, which Steiner believes could meet all requirements of the proposed regulations.
For smaller utilities, the required changes may be greater and more threatening to a local budget, says Marlyn Rinta, operations superintendent for the Kingsbury General Improvement District in Stateline, Nev. He recommends that small utilities take advantage of grants and loans available from federal and state agencies to fund pipeline replacements, storage capacities and updated treatment processes that may be needed to meet future requirements.
The Kingsbury General Improvement District provides 2,400 service connections to the rural area on the California/Nevada border on south Lake Tahoe. Although the area’s population is less than 10,000, the utility’s water production varies from 0.8 mgd to 1.2 mgd in the winter, and it averages 2.3 mgd in the summer. Kingsbury also provides water for snow production at nearby Heavenly Valley ski resort.Until 1993, the utility had oper ated a pump station and used chlorination for water treatment. However, in response to the 1989 Surface Water Treatment Rule and subsequent regulations, the utility board considered two significant options: installing a new filtration plant or applying for a filtration avoidance waiver from the state to use ozone as a disinfectant without filtration.
Because of Lake Tahoe’s generally good water quality, the second option was selected, and Kingsbury implemented an ozonation-deozonation-chlorination process. The lake has minimal natural organic material, and no problems with disinfection by-products have been encountered during quarterly testing.
Assessments are in order The IESWTR and the D/DBPR will be finalized this November and must be adopted by individual states within 24 months. Implementation by water suppliers will be required in phases, based upon system size; larger utilities will be required to comply first, while smaller utilities are likely to face compliance deadlines before 2004.
The phased implementation gives utilities plenty of time to assess compliance strategies and review existing water treatment practices to determine which processes need to be modified. It also allows time to forecast the expenses associated with those improvements.
Local government expenses will not be limited to mechanical or technological changes. For instance, as systems become more automated and sophisticated, operators will require additional training and more specialized skills.
The implications of the new EPA regulations and their potential impact on cities and counties are explored in a variety of seminars for local officials. For additional information, contact the National Rural Water Association, Duncan, Okla., (405) 252-0629, and the American Water Works Association, Denver, (303) 794-7711.
Tim Chinn is vice president and national director for potable water for HDR Engineering, Austin, Texas.
People who live in large communities pay less for their water and wastewater services than residents of small and medium communities. That is one of the findings of the “1998 Water and Wastewater Survey,” conducted by Raftelis Environmental Consulting Group, Charlotte, N.C.
The survey indicated that, at all usage levels, median monthly water and wastewater charges are lower for communities with populations above 1 million than they are for any other size communities. (Water charges are responsible for most of the difference; wastewater charges are more equivalent in large and medium-sized communities.)
Additionally, the median monthly water bill for an “average” customer with 1,000 CF (7,480 gallons) of usage increased from $13.98 to $15.70 since 1996, when the last survey was conducted. Those numbers represent a 6.1 percent annual increase. The median monthly wastewater bill for an “average” customer increased from $16.97 to $17.57 over the last two years, up about 1.7 percent annually.
Since 1996, the number of communities using a uniform block rate structure for water service has risen 2 percent to 34 percent. The number using declining block (35 percent) and increasing block (31 percent) rate structures dropped by 1 percent each.
Survey results were compiled with responses from representatives of water, wastewater and stormwater systems in 156 U.S. cities and counties. For a complete copy of the survey, contact the company at 6100 Fairview Tower, Suite 615, Charlotte NC 28210; (704) 556-1936.
Memphis and Shelby counties in Tennessee are among 140 U.S. communities named “Groundwater Guardians” by The Groundwater Foundation. The Lincoln, Neb.-based organization supports grassroots efforts to protect groundwater and recognizes activities ranging from education programs to full implementation of wellhead protection plans and local land-use ordinances.
In Memphis and Shelby counties, 173 wells supply all of the drinking water to more than 872,000 residents. The counties have formed a Groundwater Guardian team consisting of one citizen, two business/agriculture representatives, two government representatives and one educator.
In the last three years, the team has spearheaded a variety of efforts to protect the area’s groundwater resources. The outcomes include:
* establishment of policies and procedures for water to protect Memphis Sands Aquifer. The policies led to the sampling of 450 quasi-public wells;
* adoption of a well survey program that located and classified wells where public water is available;
* institution of a well-monitoring program for Shelby County’s primary water source;
* implementation of education and training to ensure that board members are qualified to speak about the value of water resources and conservation efforts;
* establishment of non-residential development notification to provide warning about development proposals within the aquifer recharge area; and
* designation of a household hazardous waste collection day to alert citizens about the effects of that waste on the area’s groundwater.
The Groundwater Foundation names Groundwater Guardian communities based on their demonstration of participatory approaches to groundwater protection. For more information about the program, contact The Groundwater Foundation, PO Box 22558, Lincoln NE 68542, (402) 434-2740.
Niskayuna, N.Y., recently took the plunge in water tank maintenance when it broke away from conventional inspection methods and employed divers to inspect its water tanks. In addition to reducing service interruption, the divers provided photographic evidence of the tanks’ condition, thereby allowing the town to assess maintenance needs accurately.
Traditionally, tank inspection has required partially draining the selected tank and viewing the interior from an upper access hatch. As a result, the tank could be out of service for days. Tank diving, on the other hand, simplifies the assessment process, reducing inspection time to several hours.
Three water tanks (one elevated tank and two standpipe tanks), ranging in age from 17 to 31 years, provide drinking water for Niskayuna’s businesses and 19,000 citizens. Officials selected Conrady Consulting Services, Vero Beach, Fla., to perform structural, sanitary and coating inspections inside and outside each tank.
For the interior inspections, a qualified diver, equipped with a surface air supply and a lifeline, entered the water. He used a self-contained, underwater video camera that included a high-intensity video floodlight, as well as an auxiliary 12V quartz halogen spotlight and test equipment. To eliminate the possibility of bacterial contamination, the diver either was sprayed with a 200 ppm chlorine solution, or a small amount of powdered chlorine was added to the water prior to his entry.
During the inspection, the diver looked for sand and silt buildup, leaks, cracks, rusted welds, and signs of corrosion and coating breakdown. He discovered that Niskayuna’s youngest tanks were generally in good condition, although their protective coatings were nearing the end of their life expectancy. However, the oldest tank showed extensive pitting, particularly at the seams. The tanks’ exterior protective coatings were in various states of disrepair. Although the elevated tank still maintained a bond to its base coat, the older standpipes did not.
Based on mechanical testing and visual assessment, the consultant recommended that the town blast and repaint all of its tanks. Additionally, it recommended structural repairs such as:
* adding new shell manways to provide better access to the tanks;
* adding new roof vents to improve ventilation and minimize corrosion above the waterline;
* removing some interior rail and adding new safety railings around the roof hatches; and
* installing new filler pipes at the base of the tanks and adding ladder guards to reduce liability and help prevent climbing by thrill-seekers.
With its needs identified, the town moved ahead with the repairs, issuing an RFP that included the underwater photographs taken during the inspection. “When we sought bids, we made the color photographs of the tanks available to the contractors,” says Rich Pollock, Niskayuna’s water and sewer superintendent. “The result was that [bidders] knew exactly what they were getting into, so the bids were lower and more accurate.” Contracts were awarded to Erie Painting, Buffalo, N.Y., for the elevated tank and to Millstone Corp., Lyons Falls, N.Y., for the two standpipes.
As maintenance work got under way, the town determined that blasting and repainting the tanks’ exteriors was not feasible. Removing lead-based primer was too costly, and there was not enough time to complete the project before the summer’s peak demand set in. Consequently, the contractors power-washed and scrubbed the tanks with a bristle brush, then spot-cleaned with a power tool and primed bare steel areas. They then applied Corothan I (a coating system that includes zinc primer, a mastic intermediate coat and an aliphatic finish coat) from Sherwin Williams Industrial & Marine Coatings Group, Cleveland.
Inside the tanks, workers had to meet special confined-space requirements and regulatory standards for lead paint removal and disposal. They wore respirators and protective equipment, and, because of the seasonal heat, compact Venturi air conditioners were strapped to the workers’ belts and blew cool air through their hoods.
Interior blasting was performed with 8-ton bulk sandblasting pots and air pressure supplied by Ingersoll-Rand 750-cfm air compressors. Two layers of protective coating were applied at 5 mils each of dry film thickness, and an intermediate coat was applied at 3 mils on all welds, seams and abraded areas. To aid in measuring film thickness, sanitary blue was used for the primer coat, and sanitary white was used for the intermediate and finish coats.
As the repairs were completed, Niskayuna officials took final steps to protect the tanks below their water lines. Impressed current cathodic protection systems were installed, with mixed metal oxide anodes suspended in the tanks to prevent icing damage. Rectifiers attached to the anode wiring automatically adjust for changing water chemistry to prevent corrosion.