July 2007, Vol. 19, No.7

Could Copper-Containing Fabrics Soon Be Affecting Your Wastewater?

Soon, a whole line of fabric products impregnated with copper-based biocides could be available for use and sale to consumers nationwide in stores and over the Internet. Such widespread household use, some wastewater treatment plant representatives worry, could cause facilities to exceed their permit limits for copper if the metal leaches out during laundering.

Soon, a whole line of fabric products impregnated with copper-based biocides could be available for use and sale to consumers nationwide in stores and over the Internet. Such widespread household use, some wastewater treatment plant representatives worry, could cause facilities to exceed their permit limits for copper if the metal leaches out during laundering.

Socks were the first such product to hit the market just under a year ago, according to Jeffrey Gabbay, whose company, Cupron Inc. (Greensboro, N.C.), is one of the primary manufacturers. The copper oxide compound bound to the sock fibers offers “continuous antimicrobial ... protection for the useful lifetime of the product,” according to advertising on the company’s Web site. “When microbes such as bacteria and fungi that can cause stains, odors, or product deterioration come into contact with the product surface, Cupron’s protection penetrates the cell wall of the microbe and disrupts key cell functions so that the microbe cannot function, grow, or reproduce.”

Within the next 2 months, the company will be offering a full line of “no odor ever” terrycloth products, including towels, bathrobes, T-shirts, underwear, and sports clothing, Gabbay said. Homecare products, such as sheets and pillowcases, are expected to follow soon thereafter.

Concerned about the potential negative water quality effects of widespread residential use, treatment plants in California are calling on the U.S. Environmental Protection Agency (EPA) to require these and other products like them to be registered as pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). If the manufacturers had to submit a FIFRA registration application to EPA, the agency would determine whether and under what conditions the copper-containing fabrics could be used. Moreover, the companies would have to supply scientific data to show that the use of these products will not pose an unreasonable risk to people or the environment.

“We’ve worked very hard to reduce the sources of copper in wastewater influent,” said Chuck Weir, general manager of the East Bay Dischargers Authority (San Lorenzo, Calif.) and chair of Tri-TAC. Tri-TAC is a technical advisory committee that represents publicly owned treatment works (POTWs) and is jointly sponsored by the California Association of Sanitation Agencies (Sacramento), California Water Environment Association (Oakland), and League of California Cities (Sacramento).

“We’re very protective of the gains we’ve made, and we don’t want to see any backsliding to create other sources of copper that could create problems for us,” Weir explained.

Water Quality Concerns
Just how much copper these fabrics might leach out during wash cycles is unclear. “We don’t know,” said Phil Bobel, manager of environmental compliance for the City of Palo Alto, Calif., and past president of Tri-TAC. “That’s exactly the type of question we think EPA and state agencies ought to figure out before a product like that is registered.”

In a Feb. 14 letter to EPA’s Office of Pesticide Programs, Tri-TAC notes that “copper is highly toxic to aquatic life at low concentrations. Due to concerns about aquatic toxicity and the placing of strict copper effluent limits in discharge permits, POTWs have implemented pollution prevention programs to identify and reduce copper discharges to sanitary sewer systems,” which have reduced POTW influent and effluent copper concentrations.

The letter also requests that EPA, during the registration process, obtain data on the quantities of copper ions released when such fabrics are washed under ordinary washing conditions. “These data should be used to impose necessary restrictions to ensure that water quality standards are not exceeded,” the letter states.

Gabbay maintained that company tests have shown that leach rates are not an issue. “The protection offered by Cupron-based products will last as long as the products themselves, regardless of multiple hot water washings, abrasion, or bleach,” according to the company’s Web site. In fact, Gabbay noted, at the end of 100 wash tests, the fabrics “are still killing the bugs.” He acknowledged that “it’s probably the case that there is some leaching,” but pointed out that “we’re not a polluting agent, because we’re an insoluble salt,” and therefore not bioavailable.

When effluent limits are written for wastewater treatment plants, however, “copper is copper is copper,” Bobel said, noting that the standard test regulatory agencies require is for total copper. So “if a plant is regulated for total copper, it really doesn’t matter whether it’s dissolved or not,” he said.

Additionally, once copper goes into a wastewater treatment plant, it has the potential to be environmentally important, said Kelly Moran, president of TDC Environmental (San Mateo, Calif.), an environmental consulting firm. “Sewage is a complicated environment, and there are a lot of things in there that will cause copper that wasn’t necessarily soluble to dissolve,” she explained. “If it’s not dissolved when it comes out in the washwater, those particles are exposed to all kinds of things in sewage where it takes one to several days to get through the whole system.” This long contact period and large surface area provide an ideal environment for that kind of chemistry to occur, she added.

Consequently, Tri-TAC is calling on EPA and the California Department of Pesticide Regulation to conduct these types of assessments, perhaps limiting or banning the sale and use of copper-containing fabrics in California. Registration under FIFRA would ensure that the environmental effects of these products are more thoroughly reviewed before being sold to consumers, the February letter states.

Other Products Raising Concern
These copper-containing fabrics are the latest in a growing number of household products containing new ingredients that may end up in collection systems and negatively affect water quality, according to Tri-TAC.

“We’re seeing more and more examples of companies trying to put something into a fabric or device that will have this effect of killing bacteria, and we’re very nervous that products like these will result in pesticide releases during the [laundering] process,” Bobel said. For instance, triclosan is used as an antibacterial agent in a host of personal care products, such as soaps, deodorants, toothpastes, and mouthwashes. In another example, mattress liners and clothing are impregnated with permethrin to ward off fleas and ticks.

Last year, Tri-TAC and the National Association of Clean Water Agencies (Washington, D.C.) successfully petitioned EPA to review washing machines that release silver ions as a disinfectant. Advertisements by the manufacturer, Samsung Electronics (Seoul, South Korea), claimed that nanoscale silver particles released during the wash and rinse cycles achieve 99.9% sterilization of bacteria and leave behind a residual silver coating on clothing to keep it smelling fresh for up to 30 days.

EPA initially classified the machine as a “device,” meaning it was not subject to registration requirements under FIFRA. Concerns raised by states and the wastewater industry, however, caused EPA to re-evaluate the product and determine that the silver ions are indeed pesticides and, therefore, should be regulated, according to the agency.

EPA was reviewing the latest Tri-TAC letter as WE&T went to press. “We have worked with Tri-TAC in the past on water quality issues and understand their concerns,” said Enesta Jones, an agency spokeswoman. “We agree that there are parallels to Samsung and the silver ion electrode technology, and that product is undergoing the [FIFRA] registration process at this time.”

For more information, see the Feb. 14 letter via the link to “documents” at www.tritac.org.

— Kris Christen, WE&T


Water Quality Trading Moves Forward
Although the concept of water quality trading has been around for decades, only in the past few years has trading begun to gain more widespread acceptance as a viable option for addressing the nation’s water quality woes. As long as the cost to remove pollutants from point sources continues to far exceed the cost to reduce an equivalent amount of pollutants from nonpoint sources, water quality trading will hold promise. Many barriers — regulatory, technical, and economic — have prevented the adoption of trading on a large scale. Yet as the number and format of trading programs increase and diversify, trading’s prospects for effecting significant environmental benefits appear brighter than ever.

A decade ago, state regulators tended to view trading with uncertainty, said Mark Kieser, acting chair of the Environmental Trading Network — an information clearinghouse that focuses on water quality trading — and senior scientist at Kieser and Associates (Kalamazoo, Mich.). In the absence of direction from the U.S. Environmental Protection Agency (EPA), “few states had much enthusiasm” for trading, Kieser said. After EPA finalized its 2003 Water Quality Trading Policy, some states felt as though they had been “given the green light” to pursue trading on their own without much risk, he noted. Today, eight states have finalized trading policies or regulations, and another three are developing policies or regulations, said Ginny Kibler, an economist in EPA’s Office of Water. Moreover, trading programs have been conducted in 11 other states that do not have statewide trading frameworks, she said.

For a market-based approach such as trading to work, “regulatory drivers” must be present that essentially “force” trading to occur, said Brent Fewell, former deputy assistant administrator for EPA’s Office of Water. A number of these regulatory drivers, including the rapid growth of the total maximum daily load (TMDL) program and the development by states of numeric nutrient criteria, “will force more and more communities to look at trading as a flexible option to meeting water quality standards,” Fewell said. However, such programs can take many forms, from strictly regulated to more of a free-market approach.

Reducing Nitrogen to Long Island Sound
In 2001, EPA approved a TMDL submitted by Connecticut and New York to address water quality impairments in Long Island Sound resulting from excessive nitrogen loadings. Under the TMDL, the two states by 2014 collectively must reduce nitrogen loadings to the sound by 58.5%, compared to an established baseline. However, Connecticut’s wastewater treatment plants (WWTPs) must reduce their nitrogen loadings by 64%. To help meet this ambitious goal, Connecticut in 2002 established the Nitrogen Control Program, a trading plan involving 79 WWTPs. A general permit issued by the Connecticut Department of Environmental Protection (DEP) sets annual nitrogen limits for each treatment plant, as well as an aggregate annual limit expressed as equalized pounds per day.

The trading program is intended to provide an incentive to facilities to complete projects that reduce nitrogen loadings, because doing so enables them to sell credits earned by discharging less than their allotted amount of nitrogen. Meanwhile, WWTPs that choose to defer construction of such projects can remain in compliance by purchasing credits. Individual facilities monitor their performance, notifying DEP of the amount of nitrogen in their effluent. Using these data, DEP informs facilities once a year if they have credits to sell or to buy. All credits are bought from or sold to DEP, obviating the need for treatment plants to negotiate with each other. To allay concerns of participating facilities, DEP guarantees that all credits will be purchased. The price of a credit is set annually by DEP’s commissioner after considering the recommendation of a Nitrogen Credit Advisory Board. “It’s not a free-market system by any means,” said Paul Stacey, DEP’s director of Planning and Standards Division. However, he noted, it is a “very straightforward” approach that requires a minimal amount of resources for the state to oversee.

The trading program has accelerated the pace of nitrogen reduction among Connecticut’s WWTPs and at less expense than otherwise would have been required, Stacey said. “It has saved us quite a bit of money, as opposed to the old traditional command-and-control approach,” he said. During each of the first 3 years of the trading program, Connecticut’s WWTPs, in the aggregate, discharged less nitrogen than the general permit allowed.

However, the program exceeded the permit’s aggregate limit in 2005, largely because of weather conditions that adversely affected the ability of WWTPs to remove nitrogen. Yet funding constraints also played a role. A reduction in anticipated state funding for WWTP upgrades “slowed down our progress,” Stacey said. As a result, the biggest challenge facing the program is ensuring a “steady, adequate stream of funding,” he said. The WWTPs face the added challenge of having to maintain their nitrogen reductions even as the state’s population grows.

Given these pressures, Stacey conceded that Connecticut “may have some difficulty” meeting the TMDL’s requirements. If so, DEP may have to re-examine its options for ensuring compliance, he said. “It may be that trading will go away, and we’ll have to look at individual plant performance and go to the more traditional type of management,” he said. “Or maybe we’ll have to increase the incentive for plants to perform better.”

Taking the Tualitan’s Temperature
Although many states are grappling with how to limit the amount of nutrients entering their waterways, Oregon’s biggest concern involves the temperatures of its waterways, as excessive thermal loads harm salmon and other aquatic organisms. In 2001, the Oregon Department of Environmental Quality (DEQ) issued a TMDL for temperature in the Tualitan River, a major tributary of the Willamette River. Although inadequate shade along the Tualitan and its tributaries is responsible for most of the thermal load, the TMDL allocated most of the required reduction to Clean Water Services (CWS; Hillsboro, Ore.), a public utility that operates four WWTPs that discharge to the river.

As it assessed its options for reducing effluent temperatures, CWS realized that a trading program in which it paid farmers to plant vegetation along degraded streambanks could cost much less than a mechanical solution, said Charles Logue, director of regulatory affairs at CWS. For example, the most likely option — a refrigeration system for cooling WWTP effluent — would have cost an estimated $50 million to construct and $2 million annually to operate. Furthermore, such a system would reduce temperatures along only a limited stretch of the river. By contrast, restoring riparian vegetation along the river’s tributaries would improve temperatures throughout the river’s watershed and, in particular, the headwaters that provide critical salmon habitat.

Under a permit issued by DEQ in 2004, CWS works with the Tualitan Soil and Water Conservation District to identify farmers eligible to participate in the Conservation Reserve Enhancement Program, a land retirement program run by the U.S. Department of Agriculture (USDA). Under the permit, CWS receives credits for the shade provided by the plantings. Since the trading program’s inception, Logue said, CWS has spent approximately $7 million to pay for plantings along roughly 27 km (17 mi) of streams, half of the 56 km (35 mi) of plantings that it is required to finance.

CWS also receives credits for reducing thermal loads by releasing water from Scoggins Reservoir into a tributary of the Tualatin. Released at an average rate of 0.85 m³/s (30 ft³/s) during July, the reservoir’s colder water reduces temperatures in the Tualitan. Augmenting flows in this manner provides CWS with slightly more than half of the credits it needs annually. This arrangement afforded the utility a measure of “regulatory comfort” in the program’s early years, Logue said.

Addressing WWTP Concerns
Because WWTPs are subject to much greater regulation than the agricultural sector, some in the wastewater industry object to the idea of funding efforts to reduce nonpoint source pollution, asking why they should “have to pay somebody to do the right thing,” said Tim Williams, managing director of government affairs for the Water Environment Federation (WEF; Alexandria, Va.). While acknowledging the inequity, Williams noted that for some WWTPs, it may be in their own self interest to consider trading.

Issues of equity aside, other key concerns regarding trading between point and nonpoint sources involve quantifying and verifying reductions from nonpoint sources. “The whole area is fraught with a great deal of uncertainty,” said Cy Jones, senior technologist at CH2M Hill (Englewood, Colo.). Compounding the problem, the extent to which many conservation practices decrease nutrient loadings remains unclear. To address this uncertainty, regulators typically mandate trading ratios that ensure significantly more nonpoint source pollution is reduced, compared to the point source loadings to be offset. Although necessary, such ratios are “still pretty arbitrary,” Jones said.

Acknowledging that nonpoint source reductions cannot be measured precisely, trading programs typically will use empirical models developed by EPA or USDA to simplify the process, Kieser said. However, the agencies continue to seek ways to advance the science of quantifying load reductions. For example, USDA’s Natural Resources Conservation Service (NRCS) has contracted with Colorado State University (Fort Collins) to develop the Nitrogen Trading Tool, a Web-based application that will enable users to account for local soils, as well as climatic and agronomic conditions, said Carl Lucero, national leader for clean water at NRCS.

Using the tool, farmers will be able to determine accurately the amount of nitrogen that will be lost from fields under different agricultural practices. “Producers can use the tool to explore different agronomic scenarios and their associated nitrogen surpluses that they may want to trade in the marketplace,” Lucero said. A prototype of the tool is expected to undergo pilot-testing this summer.

In another effort to quantify environmental benefits associated with various conservation practices, NRCS is leading the Conservation Effects Assessment Project, a program that began in 2003 and includes 17 projects involving conservation practices that are closely monitored to ascertain their performance. As data from the projects become available, Lucero said, “we can begin to be more certain” about the effectiveness of specific conservation practices.

Such certainty, however, means little if a credit provider defaults on its commitment to reduce pollutant loadings. For WWTPs, liability is a key concern when deciding whether to trade with entities that pledge to generate credits by reducing nonpoint source pollution, Jones said. As holders of National Pollutant Discharge Elimination System permits, WWTPs could find themselves in violation of the Clean Water Act if anticipated credits do not materialize. One way to alleviate such concerns, Jones said, is for trading programs to maintain a “credit bank” from which point sources can purchase additional credits in the event that their original source of credits defaults.

Working With Farmers
Located in southwestern Ohio, the Great Miami River’s watershed is “dominated” by agriculture, said Dusty Hall, manager of program development for the Miami Conservancy District (MCD; Dayton, Ohio), a special district established by the State of Ohio to provide flood protection and improve water quality along the Great Miami River. This preponderance of agricultural activity affords many opportunities for trading to reduce nonpoint source pollution in the watershed. Relying on $1.2 million provided by seven WWTPs and a $900,000 grant from NRCS, MCD initiated the Great Miami River Watershed Water Quality Credit Trading Program in 2006.

The program uses “reverse auctions” to determine the most cost-effective means to reduce loadings of total nitrogen, total phosphorus, or both from nonpoint sources in the watershed, Hall said. After MCD requests proposals for projects, soil and water conservation districts work with farmers to submit plans outlining the amount of nutrients to be reduced and the price per pound. These reductions are quantified using a spreadsheet developed by the Ohio Department of Natural Resources. Based on recommendations from MCD, an advisory board selects projects to receive funding. Credits generated by the program are allotted among the seven participating WWTPs on the basis of treatment plant size.

After two rounds of soliciting bids, MCD has approved 34 projects that are expected to reduce phosphorus and nitrogen loadings by a combined total of 150,000 kg (330,000 lb), Hall said. At a total cost of $409,000, the projects achieve their reductions at an overall average cost of approximately $2.75/kg ($1.25/lb).

Benefiting the Bay
Pennsylvania finalized its trading policy at the end of 2006. Although intended to be a statewide program, the effort currently involves watersheds that drain to the Chesapeake Bay, said Ann Smith, program analyst with the Pennsylvania DEP. The voluntary program was developed to help Pennsylvania meet the goals specified in its Chesapeake Bay tributary strategy, a framework for reducing the amount of nutrients and sediment entering the bay from watersheds within the state. To meet the strategy’s goals, Pennsylvania must reduce its loadings of total nitrogen and total phosphorus by 26.2 million kg (57.7 million lb) and 1.3 million kg (2.86 million lb), respectively, between now and 2010. To this end, point and nonpoint sources have been allocated “cap loads” for the pollutants.

Pennsylvania’s trading program is designed to encourage third-party organizations to act as facilitators of trades, although Pennsylvania DEP must certify all credits, Smith said. The arrangement already has begun to attract such facilitators, including Red Barn Trading Co. (Lancaster, Pa.). Because of its ties to an existing agricultural consulting and engineering company, Red Barn Trading has approximately 600 agricultural clients in Pennsylvania with which it can work to implement nutrient-reduction practices that can be converted into saleable credits, said Peter Hughes, Red Barn Trading’s president.

Red Barn Trading has had more than 350,000 credits certified by Pennsylvania DEP, Hughes said. After credits are sold, the money is used to pay mainly for engineered practices that will limit releases of nutrients, including barnyard improvements and structures for storing manure. Another practice involves transporting manure from the Chesapeake Bay watershed to other areas of the state with nutrient-deficient soils. As of early April, Red Barn Trading had conducted two trades, both involving developers needing to offset nutrient loads from new package wastewater treatment plants.

As third parties begin participating more in trading, the practice likely will become easier as the economics of trading become clearer, Kieser said. “There’s not a lot of market information out there yet,” he said. But as states develop regulations that entice more entities to enter trading, “we’re seeing a market infrastructure develop,” he said.

However, water quality trading’s potential has only just begun to be tapped, Jones said. “As growth occurs and the demand for credits increases, the financial resources are going to be there” to pay for projects, he said. Of course, such efforts may require new approaches to reducing pollutants. “We need to start being more imaginative,” Jones said.

— Jay Landers, WE&T