Chapter 13
Emerging Issues
The list of issues emerging within the water industry is constantly expanding. Such issues range from regulatory agendas with respect to individual or classes of contaminants to broader areas of regulatory concern that are the subject of more comprehensive programs and research. Regulatory oversight is a complex interaction of governing institutions and stakeholders with no one model prevailing. Accordingly, the outcome of many of these challenges is far from clear. At the same time, the governance of water resources with respect to human health and ecological considerations represents an enormous opportunity for investors as these concerns create a pipeline of business for companies engaged in all aspects of the water industry.
The focus on the U.S. Environmental Protection Agency (EPA), with respect to the regulation of emerging contaminants, provides a comprehensive list that is either paralleled in the other developed countries or will provide future guidance for developing countries as they advance beyond more basic water quality priorities. For example, microbial contaminants are a universal challenge due to the omnipresence of human pathogens, while perchlorate, an oxidant used in solid rocket propellant, is not likely to be present in the groundwater of sub-Saharan Africa. Given the extensive amount of research undertaken by the EPA, and the very vigorous advocacy climate that monitors this process in the United States, it is reasonable to adopt their water agendas as representative of the future. Emerging topics in the water industry include not only pure regulatory drivers but also economic drivers associated with compliance of existing regulations.
Unregulated Contaminants
It is instructive to peer into the future to determine which contaminants are of regulatory concern. Regulations drive business in not only the treatment sector as the best available technologies are adapted as a solution, or the analytical sector where measurement for occurrence and testing for compliance create additional applications, or the resource management sector where firms are paid to design systems that prevent or processes that remediate, but also, significantly, the water utility sector that must fund the capital expenditure to implement to regulation in the first place.
Contaminant Candidate List (CCL)
In the United States, the EPA is required to maintain a list of contaminants that are not currently subject to any proposed or promulgated national primary drinking water regulations, but that are known or anticipated to occur in public water systems, and which may require future regulation under the SDWA. They are divided into three categories: priorities for more research, priorities for more occurrence data, and priorities for regulation. The EPA is currently on their third version of the list (Contaminant Candidate List 3 or CCL 3), which includes 93 chemicals or chemical groups and 11 microbiological contaminants.
The key is to remember that inclusion on the CCL is still a potential and points to the regulatory risk inherent in the industry. For example, as will be seen, perchlorate has been the subject of exhaustive regulatory debate and, after several states adopted their own perchlorate standards, it was assumed that the EPA would as well. Now the EPA has said that a national standard for perchlorate may never be promulgated. It has been some time since regulatory risk has been a factor for water stocks.
A table of the microbial contaminant candidates and a table of the CCL 3 candidates can be found in Appendix A:Water Contaminants.
Case Study 1: Perchlorate
Perchlorate, a strong oxidant used as an ingredient in solid rocket fuel and in the manufacture of munitions, automotive air bags, and batteries, is showing up in a growing number of the nation’s drinking water supplies. Although little research has been conducted on the effect of long-term, low-level exposure to perchlorate, the EPA has included it on the CCL and considers it to be a probable human carcinogen. While the treatment of wastewater containing perchlorate is more established compared to drinking water, there is a rapidly growing need to address the treatment methods for removing perchlorate from drinking water.The perchlorate saga is a case study in the market-driving capability of regulations, this time to the downside. It seemed so probable that a national drinking water standard would emerge that it became the primary attraction for the Basin Water, Inc. initial public offering.
The Science Behind the Regulation. Perchlorate (ClO4-) is the most highly oxidized form of chlorine and originates from the dissolution of ammonium, potassium, magnesium, or sodium salts. Perchlorate is an oxidizing anion, but in dilute aqueous solution is very stable and inert and can persist for many decades under typical groundwater and surface water conditions.An important characteristic of perchlorate is its high aqueous solubility, which makes it exceedingly mobile in water. Perchlorate can migrate in subsurface systems substantial distances from the original site of contamination. This contributes to the difficulty in removing low quantities with conventional treatment processes.
Perchlorate is both a naturally occurring and man-made chemical. A major source of perchlorate contamination in the United States is associated with the manufacture of ammonium perchlorate for use as the oxidizer component and primary ingredient in solid propellant for rockets, missiles, and fireworks. Because of its limited shelf life, it must be periodically washed out of missiles and rockets and replaced with a fresh supply. Thus, large volumes of the compound have been disposed of over time.
Perchlorate salts are also used in the manufacture of munitions, automotive air bags, matches, and batteries. Other uses of perchlorate salts include their use in nuclear reactors and electronic tubes, as additives in lubricating oils, in tanning and finishing leather, as a mordant for fabrics and dyes, in electroplating, in aluminum refining, and in the production of paints and enamels. Chemical fertilizer also has been reported to be a potential source of perchlorate contamination. It is because of the diversity in the industrial use of perchlorate that there is serious concern that the occurrence of the chemical will grow now that detection technology has substantially improved.
Wastes from the manufacture and improper disposal of perchlorate-containing chemicals are increasingly being discovered in soil and water. Perchlorate has been detected in water supplies in at least 20 states. Those states most affected by perchlorate occurrence are western states such as California, Nevada, and Utah, where facilities that have manufactured or tested rocket fuels are located. In the western United States, perchlorate is estimated to affect the drinking water of more than 23 million people. In California alone, perchlorate has been detected in 284 drinking water sources. All told, there are 44 states that have confirmed perchlorate manufacturers or users based on EPA information request responses. The possibility of widespread occurrence of perchlorate contamination raises obvious concerns over the effects on human health.
Perchlorate interferes with iodide uptake into the thyroid gland. Because iodide is an essential component of thyroid hormones, perchlorate disrupts how the thyroid functions (i.e., is considered an endocrine disruptor). In adults, the thyroid helps to regulate metabolism. In children, the thyroid plays a major role in proper development in addition to metabolism. Impairment of thyroid function in expectant mothers may impact the fetus and newborn and result in effects including changes in behavior, delayed development, and decreased learning capability.
Changes in thyroid hormone levels may also result in thyroid gland tumors. The EPA’s draft analysis of perchlorate toxicity states that perchlorate’s disruption of iodide uptake is the key event leading to changes in development or tumor formation. The EPA concluded that the potential human health risks of perchlorate exposures include effects on the developing nervous system and thyroid tumors.
The EPA has not issued a health advisory for perchlorate or categorized it as a priority chemical for regulation. However, because of extensive occurrence data, California has moved to regulate the contaminant. In September 2002, California established the country’s first drinking water standard for perchlorate. California currently has an action level for perchlorate at 6 parts per billion (ppb) and has mandated that utilities monitor for its presence. Below 6 ppb, perchlorate is not thought to pose a health risk to humans. Massachusetts has set the standard at a more restrictive 2 ppb.
The EPA’s draft assessment includes a reference dose (RfD) that is intended to be protective for human health risks.The RfD is defined as an estimate, with uncertainty spanning perhaps an order of magnitude, of a daily exposure to the human population that is likely to be without appreciable risk of adverse effects over a lifetime. As with any EPA draft assessment document containing a quantitative risk value, that risk value is also draft and does not represent policy.Thus, the draft RfD for perchlorate of 1 µg/Lis still undergoing science review and deliberations both by the external scientific community and within the EPA.
Treatment methods for removing low levels of perchlorate from drinking water are also under considerable investigation. Perchlorate is known to resist most conventional treatment processes. Abiotic methods, such as biological treatment and ion (anion) exchange systems, are among the technologies that are being used, with additional treatment technologies under development. Because of the ongoing research efforts on the part of the EPA, there is as yet no best available technology (BAT) designated. Most of the research efforts employ biological treatment methods or ion (anion) exchange technology, although reverse osmosis (RO), nanofiltration (NF), and chemical reduction are being investigated. All ion-exchange processes produce a concentrated perchlorate solution, which must be disposed of or further treated.
Biologically catalyzed perchlorate reduction is also a promising treatment alternative for the removal of perchlorate. Although biologically based treatment of perchlorate-contaminated wastewater has been practiced since the 1970s, biological perchlorate removal technologies have only recently been applied to drinking water. Biologically active carbon (BAC) filtration, which destroys the perchlorate molecule and converts it to chloride, is one approach.
Biotreatment holds a great deal of potential due to the chemical properties of perchlorate. Because the chlorine atom within the perchlorate molecule is in its highest oxidation state, the reduction of perchlorate is highly thermodynamically favorable. Since perchlorate is a strong oxidant (i.e., accepts electrons readily), it provides a large amount of energy to microorganisms as an electron acceptor. Thus, in biologically active carbon, greater reduction of perchlorate is achieved. Because perchlorate is displaced by other ions in water that are more strongly attached to straight granular activated carbon (GAC), GAC filtration has not been shown to be an effective means of remediating perchlorate-contaminated water.
Savvy investors will see that treatment technologies for the removal of perchlorate from drinking water supplies is likely to be a niche growth opportunity within the water industry. But with the EPA’s decision not to establish a federal drinking water safety standard for the contaminant, investors also see a good example of the regulatory risk that can, albeit not too frequently, limit a market application. Specifically, a company like Basin Water was very dependent on the promulgation of a federal standard for perchlorate levels in drinking water. It now remains to be seen just how many states will act on their own.This is the purpose behind the several case studies: to impart an appreciation for the impact that regulation, or the lack thereof, has on investments in water.
Case Study 2: Methyl Tertiary Butyl Ether
Like perchlorate, methyl tertiary butyl ether (MTBE) is not a regulated contaminant under the Safe Drinking Water Act. However, since the EPA considers it to be a possible human carcinogen, MTBE is included on the CCL for further evaluation to determine whether or not regulation with a National Primary Drinking Water Regulation is necessary. All large community water systems are required to monitor for MTBE, and the EPA has issued an MTBE health advisory (based on tastes and odors) for drinking water at 20 µg/L (20 ppb or 0.02 ppm).
Made from methanol and a by-product of the oil-refining process, MTBE is added to gasoline to promote complete burning and to reduce emissions of carbon monoxide and organic combustion products, and it is showing up in ground and surface water all over the United States. MTBE is a synthetic compound that was first used in the late 1970s as a replacement for lead to boost octane. In 1990, in response to concerns over air pollution, Congress amended the Clean Air Act (CAA) to require the use of fuels that add oxygen to gasoline. In 1992, the Oxygenated Fuel program was initiated by the EPA to meet these requirements. The program required 2.7 percent oxygen by weight in gasoline in certain metropolitan areas during the winter months. The Reformulated Gasoline (RFG) program, initiated in 1995 also in response to CAA requirements, requires 2 percent oxygen by weight year-round in areas of the United States where air quality standards are exceeded.
MTBE was favored over other potential oxygenates because of its low cost, ease of production, and favorable blending characteristics with conventional gasoline. What was originally thought to be good for air quality has become a curse for water quality. Evidence of the detrimental effects of MTBE on drinking water supplies is mounting rapidly.
As a result, state regulatory agencies are increasingly mandating that MTBE contamination be addressed. California has enacted four bills relating to MTBE and has now adopted the primary contaminant level of 35 µg/L. Dallas imposed its toughest water use restrictions in nearly 50 years after a pipeline rupture spilled 600,000 gallons of gasoline reformulated with MTBE at a site that drains into a key drinking water reservoir. Numerous other states have set regulatory guidelines or standards for MTBE. New Jersey also has a drinking water maximum contamination level standard of 70 µg/L.The concerns are justified.
MTBE is especially problematic because it has a low taste and odor threshold, tends to migrate in subsurface systems much faster than other constituents of gasoline, and is difficult to remove from water at low concentrations via conventional treatment processes. MTBE, like other ethers, is hydrophilic, meaning it has a chemical attraction to water molecules. In fact, it is 30 times more soluble in water than other compounds of gasoline. Once MTBE is in groundwater systems, its high aqueous solubility makes it a fairly mobile contaminant. In addition, MTBE partitions weakly to soil and resists natural degradation. As a result of these factors, MTBE contamination spreads farther and faster in groundwater than other gasoline components.
The main sources of MTBE in groundwater supplies are leaking underground storage tanks and pipelines, spills, contaminated sites, and MTBE manufacturing and storage facilities. The primary sources of MTBE in urban surface water supplies are releases from gasoline-powered recreational watercraft and atmospheric deposition through precipitation of industrial or auto emissions. Stormwater contaminated with MTBE from gasoline leaks and spills also contributes to groundwater and surface water pollution.
Water industry officials generally support the EPA’s position but emphasize that existing contamination must also be addressed. According to the American Water Works Association (AWWA), communities around the nation face $1 billion in potential MTBE cleanup costs, yet no federal funds have been allocated to pay for it, nor has a best available technology been identified to deal with the problem. To this end, the EPA has assembled a work group to conduct field evaluations of technologies and processes to treat drinking water and groundwater contaminated with MTBE. Compared with other components of gasoline, MTBE is more difficult to remove from contaminated water. There are several treatment technologies that have been advanced for the removal of MTBE.
The more commonly considered strategies include air stripping, advanced oxidation processes (e.g., UV photooxidation or chemical oxidation such as ozone hydrogen peroxide), biological filtration, and adsorption with activated carbon or other sorbents. Because of MTBE’s relative inability to partition to the vapor phase, air stripping is less effective for MTBE removal than for other volatile organic chemicals usually encountered in contaminated groundwater. Advanced oxidation processes can be effective for destroying MTBE, although the concurrent formation of bromate from ozone or ozone hydrogen peroxide treatment may be a concern for some water supplies. Application of biological filtration following oxidation can reduce the concentrations of oxidation by-products. Removal via activated carbon adsorption is typically not cost effective for MBTE, but other sorbents are being examined for their efficacy and cost effectiveness. These findings support the consensus view within the water industry that typical water treatment processes designed for removal of other organic chemicals are not adequate for MTBE removal.
Other approaches that are being examined include application of traditional processes in series, optimization of existing treatment systems, and use of novel sorbents. Calgon Carbon, for example, has introduced Filtrasorb, an activated carbon product that is used in combination with the company’s adsorption systems and is specifically designed to remove MTBE from water. Groundwater remediation has been achieved by air stripping within specially designed density-driven convection wells. And pilot-scale compost-based biofilters have been developed with the ability to degrade MTBE. The bottom line is that there is not yet a clear consensus on a cost-effective solution for the removal of MTBE.
The United States produces, distributes, and consumes extensive quantities of gasoline, much of which contains MTBE. It is the third most produced organic chemical in the country.The concern is that we have only seen the tip of the iceberg with respect to MTBE contamination. A substantial amount of research is therefore being conducted on issues related to MTBE health risks, effects on air quality, environmental occurrence, fate and transport, site remediation, and water treatment technologies. As the research mounts, it is evident that the cleanup of MTBE will be an emerging niche within the water treatment business.
Case Study 3: Arsenic
After a lawful limit of 50 ppb for nearly half a century, and considerable debate, the EPA lowered the level for arsenic to 10 ppb in 2006. In a classic example of the trade-off between the protection of public health and the cost of compliance, the science behind the debate prevailed, identifying the potential risks to human health. The prevalence of arsenic in the environment, and the potentially significant impact on numerous drinking water systems, ensures that arsenic removal will be a niche growth market for treatment technologies.
Arsenic is an extremely poisonous semimetallic element. It is both a naturally occurring substance and an industrial by-product. Arsenic ranks about 52nd in natural abundance among the elements in crustal rocks and can combine with other elements to form inorganic and organic arsenicals. It is primarily the inorganic forms that are present in water and are of greatest concern. Most arsenic enters water supplies from erosion of natural deposits in the Earth’s crust or from industrial and agricultural pollution. The weathering of rocks, burning of fossil fuels, volcanic activity, forest fires, and mining and smelting of ores also contribute to releases in the environment and can lead to contamination of groundwater.
Commercial arsenic has been used in the manufacture of glass and military poison gases, for the hardening of lead, and as a pesticide. The most common compound, chromated copper arsenate, makes up 90 percent of the industrial arsenic in the United States and is used to pressure-treat wood. Arsenical compounds are among the most widely distributed elements in the earth’s crust and in the biosphere.The presence of arsenic in drinking water is of global concern. In Bangladesh, for example, it is estimated that 25 million people are exposed to arsenic levels far above 10 ppb from millions of shallow wells tapping groundwater supplies.
1 In the United States, arsenic is found at high concentrations in western mining states.
The International Agency for Research on Cancer has classified inorganic arsenic compounds as demonstrating sufficient evidence of being skin and lung carcinogens in humans. Long-term exposure to even low concentrations of arsenic can lead to skin, bladder, lung, and prostrate cancer and may lead to kidney and liver cancer. Noncancerous effects include cardiovascular disease, diabetes, and anemia, as well as reproductive, developmental, immunological, and neurological effects. Studies indicate that arsenic disrupts the glucocorticoid system; that is, it is an endocrine disruptor. Furthermore, arsenic promotes the growth of tumors triggered by other carcinogens.
The Safe Drinking Water Act amendments require the EPA to set the maximum contaminant level for contaminants such as arsenic based on peer-reviewed health effects research, studies of treatment, analytical methods, occurrence, and cost-benefits. After delays in setting a standard, a number of groups grew concerned that the EPA was unnecessarily prolonging the process. Lawsuits by the Natural Resources Defense Council prompted the Clinton administration to propose a standard of 5 ppb in drinking water. After industry protests, it was set at 10 ppb, and three days before Clinton left office the 10 ppb standard was adopted.
The Bush administration, however, suspended that action, citing costs to local communities and questioning the scientific basis behind the new standard. According to an AWWA Research Foundation study, a 10-ppb standard would cost drinking water suppliers nationwide $600 million a year, with capital costs of $5 billion. While the compliance costs are admittedly going to be high, the report by the National Academy of Sciences stated that the EPA had greatly underestimated the risks to public health.
Christie Whitman, the EPA administrator from 2001 to 2003, asked the academy to study the health effects of establishing a standard of 3, 5, 10, or 20 ppb. At each level, the study found that the cancer risks were much higher than the EPA had estimated. The academy report stated that, even at 3 ppb, the risk of bladder and lung cancer from arsenic exposure is between 4 and 10 deaths per 10,000 people. The EPA’s maximum acceptable level of risk for the past two decades for all drinking water contaminants has been 1 death in 10,000. As a result of seemingly compelling scientific evidence, the Bush administration had no choice but to accept the tougher arsenic standard. On October 31, the EPA formally announced the new arsenic standard of 10 ppb in drinking water. Despite the delays (the initial rule was promulgated in January 2001), the compliance date for the new standard was January 23, 2006.
According to the AWWA, nearly 97 percent of the water systems affected by the rule are small systems that serve less than 10,000 people each. The EPA will provide technical assistance and training to the operators of these small systems in an effort to reduce their compliance costs. The agency will work with small communities to maximize grants and loans under current State Revolving Fund and Rural Utilities Service programs of the Department of Agriculture. The effectiveness of a given treatment process depends on the type of arsenic compound being removed and the oxidation state. Many technologies perform most effectively when treating arsenic in the form of arsenic(V). Arsenic(III) can be converted to arsenic(V) through preoxidation. Oxidants such as ferric chloride, potassium permanganate, ozone, and hydrogen peroxide are effective for this purpose. Several conventional processes are effective for the removal of arsenic, including coagulation with ferric sulfate or alum, lime softening, activated alumina/adsorption, and ion exchange. Other technologies that can potentially meet the lower arsenic standard include RO, NF, and electrodialysis reversal (EDR).
Coagulation and lime softening are not appropriate for most small systems because of the high cost and the need for trained operators. In addition, these methods alone may have difficulty in consistently meeting the lowered arsenic maximum contaminant level (MCL). Activated alumina can also be inefficient to the extent that adsorptive capacity is lost with each regeneration cycle. For systems with existing conventional treatment, implementation of enhanced coagulation may be a feasible option. Ion exchange can effectively remove arsenic and is recommended as a BAT for most small groundwater systems with low sulfate and total dissolved solids levels. Each of these methods suffers from the problems associated with concentrated waste streams and sludge disposal.
RO can provide removal efficiencies of greater than 95 percent when operating pressure is ideal. If RO is used by small systems in the western United States, 60 percent water recovery will necessitate an increased need for raw water. Water rejection in the RO process is an issue in water-scarce regions, and recovery leads to increased costs for arsenic removal. Although NF has slightly lower removal capability than RO, water recovery levels can be lower, thereby allowing for greater efficiency. When compared to RO and NF, EDR is not considered to be competitive with respect to costs and process efficiency.
Since it is anticipated that the new arsenic standard will disproportionately impact small systems, point-of-use (POU) technologies are considered a viable option for arsenic removal. For POU methods, the key is to clearly define the size of the community where cost alone would make it a preferable alternative. For systems without existing treatment or small systems, membrane technologies offer a versatile approach.There are a wide variety of companies that engage in arsenic removal technologies. Clearly, there is a substantial amount of research and development that must yet take place to demonstrate the relative cost effectiveness of new and existing arsenic removal methods. Until the results of numerous studies have been analyzed, it is difficult to predict a single best technology. Investors must be patient as the EPA continues its research efforts.
There is probably more information to support the arsenic rule than most regulations that have been adopted in the last 30 years. At the same time, some believe that the arsenic standard could be the most expensive drinking water regulation ever. It is this combination that creates a positive outlook for technologies that cost-effectively remove arsenic from drinking water. Given that arsenic contamination is a global problem, companies that provide solutions in this arena should experience increased demand for their products and services.
Biosolids Management: There’s Money in Sludge
The management of wastewater treatment by-products is a business that continues to undergo transition subject to a regulatory landscape that is fraught with peaks and valleys. The potential growth in biosolids management is fueled by the need for treatment and disposal of growing quantities of product and the fact that residuals can be a beneficial resource. At the same time, the commercial use of biosolids is hampered by a negative perception associated with sewage sludge that politicians and consumers are having a hard time getting around. On balance, while the growth rate may be modest by current market standards, the residuals management segment remains a viable growth component of the water industry.
Dispersion of biosolids at sea is no longer permitted, and there is pressure on dischargers to use land-based options other than landfills. The Water Environment Federation estimates that 36 percent of biosolids are recycled, 38 percent landfilled, 16 percent incinerated, and 10 percent disposed of in other surface methods. Concerns with leachate control is likely to continue to divert organics like biosolids away from surface landfill disposal, and changes in air emission standards limit the use of biosolids incineration. In short, the demand for higher-quality biosolids will greatly influence processing choices. The EPA estimates that 7.1 million tons of biosolids were generated in 2000 and that by 2010 the amount will have increased to 8.2 million tons.
The labels given to wastewater by-products are often confusing and sometimes misleading. The shift in nomenclature from “sewage sludge” to “biosolids” underlies the intention to encourage the beneficial use of certain classes of waste materials. The term biosolids appears in the preamble of the Part 503 regulations that govern residuals. Coined by the Water Environment Federation, this term refers to those solids produced by domestic wastewater treatment and septage that can be beneficially reused. Webster’s Collegiate Dictionary, Tenth Edition, defines biosolids as “solid organic matter recovered from a sewage treatment process and used, especially as fertilizer.” But the EPA, to be consistent with language used in the Clean Water Act (CWA), often uses the term sewage sludge for the same type of material.The key concept is that biosolids are derived through the treatment of sewage sludge to quality criteria levels.
The requirements of the Part 503 biosolids regulations are very extensive and complex, including sections on land application, surface disposal options, strategies to reduce pathogens and vector organisms, and incineration. Overall, the regulations seek to encourage the reuse of sewage sludge while protecting public health and the environment; that is, it is a risk-based rule. The rule sets national standards for pathogens and limits for 12 pollutants with potential for adverse effects on humans and the environment.
Spurred both by regulation and technological advances, the cost-effective treatment, disposition, and management of sewage sludge is a controversial yet growing business. It is clear that the mandate on sludge reuse and management is a priority in the EPA’s regulatory scheme. Because of a lack of outlets for the beneficial use of biosolids, the current investment opportunity is primarily one of equipment manufacturers and service providers. As advanced treatment technologies are utilized to generate high-quality biosolids, the industry will be able to tap into markets with greater commercial appeal.This eventuality favors the residual management companies that provide solutions to the entire spectrum of municipal needs.
Biotechnology
In addition to bioremediation, there are a number of possible uses of biotechnology in the water industry. While conventional water and wastewater treatment methods utilize a variety of biological processes, the potential lies in commercializing new and innovative technologies that develop as products or services. Biochemical products for the consumer market, bioindicators, on-site testing and cleanup applications, and waste minimization through biological technologies are examples of first-generation biotechnology applications in the environmental industry.
One of the more intriguing areas of bioenvironmental research is biosensors, which combines biotechnology with materials and electronics to produce sophisticated monitoring devices for detecting pollutants in water. The first generation of biosensors utilizes immunoassay technology. This new technique relies on an antibody that is developed to have a high degree of sensitivity to the target compound. In the environmental industry, immunoassay methods provide timely, cost effective, and accurate information on contamination levels of key pollutants. Strategic Diagnostics Inc. is a leader in the development of immunoassay-based test kits for environmental contaminants.
Regulation
The regulatory environment is critical to investors because it helps drive the allocation of resources within the water industry. A review of the regulatory trends, legal mandates, and the EPA’s docket reveal the direction of policy issues and identifies the industry segments that may benefit as the regulations are implemented. Drinking water regulations are intended to reduce the risk of adverse health effects from exposure to contaminants that may be present in tap water. Specifically, the EPA has the authority and obligation under the Safe Drinking Water Act (SDWA) to set a National Primary Drinking Water Regulation (NPDWR) for contaminants. The 1996 amendments to the SDWA mandated the establishment of a series of new drinking water regulations. Since then, the EPA has been actively developing, proposing, and finalizing a number of regulatory actions. These regulations largely determine the landscape of the water industry and the framework for the provision of drinking water.
Several NPDWR revisions are currently in progress under EPA rule-making procedures. The agency is proceeding with revision of the Total Coliform Rule (TCR), which is intended to address unintentional fecal contamination and monitoring. Related to the TCR is a consideration of regulations targeted at distribution systems.The TCR, however, does not address the possibility of deliberate biological contamination of source waters and distribution systems. A consideration of deliberate microbiological contamination will require rethinking of not only how indicator organisms are used to reveal microbiological contamination, but also reconsidering which organisms should be monitored and what analytical techniques should be used. This is one factor that supports growth in the use of diagnostic tools and analytical devices.
Another regulatory front, and an area of considerable debate, is the proposed rule-making regarding Total Maximum Daily Loads (TMDLs). Much of the current TMDL debate focuses on the CWA efforts to control point sources of pollutants. Municipalities are concerned that implementation of the TMDL program will translate into increased controls on point source pollution, leading to significant increases in resources needed to meet the federal mandate. Despite the fact that the Water Pollution Program Enhancement Act of 2000 authorizes financial resources for programs related to implementation of TMDLs, the AWWA believes that it is critically important to include nonpoint source controls in the regulatory scheme. The EPA, however, has indicated that this will not be addressed in the final TMDL rule. Much more debate on the TMDL program can be expected, given the high-stakes nature of the outcome.
The EPA has also released the proposed Ground Water Rule (GWR), which specifies the appropriate use of disinfection in groundwater and establishes multiple barriers to protect against bacteria and viruses in drinking water systems that use groundwater. The proposed rule is the first to extend protections to underground sources of drinking water and will apply to all 157,000 U.S. public water systems that use groundwater.The GWR was issued as a final regulation in late 2001. The GWR must be promulgated no later than the promulgation date for the Stage 2 Disinfectants/Disinfection By-products (D/DBP) rule.
Currently, only surface water systems and systems using groundwater under the direct influence of surface water are required to disinfect their water supplies. A monthly source-monitoring requirement is included for systems that are “sensitive” to microbial contamination or have contamination in their distribution systems. In addition, a compliance-monitoring requirement applies to all groundwater systems that notify states they disinfect in order to avoid source water monitoring, and to systems that disinfect as a corrective action. The proposed strategy of the GWR addresses risks through a multiple-barrier approach and will clearly benefit the disinfection and monitoring segments of the water industry.
As expected, the EPA proposed slashing the current arsenic standard from 50 µg/L ppb to 5 µg/L parts per million (ppm) to reduce public health risks. The significance of the current proposal is that this is the first time that a maximum contaminant level (MCL) has been set higher than a feasible level based on cost-benefit factors. The AWWA has recommended that the standard be set no lower than 10 µg/L.The proposed arsenic rule will impact many community water systems and provide additional protection to at least 22.5 million Americans. It is estimated that the lower arsenic standard will cost $1.5 billion annually. Water systems in western states and parts of the Midwest and New England that depend on underground sources of drinking water will be most affected by the proposal. The BAT for meeting the proposed standard includes ion exchange, activated alumina, RO, modified coagulation-filtration, modified lime softening, and EDR.
Another significant debate is swirling around the regulations for the balance of radionuclides (primarily alpha and beta emitters, radium, and uranium).The balance of radionuclides is an extremely complex regulation, due to the very nature of radiochemistry, and due to the different isotopes involved in the rule-making. Because of this complexity, and the difficulty in implementing the monitoring requirements, the costs associated with the regulation are expected to be significant. Other areas of regulatory activity include the implementation of aluminum standards, revisions to the lead and copper rule, and the chloroform maximum contaminant level goal (MCLG) (which is driven by the disinfection by-products rule). Each of these regulations requires advanced filtration technologies and/or alternatives to existing treatment methods.
Water utilities are giving particular attention to planning for compliance with the anticipated Stage 2 D/DBP rule and the associated Long-Term Enhanced Surface Water Treatment Rule (LTESWTR). Although the EPA is still developing a proposed rule, the Stage 2 Federal Advisory Committee Agreement contains enough detail for water systems to begin planning for their compliance with these rules. This would entail an evaluation of disinfection by-products data, identifying actions that could be taken to reduce DBPs, and evaluating alternative microbial treatment technologies.
While regulations are an important factor in generating demand for a particular process, technology, or capital investment, the reality is that compliance costs money. And given the usually substantial cost of these mandates, funding is often a concern. The Drinking Water State Revolving Funds (DWSRF) legislation is, therefore, of great interest to municipalities and firms supplying the water industry. Through DWSRF, public water systems can get assistance with financing the costs of infrastructure needed to achieve or maintain compliance with regulations. These funds can be used to develop and implement programs for capacity development and source water protection.
To date, Congress has provided $3.6 billion in funding for the DWSRF program. By the end of the 2002 fiscal year, the EPA expected that 2,100 loans will have been made and more than 450 DWSRF-FUNDED projects will have begun operating. To further address drinking water infrastructure needs, $825 million has been requested by the EPA for the DWSRF in the 2002 fiscal year budget. Despite the fact that appropriations are nowhere near what the water supply community would like to see, the DWSRF legislation continues to be a crucial mechanism by which technology is transferred to the marketplace. The bottom line is that this funding helps fuel demand in several segments of the water industry, namely, privatization initiatives, new treatment technologies, and infrastructure development.
Filtration and disinfection methods that deal effectively with microbial concerns are likely to receive increased attention. Monitoring (diagnostic and analytical) is also seen as a high-growth segment due to importance of cost-benefit analysis, information gathering, and compliance.
The draft proposal of the Stage 2 D/DBP rule contains an MCLG for chloroform, a by-product of chlorine disinfection, of 0.070 mg/L. This would be the first nonzero MCLG ever set for a carcinogenic contaminant. The draft requires a comprehensive program of identifying peak DBP levels over the entire distribution system and sets a time frame to comply with the current total trihalomethanes (TTHM) standards. The draft of the Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) seeks to enhance the existing level of protection against pathogens afforded by the interim rule. The preproposal draft requires most filtered and unfiltered surface water systems to monitor for Cryptosporidium for the first time and sets the stage for the use of ultraviolet (UV) disinfection.
While regulations are an important factor in generating demand for a particular process, technology, or capital investment, the reality is that compliance costs money. And given the usually substantial cost of these mandates, funding is often a concern. The DWSRF legislation is, therefore, of great interest to municipalities and firms supplying the water industry. Through DWSRF, public water systems can get assistance with financing the costs of infrastructure needed to achieve or maintain compliance with regulations. These funds can be used to develop and implement programs for capacity development and source water protection. Despite the fact that appropriations are nowhere near what the water supply community would like to see, the DWSRF legislation continues to be a crucial mechanism by which technology is transferred to the marketplace. The bottom line is that this funding helps fuel demand in several segments of the water industry, namely, privatization initiatives, security, new treatment technologies, and infrastructure development.
The BATs for complying with these regulations are a good way of anticipating treatment trends and the relative demand for competing technologies, equipment, and services. Filtration and alternative disinfection methods that deal effectively with microbial concerns are likely to receive increased attention. Monitoring (diagnostic and analytical instrumentation) is also seen as a high-growth segment due to the importance of cost-benefit analysis, information gathering, and compliance.
Regulating Nonpoint Sources of Water Contamination
In broad terms, the sources of water pollution can be categorized in two ways. One is contamination that originates from an identifiable point, for example, the end of a pipe or a channel. The other is nonpoint sources, which affect water quality in a more indirect and diffuse way, such as agricultural activity or urban runoff. With point sources of pollution firmly entrenched in the regulatory scheme, the EPA is stepping up its activity to address nonpoint sources—a challenge with significant water quality implications. Given this developing interest, the management of nonpoint sources of contamination is an emerging investment theme moving forward into the next decade of water quality protection.
It is estimated that as a result of the gains made in controlling point sources, nonpoint sources now compose over half of the waste load borne by the nation’s waters. In retrospect, the enormous environmental impact of nonpoint sources now appears to have clearly justified a more balanced regulatory policy. Historically, in contrast to the control of point sources, the EPA was given no specific authority to regulate nonpoint sources.This type of pollution was seen by Congress as a state responsibility and is a large part of the paucity of regulation regarding nonpoint pollution.
Nonpoint sources of contamination do not exhibit the same economic characteristics as point sources. That is, a particular source cannot always be isolated with some specific activity held accountable. Because of this, economics cannot govern as efficiently. While some market solutions have emerged, such as point/nonpoint trading formats, as a means of creating additional point source discharges, the regulation of nonpoint sources must be intensified. And this is the case as the EPA has promulgated an extensive array of regulatory mandates aimed at dealing with nonpoint sources of water pollution.
The EPA is developing a strategy for strengthening nonpoint source management and intends to dramatically pick up the pace in nonpoint source control and watershed management. The initial focus is on runoff. The EPA has adopted the approach of best management practices for the control of urban nonpoint stormwater runoff. Under the final rule, municipalities must ensure that new construction projects have proper stormwater management systems in place. Stormwater runoff is seen as the major contributor to nonpoint water contamination.
Stormwater is posing an increasing problem as runoff transports pollutants, such as sediment, fertilizers, pesticides, hydrocarbons, and other organic compounds and metals, such as lead, into water bodies. This has major ramifications for the degradation of coastal life zones and the eutrophication of freshwater bodies. In addition, gravity collection systems often overflow and backflow during storms. As a result, flow is only partially treated at the wastewater plant or is bypassed to the nearest stream or river. Increased volumes of runoff also negatively affect groundwater elevations and lessen the volume of water percolating through the soil, thereby lessening the dilution of contaminants entering groundwater. Overflows carry untreated pollutants into watercourses, and backflows can affect the homes of collection system customers.
The overflow and backflow occurrence is commonly ascribed to infiltration and inflow (I/I) and is a continuing problem despite newer construction techniques and system components (joint design, pipe material and installation, and manhole fabrication). An early response to the problem was to overdesign for peak storm I/I. As much as eight times normal dry-weather peak flow capacity was provided in the 1950s.Yet, after just a few years, sewers all too typically ran full during storm events. Because manhole lids were bolted down, pressurized sewers delivered much more flow to the plant than could be fully treated.
Still today, problems associated with stormwater runoff, sanitary sewer overflow, and combined sewer overflows are attacked in a rather haphazard fashion by operators and engineers. Collection mains and overflow outlets are often localized solutions that only treat the symptoms of the problem.The EPA is working with the wastewater industry to standardize sanitary sewer overflow control policy. The operators of wastewater treatment plants and collection systems are concerned about the way that discharge permits are applied to sanitary sewer overflows and that the requirements of the CWA are consistent with engineering realities and health and environmental risks.Their concerns are justified.
According to EPA reports,
2 which are used to establish infrastructure priorities, the United States needs nearly $140 billion over the next 20 years to meet wastewater treatment requirements alone. The three greatest components over the next 20 years were not surprising. They include nearly $45 billion for controlling combined sewer overflows, $44 billion for wastewater treatment in general, and $22 billion for new sewer construction. In addition, the EPA estimates $10 billion for upgrading existing wastewater collection systems, $9 billion for nonpoint source control, and $7 billion for controlling municipal stormwater.
From an investment point of view, the infrastructure challenge of controlling nonpoint sources of water contamination can be broken down into several components. There are the basic products used in wastewater and sewer systems like concrete and steel pipe and tunnels or high-density polyethylene. Also in this category are the appurtenances, such as valves, backflow devices, and pumping equipment, that are required in nonpoint control systems.
Another segment that will certainly grow in importance is technology—that is, the companies that provide technological advances in nonpoint source pollution control. Also of interest are the new technologies that are emerging in response to specific nonpoint problems such as stormwater and agricultural runoff. For instance, a pelletized compost medium that traps particulates, adsorbs organic chemicals, and can remove heavy metals has been patented. The filter medium is put into radial-flow filter cartridges that are inserted into precast vaults or custom-designed structures and placed, for example, underneath parking lots and next to highways.The technology is promising as a passive stormwater treatment method that goes beyond sedimentation and filtration and requires less land than conventional stormwater treatment methods.
Due to the magnitude and complexity of agricultural runoff, microfiltration systems are being designed specifically to remove nutrients, sediments, selenium, and pesticide residues. The application of sophisticated technologies in addressing nonpoint source pollution creates a substantial opportunity for filtration, microfiltration and separation companies.
Another segment that has applications to the nonpoint source theme is based on the need to monitor and measure the effectiveness and cost efficiency of any practice or system to meet the inevitable nonpoint regulations. Metering, real-time data collection, and monitoring programs will more effectively control nonpoint contamination in the future. Sewers can then be designed and operated with an optimal peak capacity rather than overdesigning as an approach to controlling peak flows.
For various institutional, economic, and regulatory reasons, nonpoint sources have not received the proper allocation of resources that is deserved, given the impact of this category on water quality. It is clear that uncontrolled nonpoint sources of water contamination must be addressed with the same vigor that point sources have been regulated to date. The EPA is committed to dealing with this area, starting initially with stormwater runoff, but the costs will be high. While the specifics of any regulation of nonpoint sources are a long way from being known, the nature of best management practices will certainly encompass structural modifications and technological advances in dealing with the problem.
Water Reuse
Despite an understandable lack of public acceptance toward drinking treated wastewater, the fact is that all water is eventually reused—the hydrologic cycle is a closed system. The notion of water reuse can take on a variety of applications, from groundwater recharge to industrial recycling to direct potable reuse. The common thread is economics; different uses and reuses can be addressed with differing water quality levels. It makes little sense to use water treated by RO, for instance, to flush toilets. It is the necessity of differentiating water supply needs that will inevitably govern the growth of water reuse.
While on a macro scale water has traditionally been thought of as a replenishable but depletable resource, the accumulated degradation of supplies and burgeoning demand has modified its economic status on a micro level. Because of the imbalance of supply and demand, and the lack of a workable structure to achieve local equilibrium, water reuse presents a mechanism to efficiently allocate water, that is, replenishing a depletable resource through “recycling.”
Water reuse generally refers to the use of wastewater following some level of treatment and is often analyzed in terms of an emergency water supply, a long-term solution to a local water shortage, or a fringe benefit to water pollution abatement. Water reuse can be inadvertent, indirect, or direct. Inadvertent reuse of water results when water is withdrawn, used, treated, and returned to the environment without specific plans for further withdrawals and use, which nevertheless occur. Such use patterns occur along many rivers and, in fact, are accepted as a common and necessary procedure for obtaining a water supply. That is, dilution is the solution to pollution.
Indirect water reuse is a planned endeavor, one example of which is using reclaimed wastewater to recharge groundwater supplies. Artificial recharge of depleted aquifers using treated municipal wastewater is increasingly common. Direct water reuse refers to treated water that is piped directly to the next user. For now, the “consumer” is industry or agricultural activity in most cases. But indirect and even direct potable reuse remain viable options.
As competition for groundwater increases, particularly in the western United States, so does the need for innovative ways to manage water efficiently. The National Research Council’s Committee on Groundwater Recharge recommends strategies for using artificial recharge in areas where supplies have been depleted. It has not been shown that water recovered from recharged aquifers poses any greater health risks than currently acceptable potable water supplies. However, it is stressed that due to uncertainties and possible health risks, these sources should be considered for potable purposes only when better-quality water is unavailable.
One growth area within the reuse category, therefore, is pretreatment. Wastewater must receive a sufficiently high degree of pretreatment prior to recharge to minimize degradation of groundwater quality and the need for posttreatment at the point of recovery. As the regulations that govern effluent discharged to receiving waters become increasingly stringent, industry—as well as municipalities—has an economic incentive to reuse or recycle process water and wastewater.
Nonpotable reuse is well established in some areas of the United States and is drawing attention in other areas. Since there is not a general regulatory framework for reclaimed water at the federal level, states are responsible for setting the criteria for nonpotable uses such as irrigation and recreation. The question under debate is whether these criteria are adequate to protect public health from chemical constituents and microbial pathogens, including viruses and parasites such as Giardia and Cryptosporidium.
As an indication of the current interest in this topic, the American Water Works Association and the Water Environment Federation recently sponsored Water Reuse 2001. The conference agenda addressed the latest developments in water reuse technology and applications. While irrigation and industrial, urban, and indirect nonpotable reuse are developing applications for reclaimed water, the challenge is public acceptance and protection in the application of reclaimed water to potable uses. Critical to this evolution, and a major opportunity, are disinfection and membrane technologies that will drive the expansion of water reclamation.
Relative to drinking water regulations, standards were developed piecemeal to address problems in traditional water sources.They do not fully address the problems of converting reclaimed water into drinking water in the areas of virus control and organic matter. As such, significant progress must be made in legislating additional criteria for controlling contaminants in the water reuse process. While surface water augmentation with reclaimed water is being practiced under strict state guidelines, an interim step in the evolution of water reuse is the dual distribution system.
California has taken a leading position on the regulation of water reuse and requires filtered, disinfected water for such areas of concern as swimming and irrigating vegetables. In the Irvine area, reclaimed water has been used for 20 years to irrigate crops and lawns. Now, officials want to expand the use of reclaimed water. Dual water systems, which distribute both potable and reclaimed grades of water to the same service area, are becoming prevalent, particularly in California and Florida.The main disadvantage of building and operating a dual system is economic. In San Diego it was found that unit cost tends to be high for a fairly limited distribution system. As the dual system is expanded, the optimum unit cost is reached. Beyond this optimum range, the unit cost rises and the project’s cost effectiveness may be lost.
An advantage of dual systems is that the suppliers that operate the drinking water distribution system can handle the reclaimed water using the same technology. As more systems explore alternative disinfection and advanced filtration methodologies, the opportunity for institutionalizing water reclamation becomes more compelling. In addition, nonmonetary factors such as reliability and environmental effects will increasingly influence the decision.
Two of the largest reclamation systems are in Irvine, California, and St. Petersburg, Florida. The fact that these systems were built without subsidy indicates that they are economical. In new developments, both lines are installed at once, and buildings are plumbed for both grades of water. The costs are low compared with the costs of retrofitting older areas. Thus, as time goes on, dual systems will increase in potential.
It is clear that water reuse is an economic proposition that is inevitable in the future of the provision of water. As a general category, it has yet to fully emerge as an industry segment of the water industry capable of defined investing. Nonetheless, it has broad implications for existing segments such as privatization, distribution systems, infrastructure components, disinfection technologies, and membrane utilization. And as the public accepts reclaimed water as part of the recycling ethic, reuse will secure a permanent position in the scheme of efficiently providing water for all consumptive uses.
Water Conservation
One of the major platforms of the water supply industry in recent times is the notion of water conservation. Having been denounced for the expansion and development of environmentally sensitive and costly water supplies, the only other option in the equilibrium equation available to water purveyors is to reduce demand. The concept has caught on among water providers and the crescendo increases with every annual convention that pays homage to its political might. With such a forceful movement under way in the water industry, the opportunist must ask the logical economic question, namely, who will benefit from the conservation of water?
The conservation issue with respect to water resources is an interesting combination of the characteristics peculiar to the water industry. Why conserve at all? Although only 0.3 percent of the earth’s total water supply is fresh water available for human consumption, the absolute amount, some 1 million cubic miles, is very large indeed. Therefore, the argument for water conservation is generally not based on a limited global supply, as it has been with other natural resources. The major reason for water conservation is not its scarcity but rather the environmental costs of supplying it.
An important distinction under the notion of conservation is the difference between involuntary and voluntary conservation. The former is more accurately called rationing and is dictated by municipal authorities, much like the gasoline rationing of the late 1970s. The notion of voluntary conservation is to be distinguished on the basis of behavioral change as a response to institutional or structural occurrences, that is, conservation motivated by economic forces. This is the type of conservation significant to the water industry, both because of the implications of reduced demand and the impetus for new participants to enter the market.
One way to view the investment opportunities in water conservation is by analyzing the various conservation measures. For instance, there is significant investment potential in metering. Water metering is a structural measure that is critical to reducing water demands because users pay according to the actual amount of water they use.Water meters are thought to be commonplace, but some major cities in the United States remain partially unmetered, and as a percentage of taps, unmetered accounts are still large. As imagined, the international potential is huge. Water meter manufacturers such as Badger Meter, Inc. and meter service providers such as Itron, Inc. are direct ways to play the conservation theme. Other companies such as Health Consultants Inc. provide water accountability services such as meter testing and leak detection.
Other conservation measures involve water-saving devices. About 63 percent of residential water use occurs indoors. The bathroom alone accounts for approximately 75 percent of indoor use, so it is an ideal target for municipal water conservation measures. Low-flush and ultra-low-flush toilets use 19 to 28 percent less water than conventional toilets (defined as = 3.5 gallons/flush). The ability to save water by reducing the amount of water consumed in toilets is validated by the myriad of low-flush devices. There is Mini-Flush, Frugal Flush, and FlushSaver, to name a few. But the best way to invest in water-saving devices is through the large, national plumbing fixture manufacturers such as Eljer, Inc. Improved irrigation technology, particularly in agriculture, is another good way to invest in water conservation. Valmont Industries and Lindsay Manufacturing hold over two thirds of the U.S. irrigation equipment market for center pivot and lateral move systems, which address efficiency issues in agricultural water usage.
The basis for residential water conservation is not only the physical amount of water involved but the large—and growing—environmental costs related to its procurement, transmission, treatment, and distribution. While agricultural and industrial water consumption obviously entails environmental costs, there are relevant differences that are addressed within other components of the water industry. Agriculture, which accounts for 85 percent of consumed water, is affected by the dynamics of groundwater usage with little distribution required, and industrial consumption is subject to internal costs that are increasingly captured in the production process. This is not to minimize conservation in other than the residential context but to emphasize that the main reason for developing new water sources is demand from municipal systems, the largest component of which is residential. Conservation would not be a viable concern unless reduced demand had a leveraged impact on costs, both economic and environmental.
The evolution of water conservation from primarily an emergency measure to mitigate short-term water shortages to its new status as a long-term policy concern has challenged the traditional engineering approach to water supply problems. To be institutionalized, water conservation must impact the economic decisions of consumers using water. As such, pricing can be a powerful measure in influencing the amount and timing of water usage. Judging by the political furor that often accompanies water utility pricing policy, it is often not clear just how economic principles are to be applied to water resource problems. Economic principles of resource allocation dictate that when costs are incurred in the acquisition and transport of water supplies to customers, the principle of equimarginal value in use is combined with the principle of marginal cost pricing.
Marginal cost pricing is widely touted in the water supply industry, but few water utilities actually incorporate it into their rate schedules. Concerns over revenue stability and equity often prevail over the logic of charging for the true cost of service. It is precisely because of practical considerations, such as location, use patterns, type of service, and so on, that the marginal costs of serving all customers will not be the same. The consumption characteristics of residential customers indicate that the real price of providing water must increase to reflect the true costs associated with the particular patterns of demand imposed on the system. It is this concept that provides much of the impetus for change in water pricing as a conservation measure.
While the regulatory setting indicates that the real cost of providing water will rise, the conservation trend virtually guarantees it. The use of pricing in particular has a dramatic effect because it links the supply and demand for water. As this occurs, the alternatives to the way we traditionally obtain water—from the tap—become attractive. So, in addition to nonprice considerations (quality concerns) that are currently driving the market for tap-water substitutes, price will reinforce the shift in demand. The answer, then, to the original question as to who will benefit from the conservation of water is that POU treatment technology will gain. The reason for the reluctance of the water supply industry to implement exactly what they espouse then becomes clear.
Nanotechnology
Nanotechnology, at least relative to scale, is nothing new to the water industry. NF is one in a range of filtration methods. In fact, NF is an order of magnitude above where more advanced separation levels occur. By definition, reverse osmosis (also referred to as hyperfiltration) takes place at the nanolevel, dealing with separation in the ionic range, which is much smaller than the molecular range of NF. The interest of nanotechnology to the water industry, however, is more premised on the various applications of nanomaterials than it is the basic filtration of contaminants at the nanolevel. But as important as nanotechnology is to emerging markets in water, the potential market for removing nanoparticles from water represents an enormous, yet still unknown, aspect of treatment. The nanowastewater market is likely to be a huge growth subsector of wastewater treatment, rising in parallel with the widespread commercialization of nanotechnologies.
Algal Toxins
Stormwater runoff, nonpoint source pollution, and wastewater discharge are each distinct water quality challenges. Yet all share a common impact on receiving waters that is becoming a water quality issue in its own right; namely, the increasing occurrence of algae. Combined with a substantial increase in the use of surface water, eutrophication of water supplies presents a growing problem for municipalities. Increased nutrient loading from urban runoff, farming, and improperly treated wastewater has raised the incidence of algal blooms. Toxins produced by algae can have adverse health effects on wildlife, aquatic biota, and humans and is becoming an increasing concern for regulators and treatment plant operators.
The frequency and duration of harmful algal blooms have shown a dramatic increase in recent years. Most occurrences of cyanobacterial (blue-green algae) toxins are caused by nutrient overenrichment or eutrophication. Eutrophication is a process whereby water bodies, such as lakes, estuaries, or slow-moving streams, receive nutrients that stimulate excessive plant growth such as algae. Nutrients can come from many sources, such as fertilizers applied to agricultural lands, golf courses, and lawns, the erosion of soil-containing nutrients, and wastewater treatment plant discharges. The loading is often magnified by decreased water flow caused by improper watershed management or drought. And growing populations suggest that more algae-prone surface waters will be used to meet future demands.
The EPA’s CCL includes freshwater algae and their toxins as one of the microbial contaminants selected for regulatory consideration, but it does not specify which toxins should be targeted. In May 2001 a panel of scientists was convened to assist in identifying a target list of algal toxins that are likely to pose a health risk in drinking water.The EPA is reviewing the list and will select the final toxins to be monitored under the Unregulated Contaminant Monitoring Rule (UCMR) when analytical standards are validated. A third of freshwater cyanobacteria are capable of producing harmful toxins. Microcystin, cylindrospermopsin, and anatoxin-a are the toxins identified by the panel as having the highest priority relative to drinking water health effects.
Cylindrospermopsis is an expanding subtropical toxin that has been observed in the waters of many mid-Atlantic states as well as Kansas, Oklahoma, and Florida. An AWWA Research Foundation report found that of the samples collected in utility waters in the United States and Canada, 80 percent were positive for microcystins. It is now being found in finished (treated) water as well. Florida has detected as much as 90 µg/L of cylindrospermopsin in finished water, and several counties served from a plant on the Peace River had water that tested at five times safe levels for microcystin. In drinking water treatment, the coagulation/sedimentation/filtration process is reported to be between 90 and 99.9 percent successful at removing algae, but it is not effective at removing dissolved toxins. Physical removal of cells may be effective for toxins that tend to be retained in healthy cells such as microcystin, but is less effective for toxins that are released by healthy cells such as cylindrospermopsin.
The mechanisms of algal biotoxin’s toxicity are very diverse, ranging from hepatotoxic, neurotoxic, and dermatotoxic to general inhibition of protein synthesis. Studies on the occurrence, distribution, and frequency of algal toxins have suggested that hepatotoxins are the most prevalent. Animal and epidemiological studies suggest that low-level chronic exposure to microcystins increase human health risk of cancer and tumor growth promotion in the liver. Cylindrospermopsin’s primary target is also the liver, although recent studies have also found it to be carcinogenic and genotoxic (affects fetal development). In animal studies, the effects of this toxin have been widespread and progressive tissue injury, with cell necrosis in the liver, kidneys, adrenals, lung, heart, spleen, and thymus.Although the lack of markers for toxins has hindered the understanding of algal toxin health effects, it is clear that the presence of algae, and the production of secondary metabolites or toxins, is an emerging regulatory issue.
Since the World Health Organization (WHO) has developed a guideline value for the concentration of microcystin in finished drinking water (1 µg/L), the EPA has been reviewing the science behind the study and has accelerated its efforts to make regulatory decisions related to algae. Because regulatory decisions regarding contaminants on the CCL require information on health effects, susceptibility to treatment, and occurrence, a great deal of information gathering on algal toxins must first be completed. One of the main impediments to rule making is the lack of critical information (i.e., occurrence data) that must be obtained through the development and validation of analytical detection and monitoring methods.
Measuring Chlorophyll-a
While gas chromatography and immunosorbent assay methods can be used in a laboratory setting, there is an enormous demand for detection methods in the field as well. Lab analyses can become expensive and do not provide the continuous in-line monitoring desired by extensive field studies as will be required under the UCMR. One way to monitor for algal blooms is through the measurement of photosynthetic pigments, particularly chlorophyll-a, which estimates phytoplankton productivity. For the purposes of long-term monitoring and management programs, chlorophyll-a is the most widely used indicator of algal biomass.
Given the recent advancements in LED technology, the fluorometric method has become practical for field instrumentation. Chlorophyll, when excited by an external light source, absorbs light in certain regions of the visible spectrum and fluoresces (emits) light at longer wavelengths. By measuring the fluorescent intensity, chlorophyll concentration can be inferred, and early detection of toxin-producing algae can be achieved. In addition to the need to measure algae as part of the measurement and eventual regulation of toxins in drinking water, the EPA recommends that chlorophyll-a be monitored as a response variable under its water quality criteria for nutrients within ecoregions.
Algae and the toxins that they produce is an emerging regulatory issue that the EPA is examining. With the realization that algal toxins can pass through many conventional treatment methods, the water industry and regulators are moving forward to advance the science of algal toxins, gather information on occurrence, and ultimately provide guidelines and recommend treatment methods that potentially remove the health threat. The first beneficiaries within the water industry will be the analytical and/or instrumentation companies that develop standard methods for rapid detection, monitoring, and analysis.
Pharmaceuticals and Personal Care Products
Pharmaceuticals and personal care products, known in the water industry as PPCPs and in the medical community as endocrine disruptors, have been detected in trace amounts in surface water, drinking water, and wastewater effluent sampling conducted in both Europe and the United States. PPCPs are a group of compounds consisting of human and veterinary drugs (prescription or over the counter) and consumer products, such as fragrance, lotions, sunscreens, housecleaning products, and others. Water professionals have the technology today to detect more substances, at lower levels, than ever before. These compounds are being found at levels 1,000 times lower than where drinking water standards are typically set. As analytical methods improve, many compounds such as those listed above are being found at extremely low levels, typically single-digit parts per trillion. Drinking water standards are typically set in the parts-per-billion range, which is 1,000 times higher. PPCPs are the subject of extensive research to determine the human health impact from long-term exposure to trace amounts.
Table 13.1 Potentially Strategic Water Investments
The fact that a substance is detectable in drinking water does not mean the substance is harmful to humans. While these trace substances may be detected at very low levels in source waters, people regularly consume or expose themselves to products containing these substances in much higher concentrations through medicines, food and beverage, and other sources.The level in which they are found in source waters is very small in comparison. PPCPs are fairly common in our society and environment and come from many sources. Research on health effects for humans from PPCPs has focused on two areas:
1. While PPCPs are found in very low levels in drinking water, there is a concern of possible cumulative effects of long-term exposure.
2. PPCPs may react in ways that are different from their intended purpose once they are introduced into the environment.
Water professionals are researching the effectiveness of current treatment techniques on removal of PPCPs and other organic compounds. Because of the wide array of chemical structures and properties associated with PPCPs, no one single treatment can remove them all. Technologies under investigation include membranes and GAC, which physically remove compounds, and ozone or UV, which breaks them down. The EPA’s CCL does not currently include any PPCPs. See
Table 13.1 for other potentially strategic water investments.
