IWA affiliate

Status and Role of Water Reuse An International View Prepared by:

James Crook, Ph.D., P.E. Jeffrey J. Mosher Jane M. Casteline

August 2005

Global Water Research Coalition Alliance House 12 Caxton Street London SW1H 0QS United Kingdom Phone: + 44 207 654 5545 www.globalwaterresearchcoalition.net

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Global Water Research Coalition: Global cooperation for the generation of water knowledge

GWRC is a non-profit organization that serves as a collaborative mechanism for water research. The benefits that the GWRC offers its members are water research information and knowledge. The Coalition focuses on water supply and wastewater issues and renewable water resources: the urban water cycle. The members of the GWRC are: the Awwa Research Foundation (US), CRC Water Quality and Treatment (Australia), EAWAG (Switzerland), Kiwa (Netherlands), Suez Environment- CIRSEE (France), Stowa - Foundation for Applied Water Research (Netherlands), DVGW – TZW Water Technology Center (Germany), UK Water Industry Research (UK), Veolia- Anjou Recherché (France), Water Environment Research Foundation (US), Water Research Commission (South Africa), WateReuse Foundation (US), and the Water Services Association of Australia. These organizations have national research programs addressing different parts of the water cycle. They provide the impetus, credibility, and funding for the GWRC. Each member brings a unique set of skills and knowledge to the Coalition. Through its member organizations GWRC represents the interests and needs of 500 million consumers. GWRC was officially formed in April 2002 with the signing of a partnership agreement at the International Water Association 3rd World Water Congress in Melbourne. A partnership agreement was signed with the U.S. Environmental Protection Agency in July 2003. GWRC is affiliated with of the International Water Association (IWA).

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Disclaimer This study was jointly funded by GWRC members. GWRC and its members assume no responsibility for the content of the research study reported in this publication or for the opinion or statements of fact expressed in the report. The mention of trade names for commercial products does not represent or imply the approval or endorsement of GWRC and its members. This report is presented solely for informational purposes.

Copyright © 2005 by Global Water Research Coalition ISBN 90-77622-10-1 AwwaRF 2006, Used With Permission

Preface Water reuse is of growing interest to the members of the Global Water Research Coalition (GWRC). As a result, water reuse was selected as a priority area in the GWRC’s research agenda. In 2004, the GWRC Board of Directors decided to initiate a project with the aim of reviewing the present knowledge of water reuse and to organize a workshop to develop a phased research strategy. The WateReuse Foundation (WRF) was selected as GWRC’s lead organization for this research area. As a first step, WRF proposed to conduct a workshop on water reuse research needs. The objective of the workshop, which was held in Nieuwegein, the Netherlands in April 2005, was to develop a research strategy on water reuse for the GWRC. As a resource for the workshop, GWRC sponsored the development of this report to assess the current status of water reuse internationally. GWRC members contributed to the project by providing expert knowledge concerning water reuse in their countries and regions of the world. This report was prepared by James Crook, Ph.D., a water reuse consultant based in the United States, and Jeffrey J. Mosher and Jane M. Casteline, WRF staff members. The report was reviewed by GWRC member representatives.

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Contents Page 1.0 Introduction.............................................................................................................................. 1 2.0 Overview................................................................................................................................... 1 2.1 Microbial and Chemical Concerns ..................................................................................... 2 2.1.1 Microbial and Chemical Concerns ........................................................................... 2 2.1.2 Chemical Constituents............................................................................................. 5 2.1.3 Treatment Technologies ......................................................................................... 11 3.0 Country/Region Summaries.................................................................................................... 13 3.1 United States..................................................................................................................... 13 3.1.1 Applications............................................................................................................ 13 3.1.2 Regulations ............................................................................................................. 15 3.1.3 Public Perception/Acceptance ................................................................................ 18 3.2 Canada ............................................................................................................................. 22 3.3 Latin America (Central and South America)................................................................... 23 3.4 Europe.............................................................................................................................. 25 3.4.1 Applications............................................................................................................ 25 3.4.2 Technology ............................................................................................................. 27 3.4.3 Common Issues ...................................................................................................... 27 3.4.4 Regulations ............................................................................................................. 28 3.5 Middle East and North Africa ......................................................................................... 29 3.6 Southern Africa (South Africa and Namibia)................................................................... 37 3.6.1 South Africa ........................................................................................................... 37 3.6.2 Namibia .................................................................................................................. 38 3.7 Australia........................................................................................................................... 39 3.7.1 Applications............................................................................................................ 39 3.7.2 Regulations ............................................................................................................. 40 3.7.3 Public Perception/Acceptance ................................................................................ 41 3.8 Far East ............................................................................................................................ 41 4.0 Desalination of Seawater and Brackish Water....................................................................... 45 4.1 Status ................................................................................................................................ 45 4.2 Technologies.................................................................................................................... 47 4.2.1 Membrane Processes .............................................................................................. 47 4.2.2 Thermal Processes .................................................................................................. 49 4.2.3 Other Processes ...................................................................................................... 50 4.3 Other Factors ................................................................................................................... 51 4.3.1 Economics .............................................................................................................. 51 4.3.2 Concentrate Disposal.............................................................................................. 52 4.3.3 Energy Needs ......................................................................................................... 52 4.4 Desalination Research Needs ........................................................................................... 52 4.4.1 “Desalination Roadmap” Findings ......................................................................... 53 4.4.2 GWRC Survey Results ........................................................................................... 53 4.4.3 Results of the California (USA) Desalination Task Force Report ......................... 55 5.0 GWRC Survey Results .......................................................................................................... 56 5.1 Key Factors of Success Identified by GWRC Members ................................................. 56 5.1.1 Public Trust ............................................................................................................ 56 5.1.2 Pricing and Economics ........................................................................................... 57 AwwaRF 2006, Used With Permission

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5.1.3 Public Health and Environmental Protection ......................................................... 58 5.1.4 Guidelines and Regulations.................................................................................... 59 5.1.5 Planning, Management, and Applications.............................................................. 60 5.1.6 Improved Technologies and Monitoring ................................................................ 61 5.2 Priority Water Reuse Research Needs............................................................................. 62 5.2.1 Southern Africa ...................................................................................................... 62 5.2.2 Australia ................................................................................................................. 64 5.2.3 Europe .................................................................................................................... 66 5.2.4 United States........................................................................................................... 67 5.3 Potable Reuse Issues........................................................................................................ 70 5.3.1 Southern Africa ...................................................................................................... 70 5.3.2 Australia ................................................................................................................. 70 5.3.3 Europe .................................................................................................................... 71 5.3.4 United States........................................................................................................... 71 5.4 Ongoing, Planned, and Completed Research Projects..................................................... 72 6.0 Summary and Conclusions .................................................................................................... 73 7.0 References.............................................................................................................................. 76 Appendix A – GWRC Water Reuse Survey Form Appendix B – Completed GWRC Surveys by Region

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1.0 Introduction This report summarizes the current status of water reuse and is intended to serve as a background document in support of a Global Water Research Coalition (GWRC) Water Reuse Research Strategy Workshop that was held April 11-13, 2005 at Utrecht, the Netherlands. The purpose of the workshop was to identify and prioritize research needs related to water reuse to assist in the identification of research projects appropriate for consideration for collaborative funding by GWRC members. Based on selected published information and results of a recent GWRC member survey, the report addresses the status of water reuse in regions/countries where reuse is practiced, trends and drivers of reuse, current and ongoing research; and specific research needs. 2.0 Overview The treatment of wastewater and other impaired waters and their subsequent beneficial use commonly is called water reclamation and reuse, although different terms are used in various countries/regions. For example, some frequently-used terms include “water reuse,” “water recycling,” “water purification,” “reclaimed water,” “recycled water,” “reuse water,” and “repurified water.” For the purposes of this report, the following definitions apply: • • •

•

Reclaimed water = treated municipal wastewater and other impaired waters that are used for beneficial purposes. Water reuse = the use of reclaimed water for any purpose. Indirect potable reuse = augmentation of a raw water supply with reclaimed water followed by an environmental buffer. The mix typically receives additional treatment before distribution as drinking water. The definition of indirect potable reuse could be further broken down to “planned indirect potable reuse” (i.e., discharge of reclaimed water to a drinking water source with the intended purpose of augmenting the potable supply) or “unplanned indirect potable reuse” (i.e., discharge of treated wastewater to a drinking water source as a disposal method rather than as a purposeful means of augmenting a potable water supply.) The distinction between planned and unplanned indirect potable reuse varies from country to country and often is not well-defined. Direct potable reuse = introduction of reclaimed water directly into a water distribution system, without intervening storage (pipe-to-pipe).

Identification of “planned” versus “unplanned” or “incidental” water reuse projects may be important from a regulatory standpoint but is of lesser importance when considering the practical acceptability of the practice, as the result is the same (i.e., wastewater is reused for a beneficial purpose). Unplanned or incidental reuse is widely practiced throughout the world. A schematic diagram depicting different types of water reuse is provided in Figure 1. Water reclamation and reuse began on a large scale about 150 years ago when cities began using flush toilets and sewerage systems. By the late 1800s, there were several “sewage farms” in Europe and elsewhere where untreated wastewater was used for agricultural irrigation; in most cases, the main purpose was to provide for disposal of the wastewater, and any agricultural benefits from the farms were incidental. This method of disposal was replaced by discharge of effluent to rivers, streams, and other waters with the advent of biological treatment processes in the early 1900s. In the first half of the 20th century, reclaimed water was used almost exclusively for agricultural irrigation. Advances in treatment technology, public health, microbiology, and AwwaRF 2006, Used With Permission

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Figure 1. Schematic of Water Use Industrial water use

Atmospheric water vapor Water treatment

Municipal use

Precipitation

Waste water reclamation/reuse surface water

Irrigation Surface water

Ground water

Ground water Ground water recharge

Potable reuse

Source: Courtesy of Frans Schulting, GWRC

monitoring resulted in additional uses of reclaimed water. Today, reclaimed water applications range from pasture irrigation, where minimal treatment is acceptable, to potable reuse, where extensive treatment is needed to meet drinking water standards. Agricultural irrigation continues to be the major use of reclaimed water in most developing countries, while the trend in some industrialized countries has shifted to landscape irrigation and other uses in urban areas, industrial and commercial applications, and potable reuse. Lazarova and Asano [2005] recently summarized water reuse activities in several countries (Table 1). Water reuse regulations and guidelines vary considerably from country to country and even within countries. Most countries that engage in water reuse have either developed their own standards or guidelines or use those developed by others (e.g., the World Health Organization Guidelines for the Use of Wastewater for Agriculture and Aquaculture [World Health Organization, 1989]). In general, regulations in industrialized countries tend to be more restrictive than those in developing countries. Technical capability and social, economic, and cultural conditions influence regulatory requirements. Arguments for less restrictive standards are often predicated upon a lack of documented health hazards rather than upon any certainty that hazards are small or nonexistent. In the absence of a common interpretation of scientific data, selection of water quality criteria will continue to be somewhat subjective and inconsistent. Although regulations and guidelines vary among and within countries, they generally are based on health protection from microbial pathogens and, thus, become more restrictive as the expected degree of human contact with the reclaimed water increases. The comparative stringency of regulations and guidelines for a range of uses is indicated in Table 2. 2.1 Microbial and Chemical Concerns 2.1.1 Microbial Pathogens The most common concern associated with the reuse of treated municipal wastewater is the potential transmission of infectious disease, primarily by enteric pathogens. Many of the pathogens potentially present in untreated wastewater are well-documented in the literature AwwaRF 2006, Used With Permission

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Table 1. Overview of Water Reuse (Selected Countries) Country/ State Argentina Australia Belgium Canada Chile Chinab Egyptb France Indiab Israel Italy Japan Jordan Kuwait Namibia Mexicob Moroccob Oman South Africa Saudi Arabia Spain Sweden Tunisia United Arab Emirates UK USA - Arizona - California - Florida a

Water Reuse Activitya

Reuse Guidelines/ Regulations

medium high medium medium low medium medium medium high intensive medium high high intensive medium medium medium high

Yes Yes No Yes

Percent Water Consumption by Sector

Water Reuse Applications a

Urban 16 12

Industry 9 6

Agriculture 75 70

Irrigation ++ ++

No No Yes No Yes Yes Yes Yes Yes No No No Yes

11 5 5 6 15 5 29 14 19 22 37 28 17 5 5

68 11 18 8 73 3 7 33 17 3 2 3 5 3 2

7 84 77 86 12 92 64 53 64 75 60 68 78 92 93

+ ++ + ++ +++ +++ ++ ++ ++ + + +++ ++ ++

high

Yes

17

11

72

++

+

intensive

Yes

9

1

90

+++

++

high low medium

Yes

18 30 3

68 4 83

++ + ++

+

Yes

13 35 14

intensive

Yes

24

10

67

+

++

medium high high intensive high

Yes Yes Yes Yes Yes

65 11

8 44

2 40

+ ++ ++ +++ +++

++ + + ++ ++

Potable

+ + +

Subjective evaluation based on literature: +++ numerous, ++ occasional and + isolated projects. Countries using raw sewage for irrigation.

b

Source: Adapted from: Lazarova and Asano [2005]

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+ ++ +++

+

++ + + +

+ + ++ +

Table 2. Comparative Stringency of Regulations/Guidelines Depending on Type of Reuse Stringency of Regulations and Guidelines

Type of Use Potable reuse Agricultural irrigation of food crops eaten raw (direct contact between water and edible portion of crop) Unrestricted recreational impoundments (full body contact allowed) Unrestricted urban irrigation (park, playground, schoolyard, residential lawn irrigation) Restricted urban irrigation (golf courses, roadway medians, etc.) Restricted recreational impoundments (boating, fishing, incidental contact allowed) Agricultural irrigation of food crops (no direct contact between water and edible portion of crop) Aquaculture Industrial reuse (cooling water) Processed food crops (commercial processing to destroy pathogens) Environmental reuse (wetlands, stream flow augmentation) Construction uses (soil compaction, dust control, etc.) Agricultural reuse on non-food crops (fodder, fiber, & seed crops)

More Stringent

L L L L L L L L L L L Less Stringent

[Blumenthal et al., 2004; 2000; Carr et al., 2004; Hurst et al., 1989; National Research Council, 1996; National Research Council, 1998; National Research Council, 2004; Radcliffe, 204; Sagik, et al., 1978; U.S. Environmental Protection Agency, 2004]. The principal source of pathogens in wastewater is the feces of infected individuals, but some enteric pathogens also affect other animals and therefore have animal reservoirs; thus, the types and concentrations of pathogens in any particular wastewater depend to a large extent on the health of the contributing population. For example, helminth infections are far less common in Europe, Australia, and the United States than in China, India, and the Middle Eastern countries. Of equal concern to microbiologists and public health officials are new, emerging, or reemerging pathogens. Emerging infectious diseases have been defined as those whose incidence in humans have increased within the past two decades or threaten to increase in the near future [Institute of Medicine, 1992]. Selected emerging and reemerging waterborne pathogens are listed in Table 3. Some – but not all – of the pathogens listed in Table 3 have been found in municipal wastewater. Fungi (i.e., yeasts and molds) are ubiquitous in the environment, although only a few of the more than 100,000 known fungi are known to be pathogenic to humans [National Research Council, 2004]. Given the ubiquity of molds and fungi in water samples, some experts indicate that research is needed to clarify their role in the transmission of waterborne diseases. Two types of aquatic microorganisms, aeromonads and cyanobacteria, may be of concern for potable reuse systems if sufficient nutrients are present to create blooms of these organisms resulting in increased production of toxin [National Research Council, 1998]. The possible AwwaRF 2006, Used With Permission

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Table 3. Emerging and Reemerging Waterborne Pathogens of Public Health Concern Bacteria

Viruses

Protozoa

Aerobacter

Adenoviruses

Acanthamoeba

Aeromonas hydrophila

Astrovirus

Cryptosporidium parvum

Campylobacter (including C. jejuni, C. coli, and related species

Coxsackieviruses

Cyclospora cayetanensis

Echoviruses

Giardia lamblia

Enteroviruses

Microsporidia

Hepatitis viruses

Toxoplasma gondii

Helicobacter pylori Legionella spp. Mycobacterium avium complex

Norwalk/Caliciviruses Rotavirus

Pathogenic Escherichia coli Pseudomonas aeruginosa Yersinia enterocolitica Source: Adapted from: National Research Council [2004]

health significance of aeromonads led the Netherlands to develop drinking water guidelines for the concentration of the organisms after treatment and in the distribution system [van der Kooij, 1993]. In response to the potential health threat from cyanobacteria, the Engineering and Water Supply Department of South Australia developed interim guidelines for acceptable numbers of cyanobacteria in drinking water supplies [El Saadi et al., 1995]. While molecular techniques are used to assess water for certain pathogens, they generally are organism-specific and often only indicate the presence or absence of genetic material in the sample – not concentration or viability. Thus, their utility in evaluating the safety of reclaimed water for any particular use is somewhat limited at the present time. It is impractical to monitor reclaimed water for all microbial pathogens, and indicators for waterborne pathogens are universally used. The principal indicators are total coliform, fecal coliform, Escherichia coli, and enterococci. Bacteriophage also has been used as an indicator of enteric viruses. None of the existing indicators or combination of existing indicators is capable of predicting the presence of all waterborne pathogens. Water reuse regulations generally require a combination of treatment requirements and water quality criteria that have been shown by research or operating experience to produce acceptable product water. 2.1.2 Chemical Contaminants With a few exceptions (e.g., where municipal wastewater contains significant amounts of potentially toxic industrial wastes), there are minimal health concerns associated with chemical constituents where reclaimed water is used for irrigation or other nonpotable applications. Pesticides, heavy metals, and organic chemicals are usually reduced to acceptable limits by conventional wastewater treatment and would not be expected to present any risks to health from contact or inadvertent infrequent ingestion of reclaimed water. The health effects related to the AwwaRF 2006, Used With Permission

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chemical constituents are of primary concern with regard to potable reuse. Both organic and inorganic constituents need to be considered where reclaimed water is utilized for food crop irrigation, where reclaimed water from irrigation or other beneficial uses reaches potable groundwater supplies, or where organics may bioaccumulate in the food chain (e.g., in aquaculture applications). Some inorganic and organic constituents and their potential significance in water reclamation and reuse are summarized below. •

Biodegradable organics: Biodegradable organics can create aesthetic and nuisance problems. Organics provide food for microorganisms, adversely affect disinfection processes, make water unsuitable for some industrial or other uses, consume oxygen, and may cause acute or chronic health effects if reclaimed water is used for potable purposes.

•

Stable organics: Some organic constituents tend to resist conventional methods of wastewater treatment. If not eliminated or reduced to low levels in reclaimed water, their presence may limit the suitability of reclaimed water for some applications, particularly potable reuse. Total organic carbon (TOC) is the most common monitoring parameter for gross measurement of organic content in reclaimed water used for potable purposes. TOC is used as a measure of treatment process effectiveness; at the present time, it is not possible to specify a maximum contaminant level for TOC based on health effects data [National Research Council, 1998].

•

Nutrients: Nitrogen, phosphorus, and potassium are essential plant nutrients for plant growth, and their presence normally enhances the value of the water for irrigation. When discharged to the environment, nitrogen and phosphorus can lead to the growth of undesirable aquatic life. When applied at excessive levels on land, the nitrate form of nitrogen will readily leach through the soil and may cause groundwater concentrations to exceed drinking water standards.

•

Hydrogen ion concentration: The pH of wastewater affects disinfection efficiency, coagulation, metal solubility, and alkalinity of soils. Normal pH range in municipal wastewater is 6.5 to 8.5, but industrial wastes may have pH characteristics well outside of this range.

•

Heavy metals: Some heavy metals such as cadmium, copper, molybdenum, nickel, and zinc accumulate in crops to levels that are toxic to consumers of the crops. Heavy metals in reclaimed water that has received at least secondary treatment are generally within acceptable levels for most uses; however, if industrial wastewater pretreatment programs are not enforced, certain industrial wastewaters discharged to a municipal wastewater collection system may contribute significant amounts of heavy metals.

•

Dissolved inorganics: Excessive salinity may damage some crops. Specific ions such as chloride, sodium, and boron are particularly toxic to some crops. Sodium may pose permeability problems. Residential use of water in the U.S. typically adds about 300 mg/L of dissolved inorganic solids, although the amount added can range from approximately 150 mg/L to more than 500 mg/L [Metcalf & Eddy, 2002].

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•

Residual chlorine: Excessive amounts of free available chlorine may cause damage to some sensitive crops. However, most chlorine in reclaimed water is in a combined form, which does not generally cause crop damage. The reaction of chlorine with organics in water creates a wide range of disinfection byproducts (DBPs), some of which may be harmful to health when ingested over the long term. DBP levels – as well as pesticide and heavy metal levels – in tertiary treated wastewater generally are below maximum contaminant levels (MCLs) in drinking water standards [National Research Council, 1998].

•

Suspended solids: Suspended matter can shield microorganisms from disinfectants and react with disinfectants such as chlorine or ozone to lessen disinfection effectiveness. It is essential to remove suspended solids where ultraviolet radiation is used as the disinfection process to destroy or inactivate microbial pathogens to low or undetectable levels in reclaimed water. Suspended solids can lead to sludge deposits and anaerobic conditions if discharged to the aquatic environment. Excessive amounts of solids cause clogging in irrigation systems or accumulate in soil and affect permeability.

Effects of physical parameters (e.g., pH, color, temperature, and particulate matter) and chemical constituents (e.g., chlorides, sodium, and heavy metals) are well known, and recommended limits have been established for many constituents [National Academy of Sciences-National Academy of Engineering, 1973; Radcliffe, 2004; U.S. Environmental Protection Agency, 1981; Westcot and Ayers, 1985; Water Pollution Control Federation, 1989; U.S. Environmental Protection Agency, 2004]. The effect of organic constituents in reclaimed water used for crop irrigation may warrant attention if industrial wastes contribute a significant fraction to the wastewater. Highly toxic organic compounds have been found in reclaimed water used for potable reuse, such as N-nitrosodimethylamine and 1,4-dioxane. At present, no surrogate parameters or group of surrogate parameters have been identified that are capable of indicating the presence of many individual or types of organic compounds having health significance. Traditional measures of organic matter in wastewater, such as BOD, COD, and TOC are used as measures of treatment efficiency and general water quality. TOC is not an adequate indicator of the safety of reclaimed water related to chemical constituents, since many chemicals are carcinogenic or otherwise hazardous at levels far below commonly measured TOC levels. There has been a great deal of interest and, in some cases, concern, regarding human health effects associated with pharmaceuticals, hormones, and other organic wastewater contaminants. Chemicals that interfere with endocrine systems of humans and wildlife are termed endocrine disrupting compounds (EDCs). Chemicals that elicit a pharmaceutical response in humans are termed pharmaceutically active compounds (PhACs). EDCs and PhACs are not mutually exclusive classifications, as some, but not all, PhACs are also EDCs. Endocrines are chemicals used by organisms to regulate important metabolic activities, such as ion balance, reproduction, basal metabolism and “fight or flight” responses, through changes in hormones secreted by the thyroid, parathyroid, pituitary, adrenal, sex, and other glands. At the present time, more than 4,000 compounds have been reported to show endocrine disrupting properties, primarily in relation to estrogen effects [Global Water Research Coalition, 2003a], and more than 60 PhACs have been identified that impact the endocrine system of animals or humans in nanogram/liter (ng/L) or lower concentrations in the ecosystem. Pharmaceuticals and personal care products (PCPs) are sometimes called PPCPs, which comprise a very broad, diverse collection of AwwaRF 2006, Used With Permission

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thousands of chemicals, including prescription and over-the-counter drugs, fragrances, cosmetics, sun screen agents, diagnostic agents, and many other compounds. Available data collected by member agencies of the GWRC indicate that EDCs are found in all types of waters (i.e., groundwater, surface water, drinking water, and treated wastewater) with concentrations of different classes of EDCs ranging from ng/L to µg/L levels [Global Water Research Coalition, 2003b]. In recognition of the fact that monitoring the entire spectrum of potential EDCs in water and wastewater would be cost-prohibitive, the GWRC developed a priority list of EDCs (presented in Table 4) that would provide a basis for credible analytical determination of EDCs in water. It is understood that the priority list of EDCs is dynamic and additions or deletions to the list may be made as additional information becomes available. Table 4. GWRC Priority List of Endocrine Disrupting Compounds Pesticides and Herbicides Aldrin Cyhexitin DDT DDE DDD Dieldrin Endosulphan-sulphate

α-Endosulphan β-Endosulphan Endrin Heptachlor Heptachlor epoxide Isodrin Lindane (?-BHC)

Hormones

Metoxychlor Parathion Simazine Terbutylazine Tributylin Vinclozolin

Industrial Chemicals

17α-ethinylestradiol 17β-estradiol Estriol Estrone

Bisphenol A Glycol ethers p-Nonylphenol p-Octylhenol PCB (total) Phthalates: DBP, DEPH

Heavy Metals Cadmium Source: Global Water Research Coalition [2003a]

Most of the research to date has been directed at the presence, concentration, and effects of pharmaceuticals, personal care products, and endocrine disrupting compounds – or their metabolites – on the aquatic environment, where these constituents have been shown to have adverse effects on aquatic animals such as frogs and fish. Less is known about the presence, concentration, and human health effects (including additive/synergistic effects) associated with these chemicals resulting from long-term ingestion of potable water, although it has been reported that several researchers who conducted risk evaluations concluded that there is no appreciable risk to humans at the low levels of the chemicals found in drinking water [Global Water Research Coalition, 2004]. Mons et al. [2003] estimated that the lifetime intake of pharmaceuticals from drinking water, based on drinking 2 liters/day for 70 years, is far below the therapeutic dose. However, most experts agree that toxicological data are lacking on the human and environmental significance of PhACs with regard to subtle long term effects, and thus, exposure to these substances should be minimized. AwwaRF 2006, Used With Permission

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Toze [2005] conducted an extensive literature review on chemical constituents in reclaimed water and concluded there is a minimal potential health impact from EDCs in reclaimed water used for nonpotable purposes due to their low concentration and very small potential doses resulting from contact with the water. Similarly, a Global Water Research Coalition report states that exposure to PhACs and EDCs that may occur during recreation in surface water containing reclaimed water is considered to be negligible due to the low frequency of exposure and low quantity of water that would be ingested [Global Water Research Coalition, 2004]. In contrast, Rajapakse et al. [2002] reported that experiments using a combination of 11 xenoestrogens (i.e., man-made estrogenic chemicals) and 17β-estradiol, each present at a level below its noobserved-effect concentration, demonstrated that the xenoestrogens were able to modulate significantly the estrogenic effects of 17β-estradiol. The authors cautioned that additive combination effects of xenoestrogens deserve serious consideration. Many commonly used pharmaceuticals are ubiquitous in wastewater effluents. In conventional wastewater treatment plants, they can be removed or reduced in concentration by microbial degradation, adsorption to particulates that are removed during wastewater treatment, or by biotransformation. Research on wastewater samples collected at several wastewater treatment plants in California indicate that secondary effluent contains estrogenic hormone concentrations comparable to those that cause vitellogenesis (i.e., feminization) in fish and that filtration of secondary effluent removes approximately 70% of the hormones from secondary effluent [Huang and Sedlak, 2001]. The synthetic oral contraceptive 17α-ethinylestradiol is suspected, in combination with the steroidal estrogens 17β-estradiol and estrone, of causing vitellogenin production in male fish. Desbrow et al. [2002] identified estrone, 17α-ethinylestradiol, and 17βestradiol as compounds associated with high estrogenic activity in treated municipal wastewater in the United Kingdom. A partial list of PhACs and PCPs frequently found in wastewater effluents and the aquatic environment is provided in Table 5. The chemicals listed in Table 6 are based on a literature review by Drewes et al. [2003] for selected endocrine disrupting compounds found in secondary treated municipal wastewater. All are generally found – if at all – at ng/L levels except for the alkylphenols, which in total may be in the µg/L range. The literature reviewed indicates that activated sludge secondary treatment removes EDCs more effectively than secondary treatment using the trickling filter process. Further, long retention times and nitrification/denitrification during activated sludge treatment enhanced removal of EDCs. While conventional secondary and tertiary treatment efficiently removes some pharmaceuticals, removal or reduction of others is highly variable [Buser and Muller, 1999; Ternes, 1998]. Advanced wastewater treatment processes such as reverse osmosis are capable of removing most EDCs and PhACs to undetectable levels in the product water. Ozone also is an effective treatment process to reduce the concentrations of many of these chemicals to low levels. A review of the scientific literature did not provide any information on whether or not pharmaceuticals and endocrine disrupting compounds become concentrated on vegetation or in soil via irrigation with reclaimed water. Drugs detected in the environment are generally in the µg/L - ng/L range and many have short half-lives (i.e., they do not persist for long periods in the environment) and may not pose much acute risk [Daughton and Ternes, 1999]. There is increasing concern regarding antibiotic resistance in microbial pathogens. There is a correlation between antibiotic use and the appearance of antibiotic-resistant bacteria in the AwwaRF 2006, Used With Permission

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Table 5. Pharmaceutically Active Compounds and Personal Care Products Observed in Treated Wastewater and/or the Aquatic Environment Area of Application

Compounds

Pharmaceutically Active Compounds Analgesics/anti-inflammatory drugs

Acetaminophen, Acetylsalicylic acid, Diclofenac, Dimethylaminophenazone, Fenoprofen, Ibuprofen, Ketoprofen, Meclofenamic acid, Naproxen, Paracetamol, Phenazone, Tolfenamic acid,

Antibiotics

Amoxicillin, Ciprofloxacin, Erythromycin, indometacine, oxytretacyclin, Sulfachlorpyridazine, Sulfamerazine, Sulfamethazine, Sulfamethoxazole, Sulfamethoxine, Sulfathiazole, Trimethoprim

Anti-epileptics

Carbamazepine, Primidone

Anti-neoplastic agents

Cyclophosphamide, Ifosfamide

Beta-blockers

Betaxolol, Bisoprolol, Carazolol, Matoprolol, Nadolol, Propranolol, , Sotolol, Timolol

Lipid regulators

Bezafibrate, Clofibric acid, Fenofibric acid, Gemfibrozil

Tranquillizers

Diazepam

Esrogens

17α-ethinylestradiol

Diagnostic agents

Amidotrizoic acid, Diatrizoate, Iomeprol, Iopamidol, Iopromide

Personal Care Products Nitromusks

Musk ketone, Musk xylene

Polycyclic musks

Celestoide, Galaxolide, Tonalide

Anti-bacterial agents

Triclosan

Source: Drewes et al. [2001]; Global Water Research Coalition [2004]

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Table 6. Typical Concentration Ranges of Selected Endocrine Disrupting Chemicals in Secondary-Treated Municipal Wastewater Compound

Concentration In Secondary Effluent

Estrogen (ng/L) Testosterone (ng/L) Estrone (ng/L) 17β-estradiol (ng/L) Estriol (ng/L) 17α-ethinylestradiol (ng/L) Bisphenol A (ng/L) Alkylphenols (total) (µg/L)

1.4 – 76 50 1.4 – 7.6 2.7 – 48