RESTORATION AND MANAGEMENT OF LAKES AND RESERVOIRS - CHAPTER 10 doc

10 Copper Sulfate 10.1 INTRODUCTION Copper, an effective algicide, is registered for use in potable water supplies. Its effects are temporary (days), annual treatment costs can be high, there are major negative impacts to non-target organisms, and significant copper contamination of sediments is possible. Several U.S. states have started to restrict or phase out copper use or to lower the permissible dose. The search for an alternative algicide with fewer negative effects has been unsuccessful. Copper sulfate is also used in tank mixes of herbicides to enhance macrophyte control (Chapter 16). The purposes of this chapter are to describe copper sulfate’s dose and application procedures, and to discuss its positive and negative effects. There are several reviews of copper use for algae control (i.e., AWWARF, 1987; Cooke and Carlson, 1989; Demayo et al., 1982; McKnight et al., 1981, 1983; Raman and Cook, 1988). 10.2 PRINCIPLE OF COPPER SULFATE APPLICATIONS The primary toxic form of copper to algae is the cupric ion (Cu 2+ ) (McKnight et al., 1981), although other forms such as copper-hydroxy complexes may also be toxic (Erickson et al., 1996). Effects on algae include inhibitions of photosynthesis, phosphorus (P) uptake, and nitrogen fixation (Havens, 1994), but effects vary with algal species. Cyanobacteria are particularly sensitive, with concentrations as low as 5–10 μg Cu/L suppressing activity (Demayo et al., 1982; Horne and Goldman, 1974). Copper treatments are likely to be most effective in controlling blooms of nitrogen fixing cyanobacteria, possibly through frequent low doses (Elder and Horne, 1978). The activity of the cupric ion is affected by: (1) inorganic complexation, (2) precipitation (Cu(OH) 2 CO 3 , CuO, CuS), (3) complexation with compounds such as humic and fulvic acids, (4) adsorption on materials such as clays, and (5) biological uptake (McKnight, 1981; McKnight et al., 1981, 1983; Fitzgerald, 1981). Effective doses therefore may vary among lakes. pH has a significant effect on the appearance of the cupric form (Cu 2+ ), requiring higher CuSO 4 doses in lakes with high alkalinity and pH (Figures 10.1 and 10.2). Copper is less toxic in hard water, in part due to the precipitation of malachite (Cu(OH) 2 CO 3 ) and to competition with calcium and magnesium for binding sites on the algal cell membrane. The experiments by Button et al. (1977) in Hoover Reservoir (alkalinity = 96 mg/L as CaCO 3 , pH = 7.8), a water supply for Columbus, Ohio, illustrate the brief period of high Cu 2+ that can be expected in a water body of this alkalinity. Cu 2 + concentration in the water column fell rapidly after the application of 1.56 g CuSO 4 ⋅ 5H 2 O/m 2 . About 95% of the total CuSO 4 dissolved in the top 1.75 m of the water column. At the end of 2 h, soluble Cu 2+ fell to pre-treatment levels (Figure 10.3), perhaps through precipitation, dilution by incoming water, or by washout. An algae bloom, consisting of taste and odor causing diatoms Melosira sp., Asterionella sp. and Stephanodiscus sp., was controlled. Formation of insoluble malachite may have been responsible for a substantial fraction of the loss of Cu 2+ because conditions for its formation were ideal (Button et al., 1977). Complexation by dissolved humic substances in Mill Pond Reservoir, a Massachusetts water supply with a high humic content, apparently prevented the rapid loss of copper to the lake’s bottom, making the treatment more effective. Biomass of the taste and odor causing dinoflagellate, Ceratium Copyright © 2005 by Taylor & Francis FIGURE 10.1 Relationship between pH and concentration and forms of copper in high alkalinity water. (From McKnight, D.M. et al. 1983. Environ. Manage. 7: 311–320. With permission.) FIGURE 10.2 Relationship between pH and concentration and forms of copper in low alkalinity water. (From McKnight, D.M. et al. 1983. Environ. Manage. 7: 311–320. With permission.) − log Cu T 4 5 6 7 5678910 pH Cu 2+ CuCO 3 (aq.) Malachite Cu 2 (OH) 2 CO 3 (s) Tenorite CuO (s) (CuCO 3 ) 2 2− − log Cu T 4 5 6 7 5678910 pH Cu 2+ CuCO 3 (aq.) Malachite Cu 2 (OH) 2 CO 3 (s) Tenorite CuO (s) Cu(OH) − 3 Copyright © 2005 by Taylor & Francis hirundinella, was reduced by 90%, although the green algae Nanochloris and Ourococcus were unaffected by the complexed copper and appeared to be copper tolerant (McKnight, 1981). In this case, the dose of CuSO 4 saturated the organic complexing agent and still provided enough Cu 2+ to control the dinoflagellate. Presumably, much higher doses would have been needed to control the other species. The effectiveness of copper has been enhanced by either complexing copper with a carrier molecule, or by chelating it to non-metal ions, to keep copper in solution (DuBose et al., 1997). These formulations allow effective treatment at lower doses. Mat-forming filamentous algae can be pond and littoral zone nuisances, and doses to control them vary widely. Using Cutrine-Plus (Applied Biochemists, Milwaukee, WI 53218, U.S.), an ethanolamine–copper complex, Oedogonium and Spirogyra had a very low EC 50 of 3 μg Cu/L (dose producing a 50% biomass reduction), but Hydrodictyon, Pithophora, and Rhizoclonium were 15 times more tolerant, and Oscillatoria was six times more tolerant than Pithophora (Lembi, 2000). Field dose ranges could be wider than these laboratory doses, indicating the need for correct identification of algae and for recognition that Pithophora, Oscillatoria, and Lyngbya form thick mats or “scums” that may resist copper penetration. 10.3 APPLICATION GUIDELINES Guidelines for CuSO 4 treatments for planktonic algae were developed by Mackenthun (1961). However, reservoirs and lakes are sufficiently unique to require experience and judgment of the applicator for the dose most likely to produce control. These are Mackenthun’s guidelines: For lakes with a methyl orange alkalinity > 40 mg/L as CaCO 3 , the dose for planktonic algae is 1.0 mg CuSO 4 ⋅ 5H 2 O/L, as copper sulfate crystals, for the upper 0.3 m depth regardless of actual depth. In water with this alkalinity, 0.3 m is considered the maximum effective depth range, after which copper is rapidly lost to complexation. If alkalinity is < 40 mg/L, the dose is 0.3 mg CuSO 4 5H 2 O/L. Copper sulfate is more effective at water temperatures > 15°C. Doses at these concentra- tions will be toxic to many species of algae and to some non-target organisms (Nor, 1987). Control of Chara and Nitella requires a dose of 1.5 mg/L, or higher, and must be applied early in the season before these algae become encrusted with marl. FIGURE 10.3 Depth of soluble copper penetration after application to Hoover Reservoir, OH. (From Button, K.S. et al. 1977. Water Res. 11: 539–544. With permission.) Cu 2+ mg/l 0.3 0.2 0.1 Surface 1 m 3 m 16 m No sample 0 0.1 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Time, hr Copyright © 2005 by Taylor & Francis Applicators may increase doses to compensate for copper sulfate ineffectiveness when water column conditions promote complexation and precipitation. At a water column pH of 8.0, less than 10% of the added copper is in the dissolved form. Photosynthesis can drive pH up to 9 or above, and copper effectiveness will be minimal. A chelated or complexed form may be needed in high alkalinity waters (Raman and Cook, 1988). Planktonic and filamentous algae are rarely controlled with a single application. The “guideline” dose of 1.0 mg/L as CuSO 4 ⋅ 5H 2 O for waters with alkalinity > 40 mg/L as CaCO 3 (Mackenthun, 1961: Fitzgerald, 1967) is often followed, but it appears that lower doses (e.g., 0.15 mg/L) at daily intervals for 3–5 days could be more effective (DuBose et al., 1997). The problems with low doses, however, are algal tolerance (McKnight et al., 1981; Twiss et al., 1993), the rapid loss of copper via complexation, precipitation, or washout to concentrations that are too low, and the costs associated with re-applications. Treatment methods range from the traditional burlap bag of CuSO 4 towed behind a boat, to mechanical spreaders, sprayers, and helicopters. Large quantities (e.g., 4,500 to 7,000 kg per day) have been applied to water supply reservoirs, using barges and chemical spreaders (McGuire et al., 1984) to treat taste and odor causing periphytic species of Oscillatoria. Copper can be added to a reservoir’s inflow (Bean, 1957), or introduced near an artificial circulation device. Recreational lake users may wait until an algal bloom develops before making application, an approach that could be effective, although severe dissolved oxygen (DO) depletions are possible. Water supply managers face the problem of preventing episodes of unacceptable tastes and odors, or the appear- ance of a bloom of a toxic algal species. Some potable water supply operators monitor the algal community on a frequent and regular basis during the summer and fall and treat the reservoir to prevent a “bloom.” This may require several treatments. This approach emphasizes the need for continuous and detailed monitoring of the water body. 10.4 EFFECTIVENESS OF COPPER SULFATE The chemical and hydrological features of the treated water determine how rapidly copper will be lost through precipitation, adsorption, washout, or dilution. There have been suggestions that some algae species population have become resistant to low doses of copper, thus requiring either the chelated or complexed forms, or a greater concentration, for effectiveness. These and other factors are significant in the few published case histories about algae responses to copper. The experimental treatments to periphytic blue-green algae in the highly buffered (alkalinity 150 mg/L as CaCO 3 ) Casitas Reservoir, California are among the few published case histories about control of these taste and odor producing algae (AWWARF, 1987). Several chelated and non- chelated copper compounds were studied for effects on Oscillatoria limosa and other species of this genus. Dry CuSO 4 crystals in chelated (ethanolamine) and non-chelated forms were applied to surface waters over the periphyton mats, at doses from 0.2 to 0.3 mg Cu/L (chelated) and 0.4 to 1.7 mg Cu/L (non-chelated). Liquid copper citrate (chelated) and CuSO 4 solutions were applied directly on the periphyton via a submerged hose, at 0.2 to 2.2 mg Cu/L and 0.2 to 1.0 mg Cu/L, respectively. Divers were used to monitor results and water samples were obtained to determine changes in taste and odor causing compounds. The submerged applications of CuSO 4 and CuSO 4 citrate solutions at Casitas Reservoir had little effect on periphyton. Applications of CuSO 4 at 1.7 mg Cu/L to the lake’s surface, based on an estimated volume of water near the periphyton growths, had some effect but produced significant benthic invertebrate mortality. Application of chelated granular copper to the surface at doses of 0.2 to 0.4 mg Cu/L was effective at periphyton control, but regrowth was apparent in 4 weeks. This formulation was toxic to benthic invertebrates and was the most costly treatment (Table 10.1). Copper use was stopped at Casitas Reservoir due to environmental concerns. Copper sulfate treatments of nuisance phytoplankton “blooms” frequently are successful for brief periods. Species other than the target algae may become dominant, or algal biomass may Copyright © 2005 by Taylor & Francis “rebound” to levels similar to or higher than the original bloom condition. Copper sulfate is unquestionably effective as long as the cupric ion concentration remains high, but water masses are hydraulically dynamic, leading to washout, dilution, and reinoculation with algae, and chemical and physical conditions may lead to loss of copper. In situations where eutrophication continues, increasingly frequent and heavier doses may be needed (Hanson and Stefan, 1984). Copper sulfate has been used to kill snails in bathing beach areas to limit the release of immature (cercaria) forms of the blood flukes (Trematoda, Schistosomatidae) that penetrate human skin, causing “swimmer’s itch.” Humans are not the normal host and the cercaria die in the skin, producing severe itching. The Minnesota Department of Natural Resources (undated pamphlet) recommended treating with 1.5 kg/100 m 2 out to the edge of the littoral zone. This dose is lethal to most invertebrates and could produce sediment contamination. 10.5 NEGATIVE EFFECTS OF COPPER SULFATE The benefits of copper sulfate treatments for algae control in recreational lakes should be weighed against the exposure of non-target organisms to concentrations of a heavy metal greater than the median lethal dose from laboratory studies. Copper sulfate negatively impacts aquatic communities, and could create human health problems. Resistance may develop in target algae, and algae grazing by zooplankton may be eliminated. Dissolved oxygen depletions can occur when large volumes of dead algal cells decompose, creating conditions causing increases in iron, P, manganese, hydrogen sulfide, and ammonia concentrations. Laboratory test procedures for copper toxicity often involve exposure of the test organism for 96 h, a test period that may obscure effects. Copper is rapidly lost from solution, even with highly simplified, possibly soft-water, experimental conditions, suggesting that 48-h exposures may be more realistic in determining an LC 50 (concentration lethal to 50% of test organisms) (Mastin and Rodgers, 2000). Laboratory toxicity tests have demonstrated lethal and sublethal effects on bluegills (Lepomis macrochirus). The 96-h LC 50 ranged from 1.0–3.0 mg Cu/L (Blaylock et al., 1985), to as high as 16.0 mg. Cu/L (Ellgaard and Guillot, 1988) in test waters of moderate alkalinity (46–82 mg/L as CaCO 3 ). However, locomotor activity was impaired at much lower concentrations (e.g., 40 μg Cu/L; Ellgaard and Guillot, 1988). Hatchability and survival of 4-day old larvae were affected by concentrations above 77 μg Cu/L (Benoit, 1975). The risk of direct bluegill mortality apparently is low, but sublethal effects on behavior and reproduction, and on feeding behavior, could lead to reduced growth, and occur at concentrations more than an order of magnitude less than recommended for algae treatment (Sandheinrich and Atchison, 1989). Other species (e.g., trout) may be even more copper sensitive. Does copper accumulation in lake sediments pose a bioaccumulation or toxicity risk? Anderson et al. (2001) compared the hepatic concentrations of copper in largemouth bass (Micropterus salmo- TABLE 10.1 Costs of Copper Sulfate Treatments at Casitas Reservoir, California Treatment Cost (2002$) CuSO 4 solution $169–499 ha –1 ($19–202 acre –1 ) CuSO 4 crystals $152–913 ha –1 ($72–370 acre –1 ) CuSO 4 –citric acid solution $98–1106 ha –1 ($40–446 acre –1 ) Copper-ethanolamine granular $547–2263ha –1 ($221–916 acre –1 ) Source: Modified from AWWARF. 1987. Current Methodology for the Control of Algae in Surface Waters. Research Report. AWWA, Denver, CO. With permission. Copyright © 2005 by Taylor & Francis ides) and common carp (Cyprinus carpio) in Lake Mathews and Copper Basin Reservoir, both in California. Lake Mathews, a water supply reservoir, received more than 2000 tons of granular copper sulfate over a 20-year period. The lake retained 80% of the applied copper, mainly associated with oxidizable and carbonate-bound phases that could release copper under some chemical conditions (Haughey et al., 2000). Copper Basin Reservoir was untreated. Sediment copper in Lake Mathews averaged 290 mg Cu/kg dry weight; Copper Basin’s was 8 mg Cu/kg dry weight. Hepatic accumulation of copper was found in smaller bass (< 41 cm length) and in all carp in the treated lake, but there were no apparent effects of copper on these species, as estimated by condition factors. Copper in treated lake sediments was found in organic, carbonate, and iron-oxide forms, with a small amount in bioavailable form. Toxicity bioassays, using amphipods (Hyallela azecta) and cattails (Typha latifolia), did not reveal impaired survival or growth when these species were exposed to re-wetted pond soils that had an average concentration of 173 mg Cu/kg dry weight (vs. 36 mg Cu/kg dry weight in untreated sediments) (Han et al., 2001). Accumulation in fish may be through food web transfer, or through direct exposure during applications. Copper may be highly toxic to benthic invertebrates (Giudici et al., 1988; Harrison et al., 1984; Mastin and Rodgers, 2000; Nor, 1987), but it does not appear to continue to interact with the water column after its deposition, at least in sediments with high carbonate content (Sanchez and Lee, 1978). Copper accumulation in sediments could produce a sufficiently high concentration to delay or greatly increase the costs of a sediment removal project, but sediment contamination has not been shown to impair certain fish, invertebrate, or vascular plant species. Copper could become a problem in low alkalinity lakes and reservoirs, with low carbonate- containing sediments, if acidification of the system occurred, perhaps through acid precipitation. For example, in laboratory tests, copper was toxic to fathead minnows (Pimephelas promelas) at concentrations as low as 2 μg Cu/L at pH 5.6 and dissolved organic carbon (DOC) of 20 μg/L. A multiple regression model found that pH and DOC explained 93% of the variance in toxicity in test systems (Welsh et al., 1993). Similar results occurred with Ceriodaphnia dubia (Cladocera) where the copper LC 50 increased (toxicity decreased) in direct proportion to pH and DOC increases (Kim et al., 2001). Prolonged use of copper to control algae could create a situation where an acidified lake or reservoir was rendered unusable. Copper algicides should not be used in low pH, low DOC, poorly buffered waters. The potential for copper toxicity in contaminated sediments can be predicted by pore water concentration, or by acid-volatile sulfide (AVS) concentration. AVS binds with metals, mole for mole, to form an insoluble metal complex. Thus, if AVS concentration in sediments exceeds the concentration of a simultaneously extracted metal (SEM), all of the metal exists as a sulfide (e.g., CuS) and cannot be directly toxic to benthos (Ankley et al., 1996). However, as these authors note, resuspended sediments, or contamination of food webs via ingestion of contaminated benthos, detritus, or sediments, may produce toxicity that cannot be predicted from the AVS/SEM analysis. This predictive analytical tool should be useful where there are concerns about copper toxicity of lake sediments following extensive CuSO 4 applications. The “rebound” of algal biomass after CuSO 4 treatment may be from copper toxicity to algae- grazing zooplankton (McKnight, 1981; Cooke and Carlson, 1989). CuSO 4 is highly toxic to species of Daphnia, a common and effective grazer of planktonic algae, and an important item in fish diets (Chapter 9). Copper concentrations 100 times less than needed for algae control inhibit reproduction or are lethal to zooplankton (Blaylock et al., 1985; Naqvi et al., 1985; Winner et al., 1990). Daphnia magna, D. pulex, D. parvula, and D. ambigua, tested in waters with an alkalinity of 100–119 mg/L as CaCO 3, exhibited reductions in survival and reproduction when copper concentrations exceeded 8 μg Cu/L (Winner and Farrell, 1976). The 48-h LC 50 for D. magna exposed to the complexed products Clearigate and Cutrine-Plus (Applied Biochemists Inc., Milwaukee, Wisconsin), and to granular CuSO 4 , were 29, 11, and 19 μg Cu/L, respectively. Alkalinity in these test systems ranged from 55–95 mg/L as CaCO 3 at pH 7–8 (Mastin and Rodgers, 2000). These concentrations are more than an order of magnitude lower than recommended doses for lakes with moderate or high Copyright © 2005 by Taylor & Francis alkalinity. In many copper-treated waters, natural mortality of algae through grazing may be reduced or eliminated and a brief chemical-based mortality substituted, perhaps creating a “chemical dependency” on the part of lake users. The responses of lake communities to copper, or presumably to any toxicant, may be poorly estimated from single species laboratory studies. Taub et al. (1990) treated species-rich laboratory ecosystems with copper during different periods in ecological succession. Copper was an effective algicide early in succession but became less effective as pH and dissolved organic carbon increased over time from community metabolism. This study suggested that copper should be applied during the initial stages of an algal bloom before cells have altered the water’s chemical content sufficiently to limit copper toxicity, and when cells are actively dividing. Copper stress impairs food web functions. When planktonic communities in in situ mesocosms were exposed to 140 μg Cu/L for 14 days, not only were Daphnia, phytoplankton, and Protozoa (ciliates, flagellates) greatly reduced in abundance, but carbon flow through the food web was impaired. Bacteria increased significantly, but there was little energy transfer via the microbial loop to higher trophic levels (Havens, 1994). Fifty-eight years of granular CuSO 4 treatments of four Minnesota recreational lakes and a water supply reservoir may have produced significant deterioration of their quality. The deposition of dead organic matter in deeper water after a CuSO 4 application was large enough to stimulate microbial metabolism and eliminate DO. Low or zero DO conditions apparently stimulated P release from enriched sediments, which in turn stimulated algal blooms, requiring yet another algicide application. A state regulatory agency terminated CuSO 4 use in all of these systems due to copper contamination of sediment. Phytoplankton problems did not become worse (Hanson and Stefan, 1984). Copper does not appear to be directly teratogenic, mutagenic, or carcinogenic to humans. Unlike aquatic organisms, humans tolerate moderately high concentrations (< 1.5 mg Cu/L) (Nor, 1987). However, the use of CuSO 4 to control cyanobacteria blooms in potable water supply lakes and reservoirs poses a potential human health risk. Cyanobacteria, especially species of Microcystis, Anabaena, and Anabaenopsis (Cylindrospermopsis) may produce powerful hepatotoxins and neu- rotoxins. Consumption of raw water (prior to appropriate potable water treatment) has been asso- ciated with livestock and human illnesses and deaths (Carmichael et al., 1985, 2001). When copper is used to treat the reservoir, cell lysis occurs, releasing toxins (Kenefick et al., 1992). In northern Queensland, Australia, 148 people, mostly children, were affected with hepatoenteritis. Most were hospitalized. An epidemiologic study found that only people who had consumed water from Soloman Dam, which had been copper-treated several days earlier, had become ill. The source of the toxin was Cylindrospermopsis raciborskii (Bourke et al., 1983; Hawkins et al., 1985). Most modern water supply treatment plants that treat eutrophic raw water use granular activated carbon (GAC) to remove dissolved organic compounds. GAC may remove algal toxins as well. However, some plants process copper-treated eutrophic raw water without GAC. Unless the operators are aware of a potentially toxic cyanobacteria bloom, and take appropriate steps, toxin-laden water could be sent into the distribution system. Drinking water supply managers should monitor algal species composition and density on a daily basis, at sites along the reservoir’s length (Cooke and Carlson, 1989) in order to anticipate an algal bloom. Cyanobacteria blooms may originate in the riverine zone, or be inoculated from sediments and develop in the water column (Barbiero and Kann, 1994). In either case, early and regular algicide treatment may prevent the bloom from materializing. But even this “early warning system” (Means and McGuire, 1986) can fail to prevent the bloom. 10.6 COSTS OF COPPER SULFATE The costs for CuSO 4 use in algae management are dictated by dose, frequency of reapplication, area to be treated, type of algal nuisance, and other lake-specific factors. The more costly chelated or complexed forms may be needed in hardwater situations, but may be longer lasting and more effective. Copyright © 2005 by Taylor & Francis In four Minnesota recreational lakes and a water supply lake, with over 58 years of CuSO 4 treatment, 1.5 million kg of CuSO 4 were applied at an estimated cost of $4.04 million (2002 U.S. dollars), including labor and operating costs. During summer months, 35% of the chemical costs at the water treatment plant were for CuSO 4 . Costs for chemicals to operate the plant have not increased since terminating CuSO 4 applications. The treatments were not sufficiently cost effective, given that benefits were temporary and there were long-term environmental changes (Hanson and Stefan, 1984). The variation of single treatment costs with copper formulation is illustrated by the treatments at Casitas Reservoir, California (Table 10.1). Granular copper sulfate costs about $2.00 per kilogram, and liquid Cutrine Plus costs about $10.00 per liter (McComas, 2003). Application costs vary greatly. Copper sulfate application, the standard treatment for algal problems for many decades, is often effective for brief periods and may be the only short-term solution to a current algae problem, particularly in water supply reservoirs. However, there is substantial evidence against the continued use of this compound, in part from the low or non-existent margin of safety for non-target organisms. There are other longer term and more permanent options, including control of external and internal nutrient loading, to manage algae. Water supply operators should exercise caution in using copper sulfate, particularly during algal blooms, and should develop a diagnosis-feasibility and manage- ment plan to address causes of algal blooms (Cooke and Carlson, 1989; Chapter 3). REFERENCES American Water Works Association Research Foundation (AWWARF). 1987. Current Methodology for the Control of Algae in Surface Waters. Research Report. AWWA, Denver, CO. Anderson, M.A., M.S. Giusti and W.D. Taylor. 2001. Hepatic copper concentrations and condition factors of largemouth bass (Micropterus salmoides) and common carp (Cyprinus carpio) from copper sulfate- treated and untreated reservoirs. Lake and Reservoir Manage. 17: 97–104 Ankley, G.T., D.M. DiToro, D.J. Hansen and W.J. Berry. 1996. Technical basis and proposal for deriving sediment quality criteria for metals. Environ. Toxicol. Chem. 15: 2056–2066. Barbiero, R.P. and J. Kann. 1994. The importance of benthic recruitment to the population development of Aphanizomenon flos-aquae and internal loading in a shallow lake. J. Plankton Res. 16: 1581–1588. Bean, E.L. 1957. Taste and odor control at Philadelphia, J. Am. Water Works Assoc. 49:205–216. Benoit, R.A. 1975. Chronic effects of copper on survival, growth, and reproduction of the bluegill (Lepomis macrochirus). Trans. Am. Fish. Soc. 104: 353–358. Blaylock, B.G., M.L. Frank and J.F. McCarthy. 1985. Comparative toxicology of copper and acridine to fish, Daphnia, and algae. Environ. Toxicol. Chem. 4: 63–71. Bourke, A.T.C., R.B. Hawes, A. Neilson and N.D. Stallman. 1983. An outbreak of hepato enteritis (the Palm Island mystery disease) possibly caused by algal intoxication. Toxicon 3 (suppl.): 45–48. Button, K.S., H.P. Hostetter and D.M. Mair. 1977. Copper dispersal in a water supply reservoir. Wat er Res. 11: 539–544. Carmichael, W.W., C.L.A. Jones, N.A. Mahmood and W.C. Theiss. 1985. Algal toxins and water-based diseases. CRC Rev. Environ. Control 15: 275–313. Carmichael, W.W., S.M.F.O. Azevedo, J.S. An, R.J.R. Molica, E.M. Jochimsen, S. Lau, K.L. Rinehart, G.R. Shaw and G.K. Eaglesham. 2001. Human fatalities from Cyanobacteria: Chemical and biological evidence for cyanotoxins. Environ. Health Perspect. 109: 663–668. Cooke, G.D. and R.E. Carlson. 1989. Reservoir Management for Water Quality and THM Precursor Control. American Water Works Association Research Foundation (AWWARF). Denver, CO. Demayo, A., M.C. Taylor and K.W. Taylor. 1982. Effects of copper on humans, laboratory and farm animals, terrestrial plants, and aquatic life. CRC Rev. Environ. Control 12: 183–255. DuBose, C.K. Langeland and E. Philips. 1997. Problem fresh water algae and their control in Florida. Aquatics 19: 4–11. Copyright © 2005 by Taylor & Francis Elder, J.F. and A.J. Horne. 1978. Copper cycles and CuSO 4 algicidal activity in two California lakes. Environ. Manage. 2: 17–30. Ellgaard, E.G. and J.L. Guillot. 1988. Kinetic analysis of the swimming behavior of bluegill sunfish, Lepomis macrochirus Rafinesque, exposed to copper: Hypoactivity induced by sublethal concentrations. J. Fish. Biol. 33: 601–608. Erickson, R.J., D.A. Benoit, V.R. Mattson, H.P. Nelson Jr. and E.N. Leonard. 1996. The effects of water chemistry on the toxicity of copper to fathead minnows. Environ. Toxicol. Chem. 15: 181–193, Fitzgerald, G.P. 1967. Current methods for algae control. IN: Proceedings Fourth Annual Water Quality Research Symposium. New York State Department of Health, Albany, NY. pp. 72–81. Fitzgerald, G.P. 1981. Selective algicides. In: Proceedings of Workshop on Algal Management and Control. Tech. Rept. E-81-7. U.S. Army Corps of Engineers, Vicksburg, MS. pp. 15–31. Giudici, M.D., L. Migliore, C. Gambardella and A. Marotta. 1988. Effect of chronic exposure to cadmium and copper on Asellus aquaticus (L.) (Crustacea, Isoposa). Hydrobiologia 157: 265–269. Han, F.X., J.A. Hargreaves, W.L. Kingery, D.B. Huggett and D.K. Schlenk. 2001. Accumulation, distribution, and toxicity of copper in sediments of catfish ponds receiving periodic copper sulfate applications. J. Environ. Qual. 30: 912–919. Hanson, M.J. and H.G. Stefan. 1984. Side effects of 58 years of copper sulfate treatment of the Fairmont Lakes, Minnesota. Water Res. Bull. 20: 889–900. Harrison, F.L., J.P. Knazovich and D.W. Rice. 1984. The toxicity of copper to the adult and early life stages of the fresh water clam, Corbicula manilensis. Arch. Environ. Toxicol. Chem. 13: 85–92. Haughey, M.A., M.A. Anderson, R.D. Whitney, W.D. Taylor and R.F.Losee. 2000. Forms and fate of Cu in a source drinking water reservoir following CuSO 4 treatment. Water Res. 34: 3440–3452. Havens, K.E. 1994. Structural and functional responses of a fresh water plankton community to acute copper stress. Environ. Pollut. 86: 259–266. Hawkins, P.R., M.T.C. Runnegar, A.R.B. Jackson and I.R. Falconer. 1985. Severe hepatotoxicity caused by the tropical cyanobacterium (blue-green alga) Cylindrospermopsis raciborskii (Woloszynska) Seenaya and Subba isolated from a domestic water supply reservoir. Appl. Environ. Microbiol. 50: 1292–1295. Horne, A.J. and C.R. Goldman. 1974. Suppression of nitrogen fixation by blue-green algae in a eutrophic lake with trace additions of copper. Science 83: 409–411. Kenefick, S.L., S.E. Hrudey, H.G. Peterson and E.E. Prepas. 1992. Toxin release from Microcystis aeruginosa after chemical treatment. Water Sci. Technol. 27: 433–440. Kim, S.D., M.B. Gu, H.E. Allen and D.K. Cha. 2001. Physicochemical factors affecting the sensitivity of Ceriodaphnia dubia to copper. Environ. Monitor. Assess. 70: 105–116. Lembi, C.A. 2000. Relative tolerance of mat-forming algae to copper. J. Aquatic Plant Manage. 38: 68–70. Mackenthun, K.M. 1961. The practical use of present algicides and modern trends toward new ones. In: Algae and Metropolitan Wastes. Trans. of 1960 Seminar, U.S. Dept. Health, Education, and Welfare, U.S. Public Health Service. PB-199-296. Cincinnati, OH. pp. 148–154. (Note: this article contains the original dose chart and design specifications for copper sulfate applications.) Mastin, B.J. and J.H. Rodgers, Jr. 2000. Toxicity and bioavailability of copper herbicides (Clearigate, Cutrine- Plus, and copper sulfate) to fresh water animals. Arch. Environ. Contam. Toxicol. 39: 445–451. McComas, S. 2003. Lake and Pond Management. Lewis Publishers and CRC Press, Boca Raton, FL. McGuire, M.J., R.M. Jones, E.G. Means, G. Izaguirre and A.E. Preston. 1984. Controlling attached blue-green algae with copper sulfate. J. Am. Water Works Assoc. 76: 60–65. McKnight, D. 1981. Chemical and biological processes controlling the response of a fresh water ecosystem to copper stress: a field study of the CuSO 4 treatment of Mill Pond Reservoir, Burlington, Massachu- setts. Limnol. Oceanogr. 26: 518–531. McKnight, D.M., S.W. Chisholm and F.M.M. Morel. 1981. Copper Sulfate Treatment of Lakes and Reservoirs: Chemical and Biological Considerations. Tech. Note No. 24. Dept. Civil Eng., Massachusetts Institute of Technology, Cambridge, MA. McKnight, D.M., S.W. Chisholm and D.R.F. Harleman. 1983. CuSO 4 treatment of nuisance algal blooms in drinking water reservoirs. Environ. Manage. 7: 311–320. Means, E.G. III and M.J. McGuire 1986. An early warning system for taste and odor control. JAm. Water Works Assoc. 78(3): 77–83. Minnesota Department of Natural Resources. Control of Swimmers’ Itch and Leeches. Undated informational leaflet #8. Ecological Services Division, Division of Fish and Wildlife, Minneapolis. Copyright © 2005 by Taylor & Francis Naqvi, S.N., V.D. Davis and R.M. Hawkins. 1985. Percent mortalities and LC 50 values for selected micro- crustaceans exposed to Treflan, Cutrine-Plus, and MSMA herbicides. Bull. Environ. Contam. Toxicol. 35: 127–132. Nor, Y.M. 1987. Ecotoxicity of copper to biota: a review. Environ. Res. 43: 274–282. Raman, R.K. and Cook, B.C. 1988. Guidelines for Applying Copper Sulfate as an Algicide: Lake Loami Field Study. ILENR/RD-WR-88/19. Illinois Dept. Energy Natural Resources, Springfield, 9 pp. Sanchez, I. and Lee, G.F. 1978. Environmental chemistry of copper in Lake Monona, Wisconsin. Water Res. 12: 899–903. Sandheinrich, M.B. and G.J. Atchison. 1989. Sublethal copper effects on bluegill, Lepomis macrochirus, foraging behavior. Can. J. Fish. Aquatic Sci. 46:1977–1985. Taub, F.B., A.C. Kindig, J.P. Meador and G.L. Swartzman. 1990. Effects of “seasonal succession” and grazing on copper toxicity in aquatic microcosms. Verh. Int . Vere in. Limnol. 24: 2205–2214. Twiss, M.R., P.M. Welbourn and E. Schwartzel. 1993. Laboratory selection for copper tolerance in Scenedes- mus acutus (Chlorophyceae). Can. J. Bot. 71: 333–338. Welsh, P.G., J.F. Skidmore, D.J. Spry, D.G.Dixon, P.V. Hodson, N.J. Hutchinson and B.E. Hickie. 1993. Effect of pH and dissolved organic carbon on the toxicity of copper to larval fathead minnow (Pimelphales promelas) in natural lake waters of low alkalinity. Can. J. Fish. Aquatic Sci. 50: 1356–1362. Winner, R.W. and M.P. Farrell. 1976. Acute and chronic toxicity of copper to four species of Daphnia. J. Fish. Res. Bd. Canada 33: 1685–1691. Winner, R.W., H.A. Owen and M.V. Moore. 1990. Seasonal variability in the sensitivity of fresh water lentic communities to a chronic copper stress. Aquatic Toxicol. 17: 75–92. Copyright © 2005 by Taylor & Francis . lakes with high alkalinity and pH (Figures 10. 1 and 10. 2). Copper is less toxic in hard water, in part due to the precipitation of malachite (Cu(OH) 2 CO 3 ) and to competition with calcium and. these concentra- tions will be toxic to many species of algae and to some non-target organisms (Nor, 1987). Control of Chara and Nitella requires a dose of 1.5 mg/L, or higher, and must be applied. tank mixes of herbicides to enhance macrophyte control (Chapter 16). The purposes of this chapter are to describe copper sulfate’s dose and application procedures, and to discuss its positive and negative