A few weeks ago there was an article (and a letter) in the Herald-Sun newspaper (www.herald-sun.com) on upgrades to the Triangle Wastewater Treatment Plant to produce cleaner effluent to improve Jordan Lake's waster quality. The Triangle WTP is at the intersection of TW Alexander Drive and Highway 55 in Durham County and dumps into Northeast Creek.
The improvements are good, for example the Creek no longer smells like chlorine for miles. More should be done. This treated water might still degrade the Creek's ecosystem and this dumping therefore violates the spirit of the Clean Water Act (see the article below). Also, these improvements are being made to improve Jordan Lake, not for the sake of cleaner water in general, which I think should be the goal.
Jordan Lake has its good points but it destroyed a huge area of bottomlands that were probably rich in wildlife, as well as destroying a small town. I am irritated that the concern is for its water quality, not for the quality of the natural waterways running into it. Jordan Lake provides recreation and drinking water, but the creeks also provide recreation and food for people, as well as being diverse habitats for wildlife.
I am planning to start a Stream Watch group (part of a State program) for Northeast Creek to help improve and safeguard its quality and diversity.
I wrote the article below in October 2003 for UNC-Chapel Hill's left student magazine, Boiling Point.
Are wastewater treatment plants harming the quality of local waterways?
Where the entrance ford into UNC’s Mason Farm Biological Preserve crosses Morgan Creek there is a ‘chlorine’ smell to the air, but, other than perhaps its constant flow, the Creek seems ordinary. If you walk upstream to the area behind Finley Golf Course’s parking lot you will find the Orange Water and Sewer Authority’s Mason Farm Wastewater Treatment Plant discharging processed wastewater into Morgan Creek.
In this age of environmental concern, sewage treatment plants are often the only point-source (pollution sources at a particular point, such as a pipe) polluters of local waterways. Treating wastewater before releasing it into the wild was a great improvement and has resurrected many waterways but today they are a main source of pollution. Their design and location in flood-prone bottomlands shows a disregard for improving water quality. Wastewater treatment plants (WTPs) only have to treat water to match the use of the waterway they drain into, preventing improvements. They release man-made and possibly harmful chemicals from the process of water treatment and chemical that were not removed, depending on the design of the plant they can release biocidal amounts of chlorine compounds into natural waterways, they release disease-causing pathogens, especially during floods, and they release biologically significant quantities of medical and possibly illegal drugs into the water. These problems are worsened by their often being located in flood-prone bottomlands, out of sight and without levees. Local creeks should not be mere ways to carry polluted water out of sight and out of mind. The Clean Water Act of 1972, a landmark law regulating pollution and water treatment, broadly defines the pollution it is intended to prevent as “the man-made or man-induced alteration of the chemical, physical, biologically, and radiologically integrity of water” (Adler, 1993) and if the effluent of local WTP’s is reducing water quality, then it has not met these expectations. Neither have they met the goal of zero-discharge in 1980s.
Heavy metals are toxic because above a certain quantity they hinder vital enzymes, disrupting bodily processes. Copper, lead, and zinc are leached from water system pipes and may be released with treated water in waterways, although heavy metals tend to accumulate in sludge rather than in the released water. These three metals are more toxic than many other heavy metals and they are not strongly stored in bottom sediment in waterways (Kennish, 1992). The concentration of heavy metals is of less concern than how they are complexed into molecules in a specific environment. Under the Clean Water Act, WTPs receiving water from residential and industrial sources are classified as receiving only residential wastes and they might not be designed to treat industrial wastes they receive, not to say that residential waste always lacks heavy metals, etc (Adler, 1993). Hopefully OWASA’s plants are designed to fully treat UNC’s wastes.
WTPs do not produce completely clean water and nature is used to purify the discharged water, which obviously must contain chlorine compounds poisonous to aquatic organisms, and other substances. In fish chlorine enters their gills, and often damages the gill surfaces, but in the bloodstream it binds to hemoglobin, causing suffocation (methemoglobinemia) (Kennish, 1992). Because chlorinated water is deadly to wildlife in waterways, the EPA issued guidelines on when it should be used in disinfection (and this probably applies to chloramines): it should be used only where its benefits are proven and specifically to protect public health, it should be used where protecting aquatic wildlife is not a concern, and where public health and conservation conflict, an alternative method should be used. Chlorine is toxic to fish at very low concentrations, and at these low concentrations control is difficult (Spellman, 1999). In waterways continuously exposed to chlorinated water, the total chlorine concentration should not be more than 0.01 milligrams/liter for tolerant organisms or 0.002 mg/L for most wildlife, and this is interpreted as making all chlorine release impermissible (Spellman, 1999). Combined chlorine compound concentrations in tapwater are usually 1-4 mg/L.
Recently Chapel Hill, Durham, and Hillsborough joined Raleigh and Cary in disinfecting drinking water with chloramines instead of using only chlorine. Chloramines are compounds of chlorine attached to a molecule made of nitrogen and hydrogen (NH2Cl is an example of a chloramine) and are created by the mixing of chlorine and ammonia at some point in water treatment. Because ammonia is abundant in wastewater, even if local WTPs use only chlorine in wastewater treatment, chloramines are created, as well as entering the system through tapwater. Chloramines are replacing chlorine because they don’t produce as much of the potentially carcinogenic disinfection byproducts trihalomethanes (THMs), they might improve tapwater’s odor and taste, because of liability worries regarding chlorine, and because chlorine may be prohibitively regulated. The problem is that chloramines can exist much longer than other chlorine molecules because they are less reactive with other molecules and they are poisonous to fish, reptiles, amphibians, corals and other wildlife. Unless natural processes react with chloramines to render them harmless they could exist in treated water for days, continuously dosing miles of a waterway with a biocidal compound. Where I grew up in southern Durham Northeast Creek smelled like chlorine for many miles downstream of the Triangle Wastewater Treatment Plant until a change was made at the plant. Unlike Morgan Creek, NE Creek has a silt problem and this allows one to see that during the summer clear WTP discharge makes up much of the Creek’s flow for a long distance.
Treated water can be dechlorinated but this has potential problems as well. Dechlorinating chlorine compounds releases the molecules associated with them allowing new, toxic or carcinogenic compounds to arise (White, 1999). Dechlorinating chloramines releases ammonia and nitrogen containing compounds also poisonous to fish.
Chlorine can form THM compounds with organic matter in water and these compounds are regulated in drinking water to be at no more than 0.10 mg/L. In treated wastewater chlorine is more likely to form chloramines because of the abundance of ammonia, but THMs are still possible (Bryant et. al, 1992). THMs, other disinfection byproducts, and even the water disinfectants themselves may cause cancer and other illnesses. Chlorine affects the thyroid and possibly the kidneys and can form other byproducts after it enters the body and “liver toxicity” is caused in lab animals by chloramines (Bryant, 2000). The use of water treatment chemicals has inherent dangers, for example if one ton of chlorine gas kept at a WTP escaped, it could endanger an area within a six mile radius of the release, but accidents are rare (Spellman, 1999).
An obvious danger from WTPs is pathogens in wastewater and spills of raw sewage is a problem for this reason. Diseases ranging from fungal ear or skin infection and relatively minor viral gastrointestinal illnesses to lethal illnesses like typhoid and cholera are caused by the 300 viral types, 100 bacteria species, fungi, a few protozoa, and nematode and annelid worms transmitted through wastewaters. Some, such as the virus causing polio and Giardida protozoans, can survive away from a host for a long period (years for polio viruses), so contamination would occur without very many sewage spills (Buzzi, 1992). Many disease causing organisms infect wildlife or are opportunistic pathogens and cause disease only because nutrient-rich wastewater encourages their growth and increases chances of infection. Amoeba that cause rare (and lethal) brain infections and exist in this area are an example. This excess nitrogen in treated water should also change waterway ecosystems, maybe encouraging non-native and destructive carp populations, since excess nutrients tend to encourage generalist species like carp over ecological specialist species. Nitrites can be produced with chloramines by nitrogen-metabolizing bacteria, which are harmful to humans and wildlife (Environmental Health Program, 1995). The release of pathogens is also a danger to wildlife since they may be susceptible to infection by these organisms.
Biologically significant and active concentrations of medical and possibly illegal drugs (and the chemicals used to create them) (Daughton) and other household chemicals survive passage through WTPs and are continuously released into nature. Pharmaceuticals and personal care products, such as drugs and fragrances, have been found in small concentrations in natural waters. Medical drugs especially are often designed to be active in very small doses so a low concentration is not necessarily a good sign. As an example, one used NuvaRing contraceptive could pollute 24 million liters of water with estrogen at a level active in fish (see Science News magazine of Jan. 25, volume 163, number 4). Many substances still have not been looked for in natural waterways and the possibility of dangers to humans is even murkier than environmental effects. The chemicals mentioned in this article could also interact in unknown ways to be more dangerous to wildlife. Chemicals could be released at small rates, but become a problem if they accumulate in sediment or bioaccumulate through storage in certain species (Beuhler, 1993).
WTPs are often located without very adequate protection in floodplains, along with their inflowing sewer pipes. The Triangle WTP and its sewer easements are located on the banks of Northeast Creek, and it is only a few feet above the Creek banks without levees and it has sewer spills during every major storm. The Mason Farm WTP is much better protected, which is a good thing given that it is located on a low island. WTPs are usually relatively isolated, for good reasons, but this makes public oversight more difficult.
Pollutants and pathogens released by WTPs intentionally or unintentionally damage the quality and health of waterway ecosystems and potentially human health. It is possible that illegal activity makes contamination worse than we know from official information. The Public Interest Research Group reports that most municipal and industrial WTPs in several Northern states have violated their pollution permit (Environmental Water Analysis, 2002). Those in charge of our WTPs should be as concerned about dialoguing with the public about environmental problems as they are regarding human health. When Durham switched to chloraminating drinking water it alerted water customers about the health aspect of chloramines but glossed over any environmental issues. Natural waterways should not be used to transport wastes away from sight and concern and WTPs should not be dumping into waterways at all. Contamination and alteration of natural waterways by WTPs ought to be studied and here UNC could work to fix these problems. Biology, chemistry, environmental studies, and other classes could study how the Mason Farm WTP effects Morgan Creek, for example. Better means to treat wastewater exist and ought to be more widely used. American infrastructure such as WTPs needs upgrading and repair but instead money is squandered blowing up foreign infrastructure. Just because wastewater is treated before being dumped does not mean that it is free of pollutants and poisons, especially those unlikely to cause a scene (like a burning or fishless river) and publicly embarrass the utility.
Cited:
Adler, Robert W., Landman, Jessica C., Cameron, Diana M. The Clean Water Act: 20 Years Later. Island Press: Washington, D.C., 1993.
Beuhler, Mark D. Proceedings: 1992 Water Quality Technology Conference: Part I – Sunday Seminars Through Session 3D: November 15-19, 1992: Toronto, Canada. Ed. American Water Works Association. 1993.
Bryant, Edward A., Fulton, George P., Budd, George C. Budd. Disinfection Alternatives for Safe Drinking Water. New York: Van Nostrand Reinhold, 1992.
Buzzi, Ruth Ann. Chemical Hazards at Water and Wastewater Treatment Plants. Chelsea, Mich.: Lewis Publishers, 1992.
Environmental Health Program. Chloramines, modified May 1996, [web site]. Accessed February 8, 2003. Available at http://216.239.39.100/Search?q=caule:mqmAAmuJJMiC;www.hc.-sc.gc.ca/ehp/ehd/catalogue/bch_pubs/dwgsup_doc/chlora.pdf+chloramines&hl=en@ie=UTF-8 or from http://www.hc.-sc..ca/ehp/ehd/catalogue/bch_pubs/dwgsup_doc/chlora.pdf. Created October 1995.
Kennish, Michael J. Ecology of Estuaries: Anthropogenic Effects. Boca Raton, Flor.: CRC Press, 1992.
Spellman, Frank R. Choosing Disinfection Alternatives for Water/Wastewater Treatment. Lancaster, Penn.: Technomic Publishing Co., Inc., 1999.
White, Geo. C. Handbook of Chlorination and Alternative Disinfectants., 4th ed., New York: John Wiley & Sons, Inc., 1999.
Daughton, Christian G. Various webpages about ppcps and illicit drugs in wastewater, created from about 2001-2003, [web sites]. Accessed September 29, 2003. Available linked to www.epa.gov/nerlesd1/chemistry/pharma/index.htm
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