Water Worlds: A look at hot issues within the treatment process

When we open up our faucet and let water pour out, we’re engaging in the miracle of modern plumbing that began hundreds of years ago and today remains a staple of civilization.

For Darienites connected to the public water supply, the process of bringing water from its source and to homes and businesses involves numerous treatment steps, ensuring the water meets federal drinking water standards as outlined in the Clean Water Act.

This week, The Darien Times examines some of the more controversial elements of water treatment, such as chemical additives and sediment disposal.

Fluoridation

When the U.S. began adding fluoride to water in the 1950s, opposition to the process came mostly from extreme right wing conspiracy theorists who saw it as an act perpetrated by communists seeking to gain control over American minds.

But it wasn’t until the 1990s that public water fluoridation affected the majority of American homes, according to award-winning science writer Robin Marantz Henig, whose 1997 book “The People’s Health” examines the evolution of public health policy and its global implications.

These days, opposition to fluoridation has expanded to include scientists, researchers and others concerned about what some have called an act of mass medication. The U.S. is one of only a handful of countries still adding fluoride to public water. It’s banned in continental Europe, although fluoride is added to table salt there.

Connecticut public water standards require companies to add fluoride to water when a population exceeds 20,000. Aquarion, which produces and distributes water to Darien residents connected to the public system, complies with this statute. As per state law, fluoride levels are to stay between 0.8 and 1.2 milligrams per liter.

Darien water averaged 0.94 mg/L of fluoride during 2011, according to Aquarion data, and tested between 0.61 and 1.12 mg/L throughout the year. The Environmental Protection Agency, or EPA, set the maximum contaminant level of fluoride at 4 mg/L, which means that levels above that are expected to have adverse health effects.

However, opponents argue that even lower levels of water fluoridation could potentially cause problems, and that the positive effects of fluoridation, such as a decrease in dental cavities, could be attributable to other factors.

Researchers at the University of Palermo’s Department of Oral Sciences concluded in 2007 that adding fluoride to water “plays a limited role” in preventing cavities, and that fluoridation “may be unnecessary” to prevent cavities, the study continued, “particularly in the industrialized countries…”

This sentiment has some history. In 1986, a commentary in the scientific journal Nature by Australian scientist Dr. Mark Diesendorf noted that “large temporal reductions in tooth decay, which cannot be attributed to fluoridation, have been observed in both unfluoridated and fluoridated areas of at least eight developed countries.”

However, the Centers for Disease Control listed public water fluoridation as its ninth most important public health measure of the 20th Century, just ahead of recognizing tobacco as a health hazard and behind family planning. The American Dental Association and the World Health Organization agree that fluoridation is successful at reducing cavities.

“Research shows that drinking optimally fluoridated water is one of the safest and most cost-effective public health measures for preventing, controlling, and in some cases reversing, tooth decay,” states the dental association on its website.

Even proponents of fluoridation acknowledge that it can lead to dental fluorosis, a condition where teeth appear brown that affects mostly children. This ailment is considered by many to be merely cosmetic, however, and not a serious health issue.

Opponents argue that people with kidney disease and children are most at risk by adding fluoride to water. A 2006 study conducted by the National Research Council suggested that “even at concentrations below 1.2 mg/L in drinking water, over the years can increase the risk for renal calculi (kidney stones).”

“Several investigators have shown that patients with impaired renal function, or on hemodialysis, tend to accumulate fluoride much more quickly than normal,” the study continued. “Extreme caution should be used in patients on hemodialysis because failures of the dialysis equipment have occurred in the past, resulting in fluoride intoxication.”

In addition to hydrofluorosilicic acid (the fluoride type that Aquarion uses), the EPA allows public water suppliers to treat water with more than 108 chemicals, ranging from sulfuric and hydrochloric acids to adjust pH levels, to starch, lye, bleach, baking soda and hydrogen peroxide.

The non-profit NSF (National Sanitation Foundation) International developed guidelines for the EPA in 1988 regarding what types of chemicals can be used for water treatment and the maximum concentrations to avoid negative health risks, according to Greg Kail, communication director for the American Water Works Association, a nonprofit concerned with global water quality. NSF International operates in 150 countries and employs roughly 1,200 people, and companies pay NSF for product certification that is often required by law.

Residuals

When naturally occurring water, or raw water as it’s known in the treatment industry, first enters a treatment facility, the organic matter first needs to be discarded. This is done by either adding a coagulant to give the particles weight so they can sink, or by injecting pressurized air into the water to float the particles to the top.

These particles are known as residual solids and must be disposed of. At Aquarion’s Easton facility, the solids are dried in a lagoon and after a year, Aquarion pays for the solids to be removed and pays for them to be received by Scotts MiracleGro to be used in soil that is then resold to the general public.

Mike Liberante, manager of treatment at Aquarion’s Easton facility, told The Times that he estimates the plant disposes of between 300 and 500 tons of residuals annually. Peter Fazekas, a public relations manager for the company, declined to comment on how much Aquarion pays Scotts to take the residuals.

Liberante said the residuals are used in the Earthgro brand soil. The Darien Times examined reviews of Earthgro Potting Soil online and found that four out of six purported customers rated it one star out of five, claiming everything from the soil looking like clay, smelling like manure or urine, to being infested with gnats. Another soil, Earthgro Topsoil, received not a single positive review. All four complaints gave the product one out of five stars, with problems ranging from bad soil consistency to it smelling like chemicals.

Keri Butler, a spokesman for Scotts, told The Times that her company uses residuals from Aquarion for a number of soils, including the popular MiracleGro brand.

“We have pretty stringent soil standards,” Butler said, adding that soil contains bacteria naturally, which can contribute to foul smelling batches of dirt.

Chlorine bleach and aluminum sulfate can end up in the dirt that Scotts gets paid to take. By this point, some of the aluminum sulfate has become aluminum hydroxide, which is found in nature as the mineral gibbsite. Aluminum sulfate is also often used to reduce the pH of gardens.

Chlorine, however, has little benefit to soil and plant health, although chlorine levels in soil taken by Scotts falls within EPA and state Department of Health standards, Butler added.

“We get organic and natural materials form a variety of sources,” Butler said. “It could be bark or wine skins — we are keeping it out of the landfill. The story for us is, it’s really an environmentally friendly practice.”

Darien water comes mostly from the Stamford treatment facility. Here, there are no drying lagoons, so the Stamford plant transfers the solids to its wastewater treatment facility where it mingles with water at the end of the human-use cycle, according to Fazekas of Aquarion.

Stamford then treats the residual solids with human sludge and creates a product known as biosolids. Biosolids are treated municipal sewage approved for use as fertilizer on farms. Stamford pays the company Synagro to dispose of its biosolids, and Synagro then sells the biosolids in pellet form for use in upstate New York.

These biosolids are classified as Class A, meaning it can be applied similarly to other fertilizers, except it can’t be used on products for direct human consumption. There is no law against consuming products in a secondary fashion, such as eating meat from an animal that was fed on crops grown in biosolids.

In 2011, New York received 2,000 tons of biosolids from Stamford, which was used on five upstate farms in Moravia, Kings Ferry, Walden, Gushen and Jamesport, said Charsleissa King, a spokesman for the state’s Department of Environmental Conservation.

The EPA requires wastewater treatment facilities test for 10 heavy metals, nine inorganic chemicals and a few strains of microorganisms. Before being certified for land application for use as biosolids, the sludge is treated through either aerobic or anaerobic digestion and/or lime stabilization.

Critics contend that the EPA needs to learn more about biosolids before its use is allowed to continue. In 2009, the EPA tested for 145 contaminants in 74 randomly chosen wastewater treatment facilities in 35 states, with the results revealing an assortment of steroids, hormones, flame retardants, pesticides, plasticizers, pharmaceuticals, semivolatile organics and polycyclic aromatic hydrocarbons in the biosolids.

Other methods for eliminating solid waste and water treatment residuals include landfilling and burning to generate electricity. Each process has its own advantages and disadvantages.

Originally published in The Darien Times.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s