On Tap: Industrial Waste Risk and Management in Drinking Water Sources
by Dr. Kelly A. Reynolds
Industrial waste production is a reality of life. Management of waste discharges from manufacturing, agriculture and other processes involves making a series of decisions influenced by the level of known, or perceived, risks and best practice approaches. In 1972, the Clean Water Act (CWA) was implemented by the US EPA to control pollutant discharges from point sources into navigable waters. Discharge levels are now controlled by the National Pollutant Discharge Elimination System (NPDES) permit program, which is designed to limit contaminant levels in water to below admissible standards. While these regulations and related programs have dramatically improved the tracking and management of industrial waste pollution, many data gaps have been identified, leading to uncertainty in exposure and risk assessments. POU drinking water treatment provides one of the few options where individuals can exercise control over potentially harmful pollutant exposures.
A transparent problem
Information on toxic environmental releases is publicly available on the US EPA website and easily searched by geographical areas of interest(1). The Hazardous Waste Report, published biennially, provides information on large-quantity generators of hazardous waste and treatment, storage and disposal practices. Information from ongoing or old cleanup sites from areas of accidental spills or leaks can also be found in brownfields and superfund site databases. Hazardous waste information is kept in the national Resource Conservation and Recovery Act Information (RCRAInfo) inventory system as hazards are tracked from generation to transportation, treatment storage and eventual disposal.
Perusing these databases for national status and trends reveals one main fact: there is no shortage of transparency. The Toxic Substances Control Act (TSCA) requires US EPA to keep a list of chemicals manufactured or processed in the US. The initial TSCA Inventory was published in 1979 and soon amassed 62,000 chemical substances. Seemingly endless amounts of data are available on the use and disposal of chemicals. Currently, over 84,000 chemical substances are on the list with safety assessments available for around 200.
The Toxic Release Inventory (TRI) keeps track of over 600 compounds that are known human health or environmental threats. Industries must report the amount of these toxic compounds that were released into the environment, either to air, water or land. Program advocates claim that the transparency of the program drives industries toward more responsible management of hazardous agent disposal. Seemingly endless amounts of data are available on the use and disposal of chemicals. Not all toxic compounds, however, are listed in the TRI. The magnitude of the data gap causes unrest among many stakeholders.
Compliance and criticism
The Clean Water Act mandates that states and territories report when waters do not meet their designated use (i.e., for drinking, fishing or swimming). The act further requires that identified sites be ranked for assessment of how much pollutant can be discharged for the waterway to still meet regulatory standards of quality. This value is known as the total maximum daily load (TMDL). Over the last 20 years, approximately 65,000 TMDLs have been developed but the number of impaired waters remains staggering.
Many states list thousands of impaired waterways. Pathogens, nutrients, metals, eutrophication, sediment, PCBs and mercury are the top causes of water impairment but the list of other causes is long and varied. Concerning events range from leaking underground storage tanks or toxic spills to consumer or commercial use of pesticides, fertilizers and petroleum products. Searching the quality of your own local waterways is easy via the US EPA How’s my Waterway? site, but how to translate that information into public health benefits is less obvious(2).
While federal standards provide a legal framework for compliance and consequences, criticism over relatively small and loosely applied enforcement is common among accusations of worsening water quality (3). Officials responded by pointing out that, “much of the country’s water quality problems are caused by discharges from non-point sources of pollution, such as agri- cultural runoff and storm water flows, which cannot be corrected solely through enforcement.” Unlike point-source pollutants that originate from a single site, such as an industry discharge point, non-point sources are largely unregulated.
In 2009, US EPA initiated efforts to strengthen the US chemical management laws while developing new regulatory risk management actions for particular pollutants, such as lead, formaldehyde and nanoparticles. Under scrutiny of inactivity following the 1972 promulgation of the Clean Water Act, the agency further announced efforts to develop action plans for 10 chemicals and gather information where gaps existed in chemical risk assessment (4). Increasing public access to information about chemicals and environmental monitoring and contamination evidence was a big part of the targeted expansion as well. By 2012, US EPA identified 83 chemicals for detailed assessment and created a plan to assess additional chemicals each year. Priority was given to chemicals that were potentially harmful to children, causing reproductive or developmental effects, or used in children’s products. In addition, those known or suspected of causing cancer or neurotoxic effects and thought to persist in the environment and bio-accumulate were of primary concern.
Most recently, the 2014 list of chemicals slated for some type of action (i.e., regulatory action to label, restrict or ban a chemical, or to require additional data for risk determination) included: Bisphenol A (BPA), Decabromodiphenyl ether (decaBDE), Hexabromocyclododecane (HBCD), Nonylphenols and nonylphenol ethoxylates (NP/NPE) and a variety of phthalates (dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DnOP), di-isononyl phthalate (DINP), di-isodecyl phthalate (DIDP) and di-isobutyl phthalate (DIBP). Various legislators recently proposed more stringent laws for chemical safety assessments, placing increasing responsibility on manufacturers for risk assessment and management, but these were not enacted. Critics of increased legislation point out that existing laws are sufficient but poorly enforced.
Assessment of waterways as a potential source of drinking water involves a series of steps that include: 1) determine the source and flow of water and possible pollutants mapped from the region; 2) develop an inventory of possible contamination sources, such as landfills, septic systems, farming operations, mining and other industries and 3) determine the susceptibility of the supply with identified contamination sources. The latter step sometimes involves a susceptibility ranking of the water source. These assessments provide key information for developing use and protection limits in the community but offer little in terms of personal risk. With so many chemicals in use and so many applications, combined uses and sometimes subtle health effects, understanding the long-term impacts of chemical exposures in the environment is extremely complex. Despite great regulatory advances since the passing of the Clean Water Act and other laws, evaluation and regulation of environmental contaminants is a slow and tedious process.
Pollutants discharged into the environment reach vulnerable populations via contaminated food, air and water routes. Perhaps one of the easiest points of personal control is the waterborne route. Despite varied forms of contaminants (organic, inorganic, radioactive, microbial), POU devices can dramatically reduce exposures, resulting in reduced human health risks. Broad spectrum, multi-barrier technologies are available to address multiple, emerging and unknown hazards simultaneously.
1. US EPA, Envirofacts: topic searches, US EPA, [Online]. Available: www.epa.gov/enviro/facts/topicsearch.html. [Accessed 10 March 2015].
2. US EPA, How’s my waterway? [Online]. Available: watersgeo.epa.gov/ mywaterway. [Accessed 10 March 2015].
3. “Clean water laws neglected, at a cost,” The New York Times, p. A1, 12 September 2009.
4. US EPA, Enhancing EPA’s Chemical Management Program, US EPA, 8 January 15. [Online]. Available: www.epa.gov/oppt/existingchemicals/ pubs/enhanchems.html. [Accessed 10 March 2015].