In-Plant Water Quality: Change on Way for Industrial Providers of Potable Water
Industrial facilities, whether supplied by municipal sources or in-house treatment system, are likely to be directly affected by water-related rules changes in the very near future.
Industrial facilities, whether supplied by municipal sources or in-house treatment system, are likely to be directly affected by water-related rules changes in the very near future. For potable or safe water, these are happening at an unprecedented rate at these often smaller systems, both from a regulatory view and a treatment technology perspective. Keeping up can be a full-time job for those charged with potable and/or process water treatment at an industrial site. While the changes largely affect operations providing their own potable water, municipal rule changes can “trickle down” as well.
Regulations for facilities supplying their own water for both potable and process use have been growing at a rapid rate. The American Water Works Association (AWWA) points to the fact that whereas nine regulations were finalized in the 17-year period from 1975 to 1992, 10 new regulations were being finalized over a six-year span from 1998-2004. The newer regulations also are more complex-diverging from simple maximum contaminant level (MCL) based regulation of the past. As one regulatory writer put it, “future regulations promise even more complexity,” noting these complex regulations also are being applied to a smaller number of contaminants per regulation.
With more “ink” devoted to regulating each contaminant, facility certified operators and engineers are the ones who get to wade into the quagmire. And as more state agencies suffer cutbacks due to a tighter economy and leaner budgets, more responsibility for determining what they have to comply with, how to achieve it and avoiding penalties later has shifted directly to the facilities. This further complexity, in turn, may require more complex treatment or treatment schemes.
Arsenic on the Horizon
In 2001, the U.S. Environmental Protection Agency (EPA) lowered MCL for arsenic in water. The arsenic MCL went from 50 ppb to 10 ppb, meaning that by the compliance deadline of January 2006, some non-transient, non-community public water systems (NTNCPWS)-which would include industrial workplaces-will be out of compliance on arsenic if actions aren’t taken now. Unknowingly, a facility or operator that may be sampling arsenic on a six-year frequency based on previous “good” results below 50 ppb, may be faced with implementing treatment that brings levels below 10 ppb.
In some cases, state regulatory agencies are proactively looking to determine such problems and to help facilities assess their options for compliance by the impending deadline. But facilities should be proactive and do some early testing. A body of data probably already exists pinpointing the expected compliance for a given facility. In cases where levels are expected to exceed the 10 ppb MCL, facilities may have to evaluate options such as installing centralized or decentralized treatment, chemical addition, blending, siting new wells, or receiving delivered drinking water with appropriate waivers and/or modifications to plumbing to prevent access to non-potable water. Each option carries a different set of considerations for implementation.
Stage 1 D/DBP Rule
As of Jan. 1, 2004, all groundwater systems, as well as surface water (or surface-water-influenced systems) that use chemical disinfection, are required to do additional testing and reporting on new parameters per the Stage 1 Disinfectants/Disinfection Byproducts (DBP) Rule. Specifically, they’re now required to look for DBPs such as total trihalomethanes (TTHMs) or five haloacetic acids (HAA5s), and that disinfectant levels are below a ceiling concentration called the maximum residual disinfectant level (MRDL). These regulated substances must be tested and reported at specific frequencies depending on site classifications. For many, they’re reported once per plant per year in the month of warmest water temperature.
The contaminants regulated by the Stage 1 D/DBP Rule are more immediate examples of the complexity of emerging regulations, with a new class of potential violations. MRDLs have been set for chlorine, chloramine and chlorine dioxide disinfectants at 4 ppm as Cl2, 4 ppm as Cl2, and 0.8 ppm as ClO2, respectively-with formal reporting samples for chlorine and chloramines required at the same time as coliform compliance sampling. Where chlorine dioxide is used, systems also must sample for chlorite, whose MCL is set at 1.0 ppm. And systems that ozonate anywhere in the potable process must now look for bromate ion (BrO3-), regulated to 0.010 ppm.
Muncipally Supplied Plants
Industrial water users receiving a water supply from municipal sources are being affected, or may be affected in the near future, by new water regulations and/or concepts being determined now in regulatory circles for future safe water provision.
Aimed at trying to minimize the formation of some potentially-carcinogenic DBPs, particularly in surface water systems, many municipalities converted to chloramines disinfection. But its use may have unintended consequences on water chemistry that may in turn affect industrial systems. Chloramines (chlorine in the presence of ammonia) persist longer in water systems, providing a disinfection residual that reaches further into a distribution system. When chloramines break down, though, they release ammonia via a number of pathways. Over time, the ammonia can serve as a nitrogen source for nitrifying bacteria, which in turn can become responsible for microbiologically-induced corrosion (MIC), or increases in biological activity in incoming water, or biofilm production. Chloramines can also change the redox chemistry of water, causing re-dissolution of pipe scale. This was seen in Washington, D.C., where such a change contributed to much higher lead levels in drinking water, for example.
For industrial users, the switch to chloramines has not only potable water effects, but process water implications. These may simply add to capital equipment costs with respect to corrosion and fouling. Compared to chlorine removal with simple activated carbon systems, though, chloramine removal can require several times the amount of exposure time to carbon for effective removal. Exposure times can be tenfold, requiring possible equipment modification. Furthermore, MIC on copper or other process piping may not be evident until several years after the change.
Industrial facilities that get potable water from small municipalities may involuntarily become part of a new concept of community drinking water treatment: point-of-use (POU) or point-of-entry (POE) treatment-sometimes called “decentralized treatment.”
Decentralized treatment-the application of small treatment devices for reduction of a contaminants at the point where water is consumed-capitalizes on the fact that those contaminants whose primary hazard route is ingestion can be dealt with economically by treating just the 2% of water that’s consumed. The AWWA Research Foundation’s Study #2730 focuses specifically on this topic. In certain scenarios, decentralized treatment is more economical than treating 100% of the water centrally, an option that can require substantial capital and result in oppressive water rate increases, especially for large-volume water users. It also compares favorably to alternate source water such as bottled water.
Administering decentralized treatment using units such as reverse osmosis membranes or faucet filters, for example, is receiving its greatest push as a result of the arsenic MCL change mentioned above. EPA field studies testing feasibility of POU/POE devices are examples of such activity. But many other contaminants are also candidates for decentralized removal-radium, uranium, perchlorate, and MTBE to name a few. The EPA has already issued guidance for POU treatment and is strongly considering implementing regulatory changes to the SDWA to allow such cost-saving treatment options in the municipal “toolbox.” The case for decentralized treatment is bolstered by the fact that contaminants receiving scrutiny in minute quantities in water-such as pharmaceutically-active compounds (PhACs), endocrine disruptors, and naturally-occurring cyanotoxins-are proving to be numerous, and even harder to remove than many compounds regulated to this point.
Future municipal treatment may find difficulty keeping up with the cost to tackle these new contaminants as well as those found to pose potential health threats at smaller and smaller levels in water. And any investment into new or expanded centralized treatment will be passed on as rate hikes. Keeping water rates in check is the largest impact of decentralized treatment on industrial facilities, especially those with drinking water and process water demands supplied by municipalities.
With such a turbulent regulatory horizon looming for entities providing potable and process water, industrial facilities may need to seek a number of sources for help with staying on top of water issues. First, facility owners need to be heard on proposed changes to regulations that will affect them. Keep open channels to regulators and, at the very least, offer comments on proposed regulations to them in writing. Operators should participate in, and use to their advantage, various associations or organizations whose mission is to monitor proposed changes in the field.
Some facilities may consider contracting potable water responsibilities through “circuit riders”-individuals or companies that handle compliance issues (sampling, paperwork, troubleshooting, design, etc.) on a fee basis. Many small water treatment companies take on this work because they understand the contaminants, local water chemistry and treatment technologies for dealing with them. They also forge contacts at the state level that can help avoid costly compliance problems. Circuit riders see more things that can go wrong with a water system and know how to prevent them from occurring, and how to implement a proper solution.
Those interested in “going it alone” should, at very least, consistently monitor the USEPA website (www.epa.gov) and their state regulatory agency website for changes, comment periods, etc. No matter the choice, NTNCPWS facilities cannot afford to wait the 6-year trickle-down period when new regulations take to reach their facilities. They must become more involved in the process of vetting the proposals.
About the Author:
Mark V. Rowzee is the education director of the Water Quality Association, which is based in Lisle, IL. This article is adapted from a paper he presented at the International Water Conference in Pittsburgh in October 2004. Rowzee can be reached at 630-505-0160 or firstname.lastname@example.org.