UCM is upping the game again. Since 2001, every water supplier in the United States has become familiar with the Unregulated Contaminant Monitoring (UCM) program.  As part of the Federal Safe Drinking Water Act (SDWA), the program monitors the occurrence of newer drinking water contaminants in the nation’s water supply.

All large public water suppliers have now begun monitoring for a new list of unregulated contaminants.  Whether you are a groundwater source water supplier or a surface water system, supply and treat your own water source or purchase water from a larger system, suppliers who serve more than 10,000 people will collect samples under Unregulated Contaminant Monitoring Rule 3 (UCMR3) sometime between the beginning of 2013 and the end of 2015.

By now you should have received your notice from the USEPA outlining when your samples must be collected and from what locations.  Unless you are a purchasing water supplier (what EPA calls a “Consecutive System”), you’ve gone through UCMR monitoring twice before.

So what’s different about UCMR3, and why should you be concerned?

It’s true that the previous two UCMR monitoring events did not really yield a lot of new surprises.  In the Northeast and Mid-Atlantic U.S., problems with Methyl tert-butyl ether (MTBE) and perchlorate were well on the way to being understood almost a decade before UCMR1 (2001-03) became the first national occurrence study for these two contaminants.  UCMR2 provided few new insights into emerging risks, except for some systems that were using chloramines for disinfection and detected nitrosamine disinfection byproducts.

However, the water supply industry’s experience with the thirty UCMR3 compounds could be very different.

UCMR3 consists of 30 new compounds, including Volatile Organic Compounds (VOCs), PFCs and, for the first time, hormones and viruses.  A primary concern common to each group discussed below is the fact that UCMR3 will utilize analytical methods which can detect very low concentrations of these chemicals.  These test methods could capture watershed impacts from consumer use of products, not just industrial activities or chemical manufacturing. Experience has shown that when analytical capabilities are refined to detect lower concentrations, the frequency of detection of known contaminants increases.

Let’s break it down into each group and discuss the facts:

UCMR3 includes VOCs that have been occasionally encountered using common VOC analytical methods. However, the analytical methods specified in UCMR3 will allow detection of much lower concentrations for two VOCs that have been detected previously in some groundwater in this area: 1,2,3 trichloropropane and 1,1 dichloroethane. The reporting limits for these UCMR3 VOCs are as low as 0.03 ppb, compared to 0.5 ppb in common laboratory procedures. Given the history and use of these two VOCs, and the recognition that 1, 1 dichloroethane is a breakdown product of a very common solvent-trichloroethane, there is concern that this pattern will continue in UCMR3, meaning more VOCs will have lower thresholds in future UCMR actions.

1,4 dioxane is a chemical used to stabilize certain solvents.  Its chemical properties make it difficult to remove from water.  The EPA considers it to be a probable human carcinogen and consumer activists are working to get manufacturers to reformulate laundry detergents and cosmetic products that contain it.  It is classified as an ether—a category that includes other persistent watershed contaminants, like MTBE.  The analytical method for 1,4 dioxane will be able to detect extraordinarily low concentrations—as low as 0.07 ppb.

UCMR3 contains a group of six trace metals many of which occur naturally.  Most are necessary and beneficial in small quantities in the diet.  Many are found in vitamin supplements. One significant exception is hexavalent chromium, or chrome-6, which has received extensive press coverage in which it is referred to as the “Erin Brokovich chemical”.  Press coverage of industrial contamination has generated public concern, but there are a number of significant knowledge gaps, among which is the occurrence frequency of this contaminant in sub-ppb concentrations, and the relevance of animal studies to human health risk.  UCMR3 will attempt to evaluate whether naturally occurring and beneficial trace trivalent chromium can be transformed to hexavalent chromium during water treatment processes involving chlorine or other oxidants.

Chlorate is an inorganic salt that since the late 1980s has been known to form as a breakdown product of at least two disinfectants used in water treatment—sodium hypochlorite and chlorine dioxide. Under the 1996 Information Collection Rule (ICR was an EPA regulation that predated UCMR monitoring) a few very large water suppliers developed some data on chlorate occurrence.  Because of ICR monitoring, we also know that chlorate can occur as a groundwater contaminant (probably from residential and commercial uses of products that contain hypochlorite).  In UCMR3 monitoring, EPA will try to develop data that will allow understanding of how frequently it occurs as a disinfection byproduct, and how concentrations may change as water travels through the distribution system.

Five PFCs that have been detected in water supplies near industries manufacturing Teflon and certain chemicals used in stain-release fabrics.  The EPA has specified an analytical method that can detect concentrations of some of these acids as low as 0.01 ppb.

The presence of hormones in water sources has been under study for over a decade.  UCMR3 will incorporate a significant national study by requiring that public supplies serving over 100,000 people sample for seven hormones in addition to the other UCMR3 sampling requirements imposed on smaller suppliers.  Here, too, the analytical reporting level is extremely low—as low as 0.0001 ppb.

UCMR3 incorporates a special virus study that will be conducted directly by EPA—the Agency will be collecting the samples from a specially selected group of 800 very small, non-disinfecting groundwater supplies that have water sources in relatively unique geological settings.  A special part of the UCMR Rule called Pre-Screen Testing allows use of new-method technologies not commonly utilized by drinking water labs.  Here, they will be looking for two specific virus groups known to cause disease, and which have been associated with water contaminated by sewage.  Enterovirus is a group of viruses which includes echovirus, poliovirus and a virus that causes a disease in children called hand-foot-and-mouth disease.  Norovirus has been associated with a number of water, food and direct-contact outbreaks, and is familiar to people as the virus group which caused a number of outbreaks on cruise ships in recent years.

Public reporting and transparency throughout the regulatory process is at the core of the Safe Drinking Water Act. UCMR contaminant detections will require notification in the water supplier’s Consumer Confidence/Annual Water Quality Report. However, since the UCMR incorporates unregulated contaminants, only limited data may be available on the public health significance of detected concentrations, and the sources of contaminant occurrence.  For water suppliers that experience detection, the “information gaps” about these contaminants—their health significance and the technological information to treat and remove the contaminants in a cost-effective, sustainable manner—will pose an ongoing challenge to water suppliers in maintaining public confidence.

• Become familiar with basic information about UCMR3 contaminants.

• Review and understand your UCMR3 monitoring requirements and scheduling needs. Know when and where you will need to collect these samples. If you experience problems meeting these regulatory requirements, contact the EPA UCMR3 Help Desk at 1-800-949-1581, or by e-mail.

• If you experience new detections of UCMR3 contaminants in your distributed water, consider additional data development on source water occurrence, existing treatment effectiveness and distribution system processes that may affect contaminant concentrations.

• Monitor EPA’s decision-making process regarding UCMR contaminants.

For more information, please contact Paul Granger at 631.756.8000 or pgranger@h2m.com.