About 88,000 people in the Lutherville area – some in northern Baltimore City, but most in Baltimore County – are being warned by mail that the city water they use had levels of haloacetic acid that exceeded the state and federal legal limits.
Quarterly sampling conducted at one testing location between October 2012 and September 2013 showed an average contamination level of 62 ppb (parts per billion), according to Jeffrey Raymond, a spokesman for the Baltimore Department of Public Works. The maximum contamination level (MCL) set by state and federal law is 60 ppb.
Raymond discussed the violation with The Brew this week by email, following the agency’s disclosure of it via a press release sent to the media late Friday, the day after Thanksgiving.
People drinking water containing HAA5 at levels in excess of the maximum contamination level over many years are at an increased risk for cancer, according to the Environmental Protection Agency.
The city’s release called the violation “not an emergency.” Raymond explained this via email, saying that the city’s monthly sampling when averaged (as opposed to the EPA’s required quarterly sampling) produced a number below 60 ppb. Still, DPW’s press release warned that certain people may be at increased risk in the affected area.
“Customers with severely compromised immune systems, infants, pregnant women, and the elderly are at an increased risk and may wish to seek advice from their health care providers,” the DPW release said.
Water suppliers are required by federal law to notify customers no later than 30 days after the system learns of a violation.
Organic Matter in Distribution Lines
Asked how long these customers may have been exposed to the contaminated drinking water, Raymond said the high levels reflect an average of four tests over the past year and that there have been “no violations in recent years.”
HAA5 is the name for a group of five acids which are a common undesirable byproduct of drinking water chlorination. Chlorine from the water disinfection process can react with organic matter and small amounts of bromide present in water to produce various haloacetic acids.
The organic matter may explain why the violation occurred in the city’s distribution system, rather than its filtration plants.
“HAA5 values for water leaving our three treatment plants are relatively low, but the size and age of the distribution system contributes to higher levels in some isolated areas,” the DPW release said.
As for fixing the problem in the distribution system, it does not appear that DPW has many immediate remedies at hand. In the release, they cite “covering finished water reservoirs, increasing mixing of water at storage tanks and replacing older distribution pipes.”
As The Brew has reported, the miles-long network of old distribution pipes transporting city water are likely to be much encrusted with organic matter and rust. Raymond, in discussing the violation, focused more on natural causes:
“Large storms such as the ones received last summer contribute to the amount of natural organic matter in the water.”
The release said the DPW “routinely monitors dozens of sampling stations across our distribution area for the presence of drinking water contaminants.” But in his email to The Brew, Raymond said the city is “measuring only the 16 sites with the highest historic levels, not the numerous other sample locations that were used prior to April 2012.”
Before a federally-mandated change, he said, the city sampled at 30 locations, combining the results to come up with a system-wide average.
Meanwhile, although HAA5 averages have been below the legal limit in the city’s filtration plants in the past six years, levels have been increasing there, judging by the Annual Water Quality Reports buried deep within the DPW website.
The averages and occasional spikes in HAA5 levels measured at the Ashburton and Montebello plants in Baltimore City were strikingly higher in 2011 and 2013 than in previous years.
In 2011 and 2012 respectively, Ashburton’s HAA5 spikes (HLD levels, meaning Highest Level Detected) reached 151 ppb and 102 ppb. Going back to 2006, these spikes hovered in the high 60s and low 70s.
Likewise with Ashburton’s HAA5 averages, which were 59 and 58 in 2011 and 2012. Going back to 2006, the averages were generally in the 30s. The Montebello plants’ results show a similar pattern.
Asked about the cause of the apparent rise in HAA5 levels, Raymond provided this response:
“There are small fluctuations measured in parts per billion. The ongoing 24/7 process of treating and testing the drinking water before it leaves the plants keeps the water supply within the strict state and federal standards. And as we stated in the press release, better mixing the stored water and flushing the system are among the ways we keep within those standards at the tap.”