Required precautionary boil water alert for all of Monroe County due to violation of turbidity standard
As of about 3:25 p.m. on Saturday (Aug. 17) Monroe County residents are being advised to boil their water as a precaution, because of an IDEM (Indiana Indiana Department of Environmental Management) requirement that such an advisory be issued when drinking water standards are violated.
The standard in question is one for “turbidity” which is a measure of how clear or cloudy the water is. According to city of Bloomington utilities (CBU), high turbidity itself has no health effects.
However, turbidity can interfere with disinfection, and provide a medium for microbial growth, according to CBU.
According to CBU communications manager Holly McLauchlin, it is all of Monroe County that is under the precautionary boil water advisory, not just CBU customers. That’s because CBU is the wholesale supplier to other water utilities in the county.
According to a city of Bloomington news release, all Monroe County residents should follow these instructions:
- If you have cloudy water, run COLD water from a sink or tub until clear water flows
from the faucet. - Boil all water used for drinking, cooking, and oral hygiene for at least 2 minutes prior
to consumption. - It is not necessary to boil water for other uses.
[Updated Aug. 18, 2024 at 8 p.m. The news release from the city of Bloomington indicates that the boil water advisory will go through Monday, Aug. 19 at 9 a.m. unless otherwise notified. As of Sunday evening, there has been no subsequent notification to revise that time and day.]
[Updated Aug. 19, 2024 at 9:05 p.m. An announcement that the countywide boil water advisory has been lifted was sent out via the Monroe County emergency alert system just after 9 a.m. on Monday. An isolated new advisory has been issued just for Gentry Estates—specific addresses are listed on the CBU website.]
According to McLauchlin, the excessive turbidity level, measured on Friday Aug. 16, exceeded the 1 NTU (Nephelometric Turbidity Unit) permitted by the IDEM rule.
The precautionary boil water advisory cannot be lifted until a round of tests is completed, according to McLauchlin, which she thinks will be completed by Monday at the latest but possibly sooner.
Generally, high turbidity is associated with suspended particles. For this incident, the particles in question are sand used as a normal part of the water treatment process.
Due to an operator error, some sand that is used as a part of the disinfection process, spilled over into a part of the treatment flow that comes after the sand filter, CBU communications manager Holly McLauchlin told The B Square.
As a normal part of the treatment process, already-chlorinated water is filtered through a sand well, McLauchlin said. After a certain volume has been filtered the sand gets a little “grubby,” she said. At that point, there’s a normal process of backwashing the sand to clean it.
What happened to cause the increase in turbidity was that during the backwashing process, some water, with some sand, sloshed forward into the next phase of the treatment process, according to McLauchlin.
The precautionary boil water message was sent through Monroe County’s emergency alert system around 3:25 p.m. on Saturday afternoon. McLauchlin said she called Justin Baker, who is Monroe County assistant director of emergency management to send out the message.
The emergency alert was followed a few minutes later by the news release from the city of Bloomington.
