New Surface Water Rules Will Kick In for Large
Systems
Volume 60, Number 3-- October 2001
Jan. 1, 2002, deadline for surface water systems
serving 10,000 or more
New Disinfectant/Disinfection Byproducts and Interim
Enhanced Surface Water Treatment rules, required under final rules
published by U.S. EPA in December of 1998, will become effective
next Jan. 1 for large surface water systems---those serving a
population of at least 10,000. Small surface water systems---those
serving fewer than 10,000---will have to comply with the disinfectant/disinfection
byproduct rules by Jan. 1, 2004. These small supplies eventually
will have to meet the new surface water treatment rules as well,
but that deadline has not yet been set.
Under the rules becoming effective next Jan. 2,
large systems will be required to monitor for chlorine or chloramines
residual levels at the same time and location that total coliform
samples are taken. The running annual average of disinfectant
residuals cannot exceed 4.0 parts per million.
The systems will also have to monitor for total
trihalomethanes (TTHMs) and for haloacetic acids (HAA5), with
the number of samples needed based on the size and type of system.
The new maximum contaminant levels for TTHMs is 80 ppb. For HAA5,
it will be 60 ppb.
Surface water systems will also be required to monitor
monthly for total organic carbon (TOC) in raw and finished water,
and for raw water alkalinity, and will have to show the TOC levels
are low in both raw and finished water, or that specific percentage
removals of the TOCs is being achieved.
