6EPA
United States
Environmental Protection
Agency
Office of Water
4603
EPA811-F-94-004
June 1994
 Controlling Microbial  Contaminants and Disinfectants/
 Disinfection By-products: Benefits and Costs
Benefits

Microbial contaminants and disinfectants and
disinfectant by-products (D/DBPs) can have ad-
verse affects on public health. Microbial contami-
nants can cause diarrhea, dysentary, and hepatitis,
and may even be fatal for individuals with weak-
ened immune systems. Chronic exposure to disin-
fectants and disinfection by-products may cause
cancer, liver and kidney damage, heart and neuro-
logical effects, and effects to unborn children.

The proposed D/DPB rule and the proposed
enhanced surface water treatment (ESWT) rule for
controlling microbial contaminants would signifi-
cantly reduce public health risks associated with
drinking water.

•   Disinfectants and disinfection by-products
   would be controlled for all systems for the first
   time.

•   The level of exposure to chlorinated disinfection
   by-products would be reduced on average by
   20%-30% for an individual currently being
   exposed. Exposure to other non-chlorinated
   by-products would also be reduced.

•   Hundreds of thousands of cases of disease
   associated with microbial contamination could
   be eliminated each year.

•   Controls on the potentially deadly parasite,
   Crvptosporidium. would be implemented for
   larger systems serving more than 10,000
   people.
                    •   Enhancing surface water treatment to further
                       reduce microbial contamination would have
                       the added benefit of removing organic matter,
                       the material which combines with chlorinated
                       compounds during disinfection to form harmful
                       by-products.

                    Costs

                    Disinfectants/Disinfection By-products
                    Control:

                    •   Total annualized costs are estimated at $ 1
                       billion per year.

                    •   About 50% of all households would incur no
                       costs to modify existing treatment.

                   •   About 1 % of households would experience
                       costs of over $ 16 per month.

                   •   Of the remaining 49% of households, the
                       average cost would be less than $2 per
                       month.

                   Enhanced Surface Water Treatment:

                   •   Total annualized costs will depend on which
                       of the proposed treatment options are se-
                       lected in the final rule-making; however, the
                       cost of one option being proposed would be
                       less than $500 million per year.

                   •   Based on this option, for systems serving
                       10,000 people or more, the average cost per
                       household would be less than $20 per year.

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