Final, Statutory, June 18, 1989. Final, Judicial, May 31, 1996. The contaminant was deferred from the Phase V regulation in order to allow the Agency time to focus on implementation issues arising from the proposal concerning the risk of sulfate in drinking water to specific subpopulations. Sulfate can cause diarrhea in infants and in adults not acclimated to high sulfatecontaining water, such as travellers. Persons who are acclimated to high sulfate-containing water suffer no adverse effects from its consumption.
Sulfate occurs naturally in soil and is also found in surface after as result of acid rain.
Most of the affected systems serve populations of less than 3,000 and are transient systems not in service year-round. Known treatment technologies include reverse osmosis, ion exchange, and electro dialysis. SAN No. 3176. EPA is considering an option for compliance which would be an alternative to central treatment. The alternative would include public education, public notification, and provision of alternative water to affected populations.