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Update: May 2004

Current Massachusetts Regulatory Limit
MMCL = Treatment Technique. Refer to 310 CMR 22.20. ORS has adopted the MCL published by the U.S EPA.

Federal Regulatory Limit
Under U.S. EPA's Surface Water Treatment Rule, systems using surface water or groundwater under the direct influence of surface water must achieve a 99.9% removal/inactivation of viruses (U.S. EPA, 2002). The MCLG for viruses is zero.

Basis for Criteria
The MCL for viruses is based on a Treatment Technique as described above.

Critical Effects
Enteroviruses (including polioviruses, coxsackieviruses [groups A and B], echoviruses, and hepatitis A virus), rotaviruses and other reoviruses, adenoviruses and Norwalk-type agents, comprising more than 100 serological types, constitute the major enteric viruses of human origin. Although viruses are only viable when they infect a living cell, multiply, and then direct processes in that cell, viruses in sewage can reach 10,000-100,000/L and they can survive for months in water and soil. Infection with as little as a single infectious unit can theoretically lead to infection in a susceptible human. A number of outbreaks of hepatitis A have been waterborne. A large number of reported gastroenteritis outbreaks of nonbacterial etiology have probably also been associated with waterborne viruses.Such cases of contamination have been frequently documented over the years, even in the apparent absence of indicator bacteria (U.S. EPA, 1984).

Cancer Assessment: N/A

Biological Pathogen

Analytical Information
: See 310 CMR 22.20 

Analytical Methods
See 310 CMR 22.20

PQLs and analytical methods may have been updated since this guidance value was last revised. Updated analytical methods for drinking water and their associated PQLs may be found at US EPA Drinking Water Analytical Methods .

Federal Register. January 14, 2002. Environmental Protection Agency. Parts 9, 141 and 142. National Primary Drinking Water Regulations: Long Term 1 Enhanced Surface Water Treatment Rule. Final Rule. (67 FR 1811).

U.S. EPA (U.S. Environmental Protection Agency). February 1984. Manual of Methods for Virology. EPA/600/4-84/013.

U.S. Environmental Protection Agency (U.S. EPA). July 2002. List of Contaminants and Their MCLs. EPA 816-F-02-013.