Water Chemistry

        Definitions:

                    MCLG: Maximum Contaminant Level Goal, or the level of a

                    contaminant in drinking water below which there is no known or

                    expected risk to health.  MCLGs allow for a margin of safety. 

                    MCL: Maximum Contaminant Level, or the highest level of a

                    contaminant that is allowed in drinking water. MCLs are set as close

                    to the MCLGs as feasible using the best available treatment

                    technology.

                    AL:  Action Level, or the concentration of a contaminant which, when

                    exceeded, triggers treatment or other requirements which a water

                    system must follow. 

                    TT:  Treatment Technique or a required process intended to reduce

                    the level of a contaminant in drinking water.

Abbreviations:

                    mrem/yr – millirems per year (used to measure radiation absorbed by

                    the body).  nd – not detectable at testing limits.

                    n/a – not applicable.

                    ppm – parts per million or milligrams per liter. 

                    ppb – parts per billion or micrograms per liter.

                    pCi/l – picocuries per liter, used to measure radioactiviity.

                    % pos/mo – percent positive samples per month.