Civil Engineering Reference
In-Depth Information
Maximum Contaminant
Level (MCL)
(mg / L unless noted)
Name of Contaminant
Health Effects of Contaminant
Monitoring Requirements
Antimony
Arsenic
1
0.006
0.05
Decreased longevity, blood effects
Dermal and nervous system toxicity effects;
bladder and kidney cancer
Once per year for surface waters. Once every
three years for groundwater for IOCs, not
including Asbestos, Lead and Copper, Ni-
trate, and Radionuclides
Asbestos (fiber length
10
m)
7 MFL
2
0.004
0.005
0.1
Lung tumors / cancer risk
Heart / cardiovascular system effects
Bone / lung effects / cancer risk
Kidney effects
Kidney / nervous system / circulatory effects
Asbestos. Once every nine years
Barium
Beryllium
Cadmium
Chromium (total)
Copper
Treatment technology
(Action Limit
Gastrointestinal effects
Copper: Same as lead
1.3)
Cyanide
0.2
Spleen / brain / liver effects
Fluoride
4
Skeletal effects
Gross alpha Emitters
15 pCi / L
Cancer risk
Gross alpha and beta: Every four
years—quarterly samples
Gross beta Particle and Photon Emitters
4.0 mrem
Cancer risk
Lead
Treatment technology
(Action Limit
Cancer risk / kidney / nervous system effects;
highly toxic to infants
Lead: Follow-up monitoring is every six
months after corrosion controls are initiated
or optimized. Systems consistently meeting
ALs can reduce monitoring to annually and
then to every three years.
0.015)
Mercury (inorganic)
0.002
Kidney / central nervous system disorder
Nickel
0.1
Nervous system / Liver / heart effects
Nitrate (as N)
10
Methemoglobinemia (blue baby syndrome)
Nitrate: Groundwater annually; surface water
quarterly
Nitrite (as N)
1
Methemoglobinemia (blue baby syndrome)
Nitrite: One sample every three years
Radium 226 plus 228
Current 5 pCi / L (com-
bined)
Cancer risk
Radium: Every four years—quarterly samples
Selenium
0.05
Nervous system / kidney effects
Thallium
0.002
Kidney / liver / brain / intestine effects
1
On June 22, 2000, EPA proposed a lower MCL for arsenic, of 0.005 mg / L. Rule is expected to be final by June 22, 2001.
