Civil Engineering Reference
In-Depth Information
TABLE 1-4. 1979 National Interim Primary Drinking
Water Regulations
Contaminant
MCL
Inorganic
Arsenic
0.05 mg / L
Barium
1.0 mg / L
Cadmium
0.01 mg / L
Chromium
0.05 mg / L
Fluoride
At
53.7
F(
12.0
C)*
2.4 mg / L
At 53.8-58.3
F (12.1-14.6
C)
2.2 mg / L
At 58.4-63.8
F (14.7-17.6
C)
2.0 mg / L
At 63.9-70.6
F (17.7-21.4
C)
1.8 mg / L
At 70.7-79.2
F (21.5-26.2
C)
1.6 mg / L
At 79.3-90.5
F (26.3-32.5
C)
1.4 mg / L
Lead
0.05 mg / L
Mercury
0.002 mg / L
Nitrate (as N)
10.0 mg / L
Selenium
0.01 mg / L
Silver
0.05 mg / L
Organic
Endrin
0.0002 mg / L
Lindane
0.004 mg / L
Toxaphene
0.005 mg / L
Methoxychlor
0.1 mg / L
2,4-D
0.1 mg / L
2,4,5-TP (Silvex)
0.01 mg / L
TTHM
0.1 mg / L
Radiological
Alpha Emitters
Radium-226
5 pCi / L
Radium-228
5 pCi / L
Gross alpha activity (excluding
radon and uranium)
15 pCi / L
Beta and Photon Emitters†
Tritium
20,000 pCi / L
Strontium-90
8 pCi / L
Turbidity (NTU)
1 NTU‡
Source:
Reference 6.
* Average annual maximum daily air temperature.
† Based on a water intake of 2 L / d. If gross beta particle activity exceeds
50 pCi / L, other nuclides should be identified and quantified on the basis
of a 2-L / d intake.
‡ One turbidity unit based on a monthly average. Up to 5 NTU may be
allowed for the monthly average if it can be demonstrated that no in-
terference occurs with disinfection or microbiological determination.
