Washington Administrative Code
Title 246 - Health, Department of
WATER SYSTEMS
Chapter 246-291 - Group B public water systems
Section 246-291-170 - Water quality requirements for groundwater source approval
Current through Register Vol. 24-18, September 15, 2024
(1) All water quality samples collected under this section must be:
(2) To meet the requirements for design approval under WAC 246-291-120, a purveyor shall obtain, at a minimum:
(3) When analytical results indicate a presence of coliform bacteria, a purveyor shall do the following:
(4) A purveyor shall collect a confirmation raw source water sample and have the sample analyzed for each parameter that exceeded the MCL in the initial sample, if:
(5) The department or health officer shall not approve the proposed source if:
(6) When an analysis exceeds a secondary MCL in Table 3 or 4 of this section, a purveyor shall include treatment in the Group B system design under WAC 246-291-200 so that drinking water delivered to consumers does not exceed a secondary MCL.
Table 2 Primary Inorganic Chemical Contaminants
|
Substance |
MCLs (mg/L) |
|
|
Antimony (Sb) |
0.006 |
|
|
Arsenic (As) |
0.010* |
|
|
Barium (Ba) |
2.0 |
|
|
Beryllium (Be) |
0.004 |
|
|
Cadmium (Cd) |
0.005 |
|
|
Chromium (Cr) |
0.1 |
|
|
Cyanide (HCN) |
0.2 |
|
|
Fluoride (F) |
4.0 |
|
|
Mercury (Hg) |
0.002 |
|
|
Nitrate (as N) |
10.0 |
|
|
Nitrite (as N) |
1.0 |
|
|
Selenium (Se) |
0.05 |
|
|
Thallium (Tl) |
0.002 |
|
|
Note: |
*The arsenic MCL in Table 2 applies to new and expanding Group B systems. For Group B systems constructed prior to January 1, 2014, the arsenic MCL is 0.05 mg/L. WAC 246-291-360(3) and (4) establish public notification requirements for Group B systems constructed prior to January 1, 2014, with an arsenic concentration exceeding 0.010 mg/L. |
Table 3 Secondary Inorganic Chemical Contaminants
|
Substance |
MCLs (mg/L) |
|
|
Chloride (Cl) |
250.0 |
|
|
Fluoride (F) |
2.0 |
|
|
Iron (Fe) |
0.3 |
|
|
Manganese (Mn) |
0.05 |
|
|
Silver (Ag) |
0.1 |
|
|
Sulfate (SO4) |
250.0 |
|
|
Zinc (Zn) |
5.0 |
|
Table 4 Secondary Physical Characteristics
|
Substance |
MCLs |
|
|
Color |
15 color units |
|
|
Specific conductivity |
700 umhos/cm |
|
|
Total dissolved solids (TDS) |
500 mg/L |
|
Statutory Authority: RCW 43.20.050 and chapter 70.119A RCW. 12-24-070, § 246-291-170, filed 12/4/12, effective 1/1/14.
