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National Drinking Water Database


National Drinking Water Database - Chemical Contaminants

The Most Polluted Communities

51 water utilities reported detecting Strontium-90 in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by population

RankSystem Population Served Positive test results of total reported tests Average Level
(Range)
1Metropolitan Water District of Southern California
Los Angeles, CA
17,000,0007 of 100.11 pCi/L
(0 to 0.41 pCi/L)
2Los Angeles Department of Water and Power
Los Angeles, CA
3,828,7003 of 40.36 pCi/L
(0 to 0.55 pCi/L)
3Las Vegas Valley Water District
Las Vegas, NV
1,181,26316 of 250.25 pCi/L
(0 to 1.13 pCi/L)
4Tampa Water Department
Tampa, FL
550,0001 of 10.2 pCi/L
(0.2 pCi/L)
5South Central Connecticut Regional Water Authority
New Haven, CT
389,3001 of 40.75 pCi/L
(0 to 3 pCi/L)
6City of North Las Vegas Utilities Department
N Las Vegas, NV
282,6002 of 100.14 pCi/L
(0 to 0.81 pCi/L)
7City of Henderson
Boulder City, NV
246,0001 of 50.21 pCi/L
(0 to 1.07 pCi/L)
8Contra Costa Water District
Concord, CA
200,0001 of 190.09 pCi/L
(0 to 1.69 pCi/L)
9Westmoreland Co MA Yough Plant
Greensburg, PA
181,9191 of 10.3 pCi/L
(0.3 pCi/L)
10Erie City Water Authority
Erie, PA
180,0001 of 10.43 pCi/L
(0.43 pCi/L)
11Pomona - City, Water Dept.
Pomona, CA
156,50036 of 610.16 pCi/L
(0 to 1.2 pCi/L)
12City of Oceanside
Oceanside, CA
142,0002 of 40.12 pCi/L
(0 to 0.38 pCi/L)
13Wilmington Water Department
Wilmington, DE
140,0001 of 10.18 pCi/L
(0.18 pCi/L)
14United Water Delaware
Wilmington, DE
105,2702 of 20.22 pCi/L
(0.15 to 0.29 pCi/L)
15San Gabriel Valley WC - Fontana
Fontana, CA
102,5991 of 11.22 pCi/L
(1.22 pCi/L)
16City of Daly City
Daly City, CA
92,3111 of 10.83 pCi/L
(0.83 pCi/L)
17Cal AM Water Company - Monterey
Pacific Grove, CA
92,1151 of 40.01 pCi/L
(0 to 0.06 pCi/L)
18Palmdale Water Dist.
Palmdale, CA
85,0001 of 10.23 pCi/L
(0.23 pCi/L)
19Elsinore Valley Mwd
Lake Elsinore, CA
81,10110 of 120.39 pCi/L
(0 to 1.35 pCi/L)
20City of Napa
Napa, CA
70,0002 of 30.13 pCi/L
(0 to 0.2 pCi/L)