Environmental Issues > Water Main Page > All Water Documents

Arsenic and Old Laws
A Scientific and Public Health Analysis of Arsenic Occurrence in Drinking Water, Its Health Effects, and EPA's Outdated Arsenic Tap Water Standard

Top of Report


Table 3

46 Largest Water Systems with Average Arsenic Levels Over 5 ppb (Ranked by Largest Population First)

Note: To print portions of this chart, in the Print dialogue box choose Properties and Paper and set to Legal and Landscape and click OK; under Print Range choose "from 1 to 1" and click OK (this will print one page and lock in settings); then use Print Preview to determine which page(s) to print.

Natural Resources Defense Council, February 2000.
Based on EPA's 25-State Arsenic Database of Samples Taken and Reported to States from 19801998 (see important note below).
Contact Your Water System or State for All Sample Results.
Rank Water System Name State County Population Served Low Est. of Average Arsenic Level (ppb) Best Est. of Average Arsenic Level (ppb) # Samples in Which Arsenic Was Detected # of Samples in Which Arsenic Was Not Detected Min Level Found (ppb) Max Level Found Most Recent Sample Reported in EPA Database (ppb) Date of Most Recent Sample Reported in EPA Database
1 LOS ANGELES-CITY, DEPT. OF WATER & POWER CA LOS ANGELES 3600000 4.2 6.9 92 290 <1.0 73.3 (av) <2.0 3/4/97
2 PHOENIX MUNIC WATER SYS AZ MARICOPA 1000000 4.6 5.0 312 100 0.7 37.0 8.7 3/5/98
3 EL PASO WATER UTILITIES-PUB SERV B TX EL PASO 620000 6.6 6.8 42 10 <1.0 16.6 (av) 7.5 10/24/96
4 SOUTHERN NEVADA WATER SYSTEM NV CLARK 500000 5.0 5.0 1 0 5.0 5.0 5.0 4/17/96
5 ALBUQUERQUE WATER SYSTEM NM BERNALILLO 417279 14.1 14.2 188 15 <1.0 60.0 (av) 9.5 1/6/98
6 MESA, MUNIC WATER DEPT. AZ MARICOPA 350000 7.0 9.5 94 127 0.5 50.0 (best av) 8.4 5/21/97
7 CORPUS CHRISTI CITY OF TX NUECES 270000 6.5 6.5 5 0 4.8 8.1 7.0 2/14/96
8 STOCKTON EAST WATER DISTRICT CA SAN JOAQUIN 250000 2.2 6.1 4 14 2.0 13.0 (best av) 4.0 6/13/94
9 RIVERSIDE, CITY OF CA RIVERSIDE 245000 2.3 5.4 49 234 <2.0 100.0 (av) <2.0 5/15/97
10 SCOTTSDALE, MUNIC WATER AZ MARICOPA 174170 10.0 11.1 149 55 <1.0 50.0 (av) 8.0 2/25/98
11 GLENDALE MUNIC WATER CC AZ MARICOPA 150000 5.1 5.9 45 17 1.7 21.0 (av) 6.1 9/16/97
12 KALAMAZOO MI KALAMAZOO 150000 5.5 5.5 13 3 <0.3 33.0 <1.0 12/15/96
13 SAN BERNARDINO CITY CA SAN BERNARDIN 137738 3.1 6.2 11 242 <2.0 440.0 <2.0 3/10/97
14 CHANDLER, MUNIC WTR DEPT AZ MARICOPA 132353 5.6 7.6 121 129 <5.0 56.0 8.0 2/23/98
15 DESERT WATER AGENCY CA RIVERSIDE 125000 1.9 5.3 13 118 <2.0 20.0 (av) <2.0 2/18/97
16 VENTURA WATER DEPARTMENT CA VENTURA 105000 5.3 8.0 21 65 <2.0 43.0 <2.0 10/7/96
17 CWS - SALINAS CA MONTEREY 100300 2.0 5.6 16 95 <5.0 42.0 (av) 15.0 2/25/97
18 DOMINGUEZ WATER CORP CA LOS ANGELES 100000 1.7 6.0 1 29 <5.0 50.0 < 10.0 2/18/94
19 MIDLAND CITY OF TX MIDLAND 97458 10.8 11.1 7 2 <2.0 31.9 (av) 4.6 6/11/96
20 LOS ANGELES CO WW DIST 4 & 34-LANCASTER CA LOS ANGELES 96073 12.0 14.5 82 85 <2.0 103.0 (av) 10.7 12/26/96
21 NORMAN OK OK 80000 36.3 36.3 25 2 2.0 120.0 46.0 12/1/98
22 PEORIA, CITY OF AZ MARICOPA 74000 4.1 6.3 44 40 1.6 23.0 8.7 6/27/97
23 HOUSTON-GREENSPOINT TX HARRIS 72027 7.9 4 0 2.6 10.3 2.6 7/27/95
24 YORBA LINDA WATER DISTRICT CA ORANGE 70000 3.0 5.9 20 32 2.0 18.0 4.6 11/19/96
25 VICTORIA CITY OF TX VICTORIA 67353 11.2 11.6 3 2 <2.0 23.1 (best av) 11.2 8/13/96
26 GILBERT, TOWN OF AZ MARICOPA 67000 8.8 9.3 43 9 <5.0 29.0 5.0 3/24/98
27 WATERFORD TOWNSHIP MI OAKLAND 66692 7.8 7.8 2 0 5.0 10.6 (av) 7.8 11/30/94
28 CITY OF LAKEWOOD CA LOS ANGELES 66000 13.9 15.1 39 19 <2.0 100.0 (av) 4.1 8/6/96
29 ELSINORE VALLEY MWD CA RIVERSIDE 66000 2.2 5.7 15 49 <2.0 28.0 (best av) 2.0 9/21/95
30 BAKERSFIELD, CITY OF CA KERN 60720 1.5 5.3 14 68 <5.0 17.0 (av) 10.0 2/25/97
31 MONTEREY PARK-CITY, WATER DEPT. CA LOS ANGELES 59000 5.3 6.9 15 17 <2.7 19.2 8.6 7/2/96
32 GREAT FALLS CITY OF MT CASCADE 55097 7.8 7.8 11 0 3.0 18.0 13.0 4/23/91
33 CITY OF CERRITOS CA LOS ANGELES 53300 4.6 6.2 20 12 4.4 11.6 (av) 8.0 9/26/96
34 RANCHO CALIFORNIA WATER DIST CA RIVERSIDE 51672 1.7 5.1 41 128 <2.0 29.0 2.0 5/15/97
35 CITY OF RIO RANCHO SEWER AND WASTEWATER SERV NM SANDOVAL 49999 12.1 12.4 39 8 <0.6 53.0 20.0 7/31/97
36 PETALUMA, CITY OF CA SONOMA 49957 1.4 5.0 1 10 <3.0 15.0 < 10.0 1/28/92
37 TURLOCK, CITY OF CA STANISLAUS 49500 5.1 7.7 36 51 <1.0 58.0 (av) 15.5 11/27/95
38 CITY OF CHINO HILLS CA SAN BERNARDIN 49000 28.2 30.2 30 19 2.0 105.0 (av) 54.6 8/27/96
39 WEST SACRAMENTO, CITY OF CA YOLO 45000 5.5 7.1 29 28 <2.0 15.0 <2.0 6/4/96
40 MANTECA, CITY OF CA SAN JOAQUIN 44500 7.0 9.6 23 25 8.1 25.9 (av) 12.2 4/9/97
41 TRACY, CITY OF CA SAN JOAQUIN 44500 2.8 6.5 11 31 2.0 29.0 2.0 10/24/95
42 PORTSMOUTH, CITY OF OH SCIOTO 44004 1.6 6.2 1 13 <10.0 22.0 < 10.0 8/10/93
43 FLAGSTAFF MUNICIPAL WATER AZ COCONINO 41200 3.6 6.8 15 35 1.0 95.0 1.0 7/8/97
44 MOORE OK OK 40300 12.3 12.6 59 19 <2.0 42.0 (av) 34.5 11/30/98
45 SUN CITY WEST AZ MARICOPA 40000 14.4 16.0 19 9 <10.0 34.0 (av) 19.5 7/15/97
46 ST. GEORGE CITY UT WASHINGTO 40000 8.0 8.5 41 35 <1.0 48.0 15.0 2/22/96
* Important note regarding arsenic levels in individual water systems listed in this report: The information on arsenic levels in public water systems included in the NRDC report Arsenic and Old Laws is derived from the U.S. Environmental Protection Agency's (EPA) 25-state arsenic database, which includes samples taken from 1980 to 1998. NRDC has not independently verified these data, which EPA collected from state drinking water program officials, and compiled into the 25-state arsenic database. Additional sampling may have been completed for some water systems after the EPA database was compiled. To verify information on all sampling completed to date for a public water system, contact your state drinking water program (call EPA's drinking water Hotline at 800 426-4791 for state contacts) or your water system.

Corrections: Because of an error in data reporting by the state of California, in the print version of this report and the earlier online version, Alameda County Water District, City of Antioch Water Department, and City of Santa Clara Water and Sewer Utilities were incorrectly included in charts identifying water systems with high average arsenic levels.

NRDC has been informed that the monitoring results reported to the state of California by the City of Milpitas, which the state then reported to US EPA (and ultimately were reported by NRDC based on EPA's database), were for emergency wells not currently in use. This information was not indicated in EPA's database. The City of Milpitas has provided information indicating that the water used by the City of Milpitas has been consistently below 2 parts per billion (ppb).

Sign up for NRDC's online newsletter

See the latest issue >

Water on Switchboard

NRDC experts write about water efficiency, green infrastructure and climate on the NRDC blog.


Recent Water Posts

How Pollution and Climate Change Threaten Our Beaches
posted by Ben Chou, 6/26/13
"Testing the Waters" for Bacteria That Can Make You Sick
posted by Becky Hammer, 6/26/13
NRDC Report: Cleaning Up America's Beaches Requires Leadership on Polluted Runoff
posted by Jon Devine, 6/26/13
Give the Gift That Will Make a Difference: A Long Cool Drink

NRDC Gets Top Ratings from the Charity Watchdogs

Charity Navigator awards NRDC its 4-star top rating.
Worth magazine named NRDC one of America's 100 best charities.
NRDC meets the highest standards of the Wise Giving Alliance of the Better Business Bureau.


Donate now >

Related Links

Share | |