Public Water System: Walnut Valley Water District

MyTapWater.org's tap water quality report is the compilation of data collected from federal, state, and local government agencies, most prominently the EPA. We strive to populate the report with the latest data concerning water contaminants, lead and copper levels, and water quality violations. We only collect drinking water data from public water systems.

PWS Service Information
PWS ID: CA1910234
Type: Community water system
EPA Region: 09
Primary Service Area: Residential Area
Primary Source: Surface water purchased
Population Served: 103,340
Contact Information
HOLMES, MICHAEL
HOLMES, MICHAEL
271 S. BREA CANYON ROAD
WALNUT, CA 91789

This public water system services 1 municipality in 1 county.

Summary Results


A summary view of the the times a water contaminant was tested and found to exceed the level set by the EPA (the MCL).

Maximum Contaminant Levels Exceeded (by year):

Contaminant Detailed Results


This a view of violations of maximum contaminant levels. In the expanded view you can see each know test date for a given contaminant, the result of the test, the minimum level that can be recognized in a test (MRL), and upper limit that is considered healthy (HRL).

HAA5

Year Test Date MRL HRL Test Result
2018 2018-03-07 0 0.00 13.2

HAA6Br

Year Test Date MRL HRL Test Result
2018 2018-03-07 0 0.00 18.6

HAA9

Year Test Date MRL HRL Test Result
2018 2018-03-07 0 0.00 26.5

1-butanol

Year Test Date MRL HRL Test Result
2018 2018-06-13 2 0.00 < 2
2018 2018-06-13 2 0.00 < 2
2018 2018-03-07 2 0.00 < 2
2018 2018-03-07 2 0.00 < 2

2-methoxyethanol

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.4 0.00 < 0.4
2018 2018-06-13 0.4 0.00 < 0.4
2018 2018-03-07 0.4 0.00 < 0.4
2018 2018-03-07 0.4 0.00 < 0.4

2-propen-1-ol

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.5 0.00 < 0.5
2018 2018-06-13 0.5 0.00 < 0.5
2018 2018-03-07 0.5 0.00 < 0.5
2018 2018-03-07 0.5 0.00 < 0.5

alpha-hexachlorocyclohexane

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.01 0.00 < 0.01
2018 2018-06-13 0.01 0.00 < 0.01
2018 2018-03-07 0.01 0.00 < 0.01
2018 2018-03-07 0.01 0.00 < 0.01

butylated hydroxyanisole

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.03 0.00 < 0.03
2018 2018-06-13 0.03 0.00 < 0.03
2018 2018-03-07 0.03 0.00 < 0.03
2018 2018-03-07 0.03 0.00 < 0.03

chlorpyrifos

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.03 0.00 < 0.03
2018 2018-06-13 0.03 0.00 < 0.03
2018 2018-03-07 0.03 0.00 < 0.03
2018 2018-03-07 0.03 0.00 < 0.03

dimethipin

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.2 0.00 < 0.2
2018 2018-06-13 0.2 0.00 < 0.2
2018 2018-03-07 0.2 0.00 < 0.2
2018 2018-03-07 0.2 0.00 < 0.2

ethoprop

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.03 0.00 < 0.03
2018 2018-06-13 0.03 0.00 < 0.03
2018 2018-03-07 0.03 0.00 < 0.03
2018 2018-03-07 0.03 0.00 < 0.03

germanium

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.3 0.00 < 0.3
2018 2018-06-13 0.3 0.00 < 0.3
2018 2018-03-07 0.3 0.00 < 0.3
2018 2018-03-07 0.3 0.00 < 0.3

manganese

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.4 0.00 1.1
2018 2018-06-13 0.4 0.00 2.8
2018 2018-03-07 0.4 0.00 2.4
2018 2018-03-07 0.4 0.00 2.6

o-toluidine

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.007 0.00 < 0.007
2018 2018-06-13 0.007 0.00 < 0.007
2018 2018-03-07 0.007 0.00 < 0.007
2018 2018-03-07 0.007 0.00 < 0.007

oxyfluorfen

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.05 0.00 < 0.05
2018 2018-06-13 0.05 0.00 < 0.05
2018 2018-03-07 0.05 0.00 < 0.05
2018 2018-03-07 0.05 0.00 < 0.05

profenofos

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.3 0.00 < 0.3
2018 2018-06-13 0.3 0.00 < 0.3
2018 2018-03-07 0.3 0.00 < 0.3
2018 2018-03-07 0.3 0.00 < 0.3

quinoline

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.02 0.00 < 0.02
2018 2018-06-13 0.02 0.00 < 0.02
2018 2018-03-07 0.02 0.00 < 0.02
2018 2018-03-07 0.02 0.00 < 0.02

tebuconazole

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.2 0.00 < 0.2
2018 2018-06-13 0.2 0.00 < 0.2
2018 2018-03-07 0.2 0.00 < 0.2
2018 2018-03-07 0.2 0.00 < 0.2

total permethrin

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.04 0.00 < 0.04
2018 2018-06-13 0.04 0.00 < 0.04
2018 2018-03-07 0.04 0.00 < 0.04
2018 2018-03-07 0.04 0.00 < 0.04

tribufos

Year Test Date MRL HRL Test Result
2018 2018-06-13 0.07 0.00 < 0.07
2018 2018-06-13 0.07 0.00 < 0.07
2018 2018-03-07 0.07 0.00 < 0.07
2018 2018-03-07 0.07 0.00 < 0.07

Other Water Contaminants Tested


The following contaminants were tested and within national EPA guidelines.

Contaminant MRL HRL Avg Result
chlorate 20 210 36.5 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 20 210 67
2014 2014-08-13 20 210 < 20
2014 2014-08-13 20 210 74
2014 2014-05-14 20 210 51
2014 2014-05-14 20 210 < 20
2014 2014-05-14 20 210 49
2014 2014-02-12 20 210 46
2014 2014-02-12 20 210 < 20
2014 2014-02-12 20 210 49
2013 2013-11-18 20 210 50
2013 2013-11-18 20 210 < 20
2013 2013-11-18 20 210 52
chromium 0.2 100 0.1633 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.2 100 < 0.2
2014 2014-08-13 0.2 100 0.38
2014 2014-08-13 0.2 100 < 0.2
2014 2014-05-14 0.2 100 < 0.2
2014 2014-05-14 0.2 100 0.55
2014 2014-05-14 0.2 100 < 0.2
2014 2014-02-12 0.2 100 < 0.2
2014 2014-02-12 0.2 100 0.66
2014 2014-02-12 0.2 100 < 0.2
2013 2013-11-18 0.2 100 < 0.2
2013 2013-11-18 0.2 100 0.37
2013 2013-11-18 0.2 100 < 0.2
chromium-6 0.03 0 0.2207 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.03 0 0.089
2014 2014-08-13 0.03 0 0.42
2014 2014-08-13 0.03 0 0.032
2014 2014-05-14 0.03 0 0.099
2014 2014-05-14 0.03 0 0.54
2014 2014-05-14 0.03 0 0.033
2014 2014-02-12 0.03 0 0.042
2014 2014-02-12 0.03 0 0.66
2014 2014-02-12 0.03 0 < 0.03
2013 2013-11-18 0.03 0 0.19
2013 2013-11-18 0.03 0 0.45
2013 2013-11-18 0.03 0 0.093
cobalt 1 70 < 1 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 1 70 < 1
2014 2014-08-13 1 70 < 1
2014 2014-08-13 1 70 < 1
2014 2014-05-14 1 70 < 1
2014 2014-05-14 1 70 < 1
2014 2014-05-14 1 70 < 1
2014 2014-02-12 1 70 < 1
2014 2014-02-12 1 70 < 1
2014 2014-02-12 1 70 < 1
2013 2013-11-18 1 70 < 1
2013 2013-11-18 1 70 < 1
2013 2013-11-18 1 70 < 1
molybdenum 1 40 4.2 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 1 40 4.6
2014 2014-08-13 1 40 5.1
2014 2014-08-13 1 40 4.7
2014 2014-05-14 1 40 4.3
2014 2014-05-14 1 40 4.1
2014 2014-05-14 1 40 4.6
2014 2014-02-12 1 40 4.6
2014 2014-02-12 1 40 3.8
2014 2014-02-12 1 40 4.4
2013 2013-11-18 1 40 4
2013 2013-11-18 1 40 2
2013 2013-11-18 1 40 4.2
strontium 0.3 1500 711.6667 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.3 1500 980
2014 2014-08-13 0.3 1500 350
2014 2014-08-13 0.3 1500 1100
2014 2014-05-14 0.3 1500 910
2014 2014-05-14 0.3 1500 300
2014 2014-05-14 0.3 1500 1000
2014 2014-02-12 0.3 1500 1100
2014 2014-02-12 0.3 1500 290
2014 2014-02-12 0.3 1500 1000
2013 2013-11-18 0.3 1500 620
2013 2013-11-18 0.3 1500 170
2013 2013-11-18 0.3 1500 720
vanadium 0.2 21 2.9583 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.2 21 3.1
2014 2014-08-13 0.2 21 4.4
2014 2014-08-13 0.2 21 2.9
2014 2014-05-14 0.2 21 2.6
2014 2014-05-14 0.2 21 3.6
2014 2014-05-14 0.2 21 2.4
2014 2014-02-12 0.2 21 2.3
2014 2014-02-12 0.2 21 3.3
2014 2014-02-12 0.2 21 2.2
2013 2013-11-18 0.2 21 2.7
2013 2013-11-18 0.2 21 3.4
2013 2013-11-18 0.2 21 2.6
1,1-dichloroethane 0.03 6.14 < 0.03 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.03 6.14 < 0.03
2014 2014-08-13 0.03 6.14 < 0.03
2014 2014-05-14 0.03 6.14 < 0.03
2014 2014-05-14 0.03 6.14 < 0.03
2014 2014-02-12 0.03 6.14 < 0.03
2014 2014-02-12 0.03 6.14 < 0.03
2013 2013-11-18 0.03 6.14 < 0.03
2013 2013-11-18 0.03 6.14 < 0.03
1,2,3-trichloropropane 0.03 0.0004 < 0.03 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.03 0.0004 < 0.03
2014 2014-08-13 0.03 0.0004 < 0.03
2014 2014-05-14 0.03 0.0004 < 0.03
2014 2014-05-14 0.03 0.0004 < 0.03
2014 2014-02-12 0.03 0.0004 < 0.03
2014 2014-02-12 0.03 0.0004 < 0.03
2013 2013-11-18 0.03 0.0004 < 0.03
2013 2013-11-18 0.03 0.0004 < 0.03
1,3-butadiene 0.1 0.0103 < 0.1 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.1 0.0103 < 0.1
2014 2014-08-13 0.1 0.0103 < 0.1
2014 2014-05-14 0.1 0.0103 < 0.1
2014 2014-05-14 0.1 0.0103 < 0.1
2014 2014-02-12 0.1 0.0103 < 0.1
2014 2014-02-12 0.1 0.0103 < 0.1
2013 2013-11-18 0.1 0.0103 < 0.1
2013 2013-11-18 0.1 0.0103 < 0.1
1,4-dioxane 0.07 0.35 < 0.07 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.07 0.35 < 0.07
2014 2014-08-13 0.07 0.35 < 0.07
2014 2014-05-14 0.07 0.35 < 0.07
2014 2014-05-14 0.07 0.35 < 0.07
2014 2014-02-12 0.07 0.35 < 0.07
2014 2014-02-12 0.07 0.35 < 0.07
2013 2013-11-18 0.07 0.35 < 0.07
2013 2013-11-18 0.07 0.35 < 0.07
17-alpha-ethynylestradiol 0.0009 0.035 < 0.0009 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.0009 0.035 < 0.0009
2014 2014-08-13 0.0009 0.035 < 0.0009
2014 2014-05-14 0.0009 0.035 < 0.0009
2014 2014-05-14 0.0009 0.035 < 0.0009
2014 2014-02-12 0.0009 0.035 < 0.0009
2014 2014-02-12 0.0009 0.035 < 0.0009
2013 2013-11-18 0.0009 0.035 < 0.0009
2013 2013-11-18 0.0009 0.035 < 0.0009
17-beta-estradiol 0.0004 0.0009 < 0.0004 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.0004 0.0009 < 0.0004
2014 2014-08-13 0.0004 0.0009 < 0.0004
2014 2014-05-14 0.0004 0.0009 < 0.0004
2014 2014-05-14 0.0004 0.0009 < 0.0004
2014 2014-02-12 0.0004 0.0009 < 0.0004
2014 2014-02-12 0.0004 0.0009 < 0.0004
2013 2013-11-18 0.0004 0.0009 < 0.0004
2013 2013-11-18 0.0004 0.0009 < 0.0004
4-androstene-3,17-dione 0.0003 0 0.0001 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.0003 0 < 0.0003
2014 2014-08-13 0.0003 0 < 0.0003
2014 2014-05-14 0.0003 0 < 0.0003
2014 2014-05-14 0.0003 0 < 0.0003
2014 2014-02-12 0.0003 0 < 0.0003
2014 2014-02-12 0.0003 0 0.00041
2013 2013-11-18 0.0003 0 < 0.0003
2013 2013-11-18 0.0003 0 < 0.0003
bromomethane 0.2 140 < 0.2 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.2 140 < 0.2
2014 2014-08-13 0.2 140 < 0.2
2014 2014-05-14 0.2 140 < 0.2
2014 2014-05-14 0.2 140 < 0.2
2014 2014-02-12 0.2 140 < 0.2
2014 2014-02-12 0.2 140 < 0.2
2013 2013-11-18 0.2 140 < 0.2
2013 2013-11-18 0.2 140 < 0.2
chloromethane 0.2 2.69 < 0.2 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.2 2.69 < 0.2
2014 2014-08-13 0.2 2.69 < 0.2
2014 2014-05-14 0.2 2.69 < 0.2
2014 2014-05-14 0.2 2.69 < 0.2
2014 2014-02-12 0.2 2.69 < 0.2
2014 2014-02-12 0.2 2.69 < 0.2
2013 2013-11-18 0.2 2.69 < 0.2
2013 2013-11-18 0.2 2.69 < 0.2
equilin 0.004 0.35 < 0.004 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.004 0.35 < 0.004
2014 2014-08-13 0.004 0.35 < 0.004
2014 2014-05-14 0.004 0.35 < 0.004
2014 2014-05-14 0.004 0.35 < 0.004
2014 2014-02-12 0.004 0.35 < 0.004
2014 2014-02-12 0.004 0.35 < 0.004
2013 2013-11-18 0.004 0.35 < 0.004
2013 2013-11-18 0.004 0.35 < 0.004
estriol 0.0008 0.35 < 0.0008 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.0008 0.35 < 0.0008
2014 2014-08-13 0.0008 0.35 < 0.0008
2014 2014-05-14 0.0008 0.35 < 0.0008
2014 2014-05-14 0.0008 0.35 < 0.0008
2014 2014-02-12 0.0008 0.35 < 0.0008
2014 2014-02-12 0.0008 0.35 < 0.0008
2013 2013-11-18 0.0008 0.35 < 0.0008
2013 2013-11-18 0.0008 0.35 < 0.0008
estrone 0.002 0.35 < 0.002 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.002 0.35 < 0.002
2014 2014-08-13 0.002 0.35 < 0.002
2014 2014-05-14 0.002 0.35 < 0.002
2014 2014-05-14 0.002 0.35 < 0.002
2014 2014-02-12 0.002 0.35 < 0.002
2014 2014-02-12 0.002 0.35 < 0.002
2013 2013-11-18 0.002 0.35 < 0.002
2013 2013-11-18 0.002 0.35 < 0.002
Halon 1011 0.06 90 < 0.06 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.06 90 < 0.06
2014 2014-08-13 0.06 90 < 0.06
2014 2014-05-14 0.06 90 < 0.06
2014 2014-05-14 0.06 90 < 0.06
2014 2014-02-12 0.06 90 < 0.06
2014 2014-02-12 0.06 90 < 0.06
2013 2013-11-18 0.06 90 < 0.06
2013 2013-11-18 0.06 90 < 0.06
HCFC-22 0.08 0 < 0.08 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.08 0 < 0.08
2014 2014-08-13 0.08 0 < 0.08
2014 2014-05-14 0.08 0 < 0.08
2014 2014-05-14 0.08 0 < 0.08
2014 2014-02-12 0.08 0 < 0.08
2014 2014-02-12 0.08 0 < 0.08
2013 2013-11-18 0.08 0 < 0.08
2013 2013-11-18 0.08 0 < 0.08
PFBS 0.09 0 < 0.09 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.09 0 < 0.09
2014 2014-08-13 0.09 0 < 0.09
2014 2014-05-14 0.09 0 < 0.09
2014 2014-05-14 0.09 0 < 0.09
2014 2014-02-12 0.09 0 < 0.09
2014 2014-02-12 0.09 0 < 0.09
2013 2013-11-18 0.09 0 < 0.09
2013 2013-11-18 0.09 0 < 0.09
PFHpA 0.01 0 < 0.01 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.01 0 < 0.01
2014 2014-08-13 0.01 0 < 0.01
2014 2014-05-14 0.01 0 < 0.01
2014 2014-05-14 0.01 0 < 0.01
2014 2014-02-12 0.01 0 < 0.01
2014 2014-02-12 0.01 0 < 0.01
2013 2013-11-18 0.01 0 < 0.01
2013 2013-11-18 0.01 0 < 0.01
PFHxS 0.03 0 < 0.03 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.03 0 < 0.03
2014 2014-08-13 0.03 0 < 0.03
2014 2014-05-14 0.03 0 < 0.03
2014 2014-05-14 0.03 0 < 0.03
2014 2014-02-12 0.03 0 < 0.03
2014 2014-02-12 0.03 0 < 0.03
2013 2013-11-18 0.03 0 < 0.03
2013 2013-11-18 0.03 0 < 0.03
PFNA 0.02 0 < 0.02 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.02 0 < 0.02
2014 2014-08-13 0.02 0 < 0.02
2014 2014-05-14 0.02 0 < 0.02
2014 2014-05-14 0.02 0 < 0.02
2014 2014-02-12 0.02 0 < 0.02
2014 2014-02-12 0.02 0 < 0.02
2013 2013-11-18 0.02 0 < 0.02
2013 2013-11-18 0.02 0 < 0.02
PFOA 0.02 0.07 < 0.02 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.02 0.07 < 0.02
2014 2014-08-13 0.02 0.07 < 0.02
2014 2014-05-14 0.02 0.07 < 0.02
2014 2014-05-14 0.02 0.07 < 0.02
2014 2014-02-12 0.02 0.07 < 0.02
2014 2014-02-12 0.02 0.07 < 0.02
2013 2013-11-18 0.02 0.07 < 0.02
2013 2013-11-18 0.02 0.07 < 0.02
PFOS 0.04 0.07 < 0.04 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.04 0.07 < 0.04
2014 2014-08-13 0.04 0.07 < 0.04
2014 2014-05-14 0.04 0.07 < 0.04
2014 2014-05-14 0.04 0.07 < 0.04
2014 2014-02-12 0.04 0.07 < 0.04
2014 2014-02-12 0.04 0.07 < 0.04
2013 2013-11-18 0.04 0.07 < 0.04
2013 2013-11-18 0.04 0.07 < 0.04
testosterone 0.0001 0 < 0.0001 [+] Expand Test Data
Year Test Date MRL HRL Test Result
2014 2014-08-13 0.0001 0 < 0.0001
2014 2014-08-13 0.0001 0 < 0.0001
2014 2014-05-14 0.0001 0 < 0.0001
2014 2014-05-14 0.0001 0 < 0.0001
2014 2014-02-12 0.0001 0 < 0.0001
2014 2014-02-12 0.0001 0 < 0.0001
2013 2013-11-18 0.0001 0 < 0.0001
2013 2013-11-18 0.0001 0 < 0.0001

Lead and Copper Data


Lead and copper are recorded separately from other contaminants because of the Lead and Copper Rule. As with all other results, these are the findings at the water supply. Lead and copper can be — and often are — added to drinking water in between the water facility and a tap.

Sample ID Contaminant Sampling Start Date Sampling End Date Result
CA63948 lead 2016-01-01 2018-12-31 0.00423mg/L
CA49187 lead 2013-01-01 2015-12-31 0mg/L
191023412214LT5 lead 2012-01-01 2012-12-31 0.002mg/L
CA38785 lead 2010-01-01 2012-12-31 0.002mg/L
191023410168L6M2ND-1 lead 2010-01-01 2010-12-31 0.006mg/L
191023410175LT4 lead 2010-01-01 2010-12-31 0.003mg/L
191023410244LT3 lead 2010-01-01 2010-12-31 0.002mg/L
191023410246LT1 lead 2010-01-01 2010-12-31 0.005mg/L
191023410260LT2 lead 2010-01-01 2010-12-31 0.003mg/L
191023409211LT4 lead 2009-01-01 2009-12-31 0.003mg/L

Violations


Known violations of the Safe Drinking Water Act as recorded by the EPA.

Compliance Dates Rule Violation Type Contaminant Name Status
- N/A Total Coliform Rule Maximum Contaminant Level Violation, Monthly (TCR) Coliform (TCR) Returned to Compliance

What My Water Data Means


Water data isn't always easy to interpret, but by following the links on this page you should be able to have most of your questions answered. By clicking the name of a water contaminant or secondary substance you can learn about that specific substance. Ultimately this page should give you some insight towards learning if your water is safe, what water filter you should buy (if any), and how well your local water compares against other sources.

Sources


The origin of MyTapWater.org's water data is explained on our Data Sources page.

Why Is My Water Data Not More Recent?


The recency of the data for your ZIP code depends on the last your water source was tested, by a federal, state, or local agency. More information about the timing can be determined by learning about the dataset in question and seeing how often the EPA (other another governing body) mandated testing.