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EWG's Tap Water Database — 2019 UPDATE

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Total trihalomethanes (TTHMs)

Marine Corps Base Hawaii

NOTE: Marine Corps Base Hawaii purchases water from Honolulu-Windward-Pearl Harbor which is required to test for total trihalomethanes (tthms). Sample information shown below was taken by Honolulu-Windward-Pearl Harbor.

Trihalomethanes are cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform. Read More.

Studies conducted in the U.S. and Europe have found that drinking tap water that carries disinfection byproducts increases the risk of developing bladder cancer. In animal studies, all trihalomethanes cause liver, kidney and intestinal tumors. Some human epidemiological studies also reported an association between disinfection byproducts and an increased risk of problems during pregnancy, including spontaneous miscarriage, cardiovascular defects, neural tube defects and low birth weight.

The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.

Click here to read more about disinfection byproducts.

 

262

Samples

0

Samples exceeding legal limit (MCL)

124

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20123.10 ppb441.30 ppb - 5.60 ppb
20132.28 ppb3521ND - 12.0 ppb
20142.14 ppb880.800 ppb - 4.30 ppb
20152.54 ppb16160.800 ppb - 7.10 ppb
20162.35 ppb21ND - 4.70 ppb
20172.30 ppb221.50 ppb - 3.10 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.15 ppb

The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.

EPA Maximum Contaminant
Level (MCL) 80 ppb

The legal limit for the group of four trihalomethanes, established in 1998, was based on the need for residual disinfectant levels in water served to customers and the cost of treatment. This limit does not fully protect against the risk of cancer due to exposure to trihalomethanes.

ppb = parts per billion

All test results

NOTE: Marine Corps Base Hawaii purchases water from Honolulu-Windward-Pearl Harbor which is required to test for total trihalomethanes (tthms). Sample information shown below was taken by Honolulu-Windward-Pearl Harbor.

Date Lab ID Result
2012-05-22201205240274ND
2012-06-132012061602201.70 ppb
2012-06-132012061602213.90 ppb
2012-06-132012061602273.60 ppb
2012-06-13201206160223ND
2012-06-132012061602243.00 ppb
2012-06-132012061602260.910 ppb
2012-06-18201206200496ND
2012-06-202012062102970.600 ppb
2012-09-042012090606261.40 ppb
2012-09-042012090606250.720 ppb
2012-09-112012091401101.90 ppb
2012-09-112012091401092.00 ppb
2012-09-112012091401131.30 ppb
2012-09-112012091401140.500 ppb
2012-09-112012091401150.510 ppb
2012-09-112012091401161.20 ppb
2012-09-112012091401114.90 ppb
2012-09-122012091502231.90 ppb
2012-09-172012092001475.00 ppb
2012-09-172012092001464.10 ppb
2012-09-172012092001493.70 ppb
2012-09-172012092001513.60 ppb
2012-11-05201211070127ND
2012-12-102012121302000.960 ppb
2012-12-102012121301344.00 ppb
2012-12-102012121301337.50 ppb
2012-12-112012121401071.80 ppb
2012-12-112012121401083.20 ppb
2012-12-122012121500310.940 ppb
2013-02-19201302210752ND
2013-02-20201302230026ND
2013-02-25201302280066ND
2013-03-112013031403330.830 ppb
2013-03-112013031403372.10 ppb
2013-03-112013031403355.30 ppb
2013-03-112013031403383.70 ppb
2013-03-122013031504497.60 ppb
2013-03-122013031504480.890 ppb
2013-03-27201303290320ND
2013-04-17201304190394ND
2013-04-23201304250517ND
2013-05-08201305100445ND
2013-05-22201305240246ND
2013-06-032013060502610.940 ppb
2013-06-032013060502623.80 ppb
2013-06-042013060603561.40 ppb
2013-06-042013060603601.90 ppb
2013-06-042013060603618.50 ppb
2013-06-04201306060273ND
2013-06-052013060701690.570 ppb
2013-07-31201308020180ND
2013-08-12201308150011ND
2013-09-032013090602090.960 ppb
2013-09-0320130906020812.0 ppb
2013-09-042013090604510.860 ppb
2013-09-042013090604552.00 ppb
2013-09-062013091004963.80 ppb
2013-11-04201311060872ND
2013-11-12201311140801ND
2013-12-022013120413411.20 ppb
2013-12-02201312041342ND
2013-12-0320131205064811.0 ppb
2013-12-032013120506506.90 ppb
2013-12-042013120602403.70 ppb
2014-02-19201402210438ND
2014-03-1020140312066511.0 ppb
2014-03-102014031206620.670 ppb
2014-03-112014031305938.20 ppb
2014-03-112014031305903.50 ppb
2014-03-112014031305921.30 ppb
2014-04-01201404030466ND
2014-04-01201404030469ND
2014-04-01201404030467ND
2014-04-01201404030468ND
2014-04-022014040405520.850 ppb
2014-04-02201404040551ND
2014-04-02201404040553ND
2014-04-02201404040554ND
2014-04-022014040405500.690 ppb
2014-04-04201404080621ND
2014-04-04201404080620ND
2014-04-07201404090485ND
2014-04-07201404090482ND
2014-04-07201404090484ND
2014-04-07201404090483ND
2014-04-08201404100546ND
2014-04-08201404100549ND
2014-04-08201404100547ND
2014-04-08201404100550ND
2014-04-08201404100551ND
2014-04-09201404120256ND
2014-04-09201404120257ND
2014-04-09201404120258ND
2014-04-11201404150363ND
2014-04-142014041605551.60 ppb
2014-04-14201404160552ND
2014-04-14201404160556ND
2014-04-14201404160551ND
2014-04-14201404160553ND
2014-04-14201404160554ND
2014-04-152014041703400.990 ppb
2014-04-15201404170342ND
2014-04-15201404170344ND
2014-04-15201404170341ND
2014-04-16201404180401ND
2014-04-16201404180404ND
2014-04-16201404180402ND
2014-04-16201404180406ND
2014-04-16201404180405ND
2014-04-16201404180403ND
2014-04-21201404230599ND
2014-04-22201404240273ND
2014-04-222014042402741.20 ppb
2014-04-23201404250202ND
2014-04-23201404250201ND
2014-04-28201404300621ND
2014-05-06201405080376ND
2014-06-022014060408110.700 ppb
2014-06-022014060408071.50 ppb
2014-06-0320140607009612.0 ppb
2014-06-032014060701012.20 ppb
2014-06-032014060701007.10 ppb
2014-07-21201407230644ND
2014-08-19201408220168ND
2014-09-09201409120804ND
2014-09-1020140912079812.0 ppb
2014-09-102014091208073.90 ppb
2014-09-102014091208092.20 ppb
2014-09-102014091207991.20 ppb
2014-12-012014120403640.530 ppb
2014-12-022014120403865.10 ppb
2014-12-022014120403872.00 ppb
2014-12-032014120503231.30 ppb
2014-12-032014120503224.10 ppb
2015-01-062015010803934.70 ppb
2015-01-062015010803941.10 ppb
2015-01-062015010804002.30 ppb
2015-01-062015010804032.90 ppb
2015-01-132015011505855.80 ppb
2015-02-09201502110395ND
2015-02-102015021202760.670 ppb
2015-04-012015040302441.20 ppb
2015-04-062015040802957.50 ppb
2015-04-062015040802962.30 ppb
2015-04-082015041001591.20 ppb
2015-04-082015041001606.50 ppb
2015-04-13201504140137ND
2015-04-20201504210283ND
2015-05-04201505060108ND
2015-05-27201505290083ND
2015-07-072015070801630.520 ppb
2015-07-08201507100093ND
2015-07-0920150710011111.0 ppb
2015-07-092015071001122.80 ppb
2015-07-132015071505801.20 ppb
2015-07-132015071505814.60 ppb
2015-08-18201508200479ND
2015-10-052015100701940.950 ppb
2015-10-052015100701961.000 ppb
2015-10-062015091601112.90 ppb
2015-10-062015091601126.80 ppb
2015-10-07201509160110ND
2015-10-19201510140073ND
2015-12-28201512180363ND
2016-01-051.10 ppb
2016-01-063.10 ppb
2016-01-12ND
2016-01-122.70 ppb
2016-01-12ND
2016-02-092.60 ppb
2016-04-111.40 ppb
2016-04-114.30 ppb
2016-04-11ND
2016-04-132.50 ppb
2016-04-13ND
2016-04-190.700 ppb
2016-05-02ND
2016-05-04ND
2016-07-052.40 ppb
2016-07-051.10 ppb
2016-07-054.60 ppb
2016-07-06ND
2016-07-11ND
2016-10-033.60 ppb
2016-10-04ND
2016-10-051.70 ppb
2016-10-141.20 ppb
2016-10-145.20 ppb
2016-10-28ND
2017-01-030.710 ppb
2017-01-034.70 ppb
2017-01-031.40 ppb
2017-01-172.80 ppb
2017-01-23ND
2017-02-14ND
2017-04-03ND
2017-04-03ND
2017-04-031.90 ppb
2017-04-035.90 ppb
2017-04-05ND
2017-04-05ND
2017-04-0514.0 ppb
2017-04-05ND
2017-04-101.90 ppb
2017-04-11ND
2017-04-11ND
2017-04-11ND
2017-04-11ND
2017-04-17ND
2017-04-17ND
2017-04-18ND
2017-04-18ND
2017-04-19ND
2017-04-19ND
2017-04-19ND
2017-04-19ND
2017-04-19ND
2017-04-19ND
2017-04-20ND
2017-05-01ND
2017-05-01ND
2017-05-020.890 ppb
2017-05-03ND
2017-05-03ND
2017-05-03ND
2017-05-03ND
2017-05-03ND
2017-05-04ND
2017-05-09ND
2017-05-09ND
2017-05-09ND
2017-05-10ND
2017-05-10ND
2017-05-11ND
2017-05-16ND
2017-05-16ND
2017-05-17ND
2017-05-22ND
2017-05-22ND
2017-05-22ND
2017-05-22ND
2017-05-22ND
2017-05-23ND
2017-05-23ND
2017-05-24ND
2017-05-300.670 ppb
2017-06-05ND
2017-06-05ND
2017-06-06ND
2017-06-070.520 ppb
2017-06-13ND
2017-07-03ND
2017-07-102.10 ppb
2017-07-101.60 ppb
2017-07-104.70 ppb
2017-07-10ND
2017-10-032.50 ppb
2017-10-032.10 ppb
2017-10-034.40 ppb
2017-10-03ND
2017-10-050.580 ppb