The Power of Information

National Drinking Water Database


Woonsocket Water Department Utilities - Providence, RI


Serves 46,000 people

Chloroform

Chloroform is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
11 days
Test Days Exceeding Legal LimitsNumber of days in which the samples taken in that day exceed the Maximum Contaminant Level (Depending on the contaminant and its MCL, that may or may not trigger an MCL violation. Some MCLs are based on averages spanning several months to a year)
1 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
27 days
Tests ConductedNumber of individual tests done for this contaminant
39 tests

Testing Summary

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
ChloroformChloroform is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.12.17 ppb
86 ppb
Yes
5.7 ppb
Yes
80 ppb
NOTE: Each dot in the above graph represents one month.
* Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.

Health Based and Legal Limits for Chloroform

Health Based Limits for Chloroform

StandardDescriptionLevel
EPA Human Health Water Quality CriteriaWater quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.5.7 ppb
Drinking Water Equivalent LevelA lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.35 ppb
Maximum Contaminant Limit Goal (MCLG)A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.70 ppb
Lifetime health-based limit, non-cancer riskConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency.70 ppb
Maximum Contaminant Limit (MCL)The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.80 ppb
Children's health-based limit for 1-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.4000 ppb
Children's health-based limit for 10-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.4000 ppb

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2009-03-250 ppb220 ppb
2008-04-070 ppb110 ppb
2008-01-280 ppb220 ppb
2007-10-3031 ppb1031 ppb
2007-10-2437 ppb1037 ppb
2007-05-210 ppb110 ppb
2007-03-050 ppb220 ppb
2006-08-1116 ppb1016 ppb
2006-06-2086 ppb1086 ppb
2006-04-180 ppb110 ppb
2006-02-070 ppb220 ppb
2005-05-160 ppb220 ppb
2005-02-140 ppb220 ppb
2004-12-1435.4 ppb1035.4 ppb
2004-12-0612 ppb1012 ppb
2004-11-1012.6 ppb1012.6 ppb
2004-10-200 ppb110 ppb
2004-10-1913 ppb1013 ppb
2004-09-2750.2 ppb206.4 to 94 ppb
2004-09-1515.1 ppb2011 to 19.2 ppb
2004-08-020 ppb110 ppb
2004-06-210 ppb110 ppb
2004-05-1812.75 ppb208.7 to 16.8 ppb
2004-05-054.4 ppb104.4 ppb
2004-05-040.93 ppb320 to 2.8 ppb
2004-03-230 ppb110 ppb
2004-02-252.15 ppb201.5 to 2.8 ppb