The Power of Information

National Drinking Water Database


Tewksbury Water Dept Utilities - Cambridge, MA


Serves 29,770 people

Chlorite

Chlorite is a disinfection byproduct resulting from water treatment with chlorine dioxide, or from the use of chlorine dioxide as a bleaching agent for cellulose, paper pulp, flour and oils.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
0 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)
0 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
54 days
Tests ConductedNumber of individual tests done for this contaminant
156 tests

Testing Summary

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
ChloriteChlorite is a disinfection byproduct resulting from water treatment with chlorine dioxide, or from the use of chlorine dioxide as a bleaching agent for cellulose, paper pulp, flour and oils.52.83 ppb
290 ppb
No
800 ppb
No
1000 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 Chlorite

Health Based Limits for Chlorite

StandardDescriptionLevel
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.800 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.800 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.840 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.840 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.1000 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.1000 ppb

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2009-04-06150 ppb30130 to 170 ppb
2009-03-10230 ppb30220 to 240 ppb
2009-02-05160 ppb30140 to 180 ppb
2009-01-1382 ppb3060 to 94 ppb
2008-12-0329 ppb3021 to 44 ppb
2008-11-050 ppb330 ppb
2008-10-140 ppb330 ppb
2008-09-080 ppb330 ppb
2008-08-120 ppb330 ppb
2007-11-0828.67 ppb3024 to 37 ppb
2007-10-090 ppb330 ppb
2007-09-110 ppb330 ppb
2007-08-090 ppb330 ppb
2007-07-100 ppb330 ppb
2007-06-050 ppb330 ppb
2007-05-0930.67 ppb3011 to 41 ppb
2007-04-10108.33 ppb3095 to 120 ppb
2007-03-0764 ppb3052 to 87 ppb
2007-02-0687.67 ppb3086 to 91 ppb
2007-01-0951.67 ppb3025 to 90 ppb
2006-12-0525.33 ppb3017 to 30 ppb
2006-11-0724 ppb3022 to 27 ppb
2006-10-030 ppb330 ppb
2006-09-130 ppb330 ppb
2006-08-150 ppb330 ppb
2006-07-120 ppb330 ppb
2006-06-060 ppb330 ppb
2006-05-044.33 ppb320 to 13 ppb
2006-04-0543.33 ppb3034 to 48 ppb
2006-03-0883 ppb3074 to 91 ppb
2006-02-0878.67 ppb3076 to 84 ppb
2006-01-1776.67 ppb3071 to 85 ppb
2005-12-0645.33 ppb3044 to 48 ppb
2005-10-0411.67 ppb3010 to 14 ppb
2005-09-130 ppb330 ppb
2005-08-020 ppb330 ppb
2005-07-0546.67 ppb3037 to 61 ppb
2005-06-0739.67 ppb3033 to 46 ppb
2005-05-03140 ppb30120 to 150 ppb
2005-04-0559.67 ppb3054 to 68 ppb
2005-03-02140 ppb30130 to 150 ppb
2005-02-03136.67 ppb30110 to 160 ppb
2005-01-27119.33 ppb3098 to 140 ppb
2004-12-0756.33 ppb3032 to 81 ppb
2004-11-0931 ppb3026 to 34 ppb
2004-10-200 ppb110 ppb
2004-10-190 ppb220 ppb
2004-08-039 ppb310 to 14 ppb
2004-07-083.67 ppb320 to 11 ppb
2004-06-2332 ppb3012 to 55 ppb
2004-04-2720 ppb310 to 34 ppb
2004-03-0999.33 ppb3078 to 110 ppb
2004-02-19290 ppb10290 ppb
2004-02-18215 ppb20200 to 230 ppb