The Power of Information

National Drinking Water Database


Newport Water District Utilities - Orono, ME


Serves 1,590 people

Total trihalomethanes (TTHMs)

Total trihalomethanes constitute the sum of four disinfection byproducts: chloroform, bromodichloromethane, dibromochloromethane, and bromoform.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
25 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)
20 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
25 days
Tests ConductedNumber of individual tests done for this contaminant
32 tests

Testing Summary

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
Total trihalomethanes (TTHMs)Total trihalomethanes constitute the sum of four disinfection byproducts: chloroform, bromodichloromethane, dibromochloromethane, and bromoform.131.85 ppb
224 ppb
Yes
9.8 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 Total trihalomethanes (TTHMs)

Health Based Limits for Total trihalomethanes (TTHMs)

StandardDescriptionLevel
One in one million (10-6) Cancer RiskThe concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 1,000,000. Source: U.S. Environmental Protection Agency.9.8 ppb
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.11.5 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
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.130 ppb
One in ten thousand (10-4) Cancer RiskThe concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 10,000. Source: U.S. Environmental Protection Agency.980 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.1835 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.4860 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.10600 ppb

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2009-04-13144 ppb10144 ppb
2009-03-17195 ppb10195 ppb
2009-03-06215 ppb20205 to 225 ppb
2008-12-02179 ppb20163 to 195 ppb
2008-10-20143 ppb10143 ppb
2008-05-20143 ppb10143 ppb
2008-03-1932.9 ppb3032.9 ppb
2008-02-1996 ppb1096 ppb
2007-10-16125 ppb10125 ppb
2007-07-18205 ppb10205 ppb
2007-04-25174 ppb10174 ppb
2007-02-2164.5 ppb1064.5 ppb
2006-11-08133 ppb10133 ppb
2006-08-09124 ppb10124 ppb
2006-05-22113 ppb10113 ppb
2006-03-14132 ppb10132 ppb
2005-11-16224 ppb10224 ppb
2005-08-24154 ppb10154 ppb
2005-06-1454.9 ppb3054.9 ppb
2005-05-1766 ppb1066 ppb
2005-01-1834 ppb1034 ppb
2004-12-13101 ppb10101 ppb
2004-09-13124 ppb10124 ppb
2004-05-18170 ppb10170 ppb
2004-03-15150 ppb20140 to 160 ppb