How Do I Read This Table

It’s easy! Our water is tested to assure that it is safe and healthy. The column marked Detected Level shows the highest test results during the year. The column marked Major Sources in Drinking Water shows where substances usually originate. Footnotes explain important details. Abbreviations and definitions of key terms are shown in the table below:

AL	Action Level: The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow.
MCL	Maximum Contaminant Level: The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.
MCLG	Maximum Contaminant Level Goal: The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.
MRDL	Maximum Residual Disinfectant Level: The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
MRDLG	Maximum Residual Disinfectant Level Goal: The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.
mrem	Millirems: a measure of radiation absorbed by the body.
N/A	Not Applicable.
ND	Not Detectable: Not detectable at testing limits.
NTU	Nephelometric Turbidity Units: a measure of very small particulate matter in drinking water.
pCi/l	Picocuries per liter: a measure of radioactivity.
ppb	parts per billion, or micrograms per liter (μg/l).
ppm	parts per million, or milligrams per liter (mg/l).
ppt	parts per trillion, or nanograms per liter (nanograms/l)
TT	Treatment Technique: A required process intended to reduce the level of a contaminant in drinking water.

2005 WATER QUALITY TABLE *
CONTAMINANT (footnote)	YEAR TESTED	UNIT	MCL / MRDL	MCLG / MRDLG	DETECTED LEVEL	RANGE	MAJOR SOURCES IN DRINKING WATER	VIOLA-TION
Microorganisms			MCL	MCLG
Total Coliform Bacteria (8)	2005	# of Positive Samples	Two or more positive samples in one month	0	1	N/A	Naturally present in the environment.	NO
Turbidity (1) (7)	2005	NTU	TT = 1.0	N/A	0.28	N/A	Soil runoff.	NO
Turbidity (1) (7)	2005	NTU	TT = 95% of monthly samples < 0.3	N/A	100.00% < 0.3	N/A	Soil runoff.	NO
Total organic carbon (1)	2005	Removal ratio	TT	N/A	1.06	0.82 – 1.22	Naturally present in the environment.	NO
Disinfection Byproducts			MCL	MCLG
Chlorite (1)	2005	ppm	1.0	0.8	0.327	0.085 – 0.342	By-product of drinking water chlorination.	NO
Haloacetic acids (HAA5s)	2005	ppb	60	N/A	27.5	9.6 – 33.2	By-product of drinking water chlorination.	NO
Total Trihalomethanes (TTHMs) (6)	2005	ppb	80	N/A	75.6	49.9 – 103	By-product of drinking water chlorination.	NO
Disinfectants			MRDL	MRDLG
Chlorine	2005	ppm	4	4	0.71	0.03 – 1.72	Water additive used to control microbes.	NO
Chlorine dioxide (1)	2005	ppb	800	800	710	60 – 710	Water additive used to control microbes.	NO
Inorganic Chemicals			MCL	MCLG
Copper (3)	2005	ppm	AL = 1.3	1.3	0.092	N/A	Corrosion of household plumbing systems; erosion of natural deposits; leaching from wood preservatives.	NO
Fluoride (1) (4)	2005	ppm	4	4	1.31	0.81 – 1.31	Water additive, which promotes strong teeth.	NO
Lead (5)	2005	ppb	AL = 15	0	24	N/A	Corrosion of household plumbing systems; erosion of natural deposits.	NO
Nitrate (2)	2005	ppm	10	10	1.81	0.49 – 1.81	Runoff from fertilizer use; leaching from septic tanks, sewerage; erosion of natural deposits.	NO
Synthetic Organic Chemicals including Pesticides and Herbicides			MCL	MCLG
Simazine (2)	2005	ppb	4	4	0.15	ND – 0.15	Herbicide runoff.	NO
Radionuclides			MCL	MCLG
Beta/photon emitters (2)	2001	pCI/L	50 **	0	3.69	1.85 – 3.69	Decay of natural and man-made deposits.	NO
Combined radium (2)	2001	pCI/L	5	0	2.18	ND – 2.18	Erosion of natural deposits.	NO
Unregulated Chemicals			MCL	MCLG
Sodium (1)	2005	ppm	100 ***	N/A	22.9	16.6 – 22.9	Erosion of natural deposits; road-salt runoff; contained in water treatment chemicals.	N/A

* The data presented in this table is from the most recent testing done in accordance with regulations. Test results are from the Portsmouth Water and Fire District's distribution system unless otherwise noted by the footnotes.

** The MCL for beta particles is 4 mrem/year. EPA considers 50 pCi/l to be the level of concern for beta particles.

*** Although not regulated by the EPA, we are required by the Rhode Island Department of Health to test for sodium. There is no MCL for sodium, however the Health Advisory Level is 100 ppm.

NOTE: The state allows us to monitor for some contaminants less than once per year because the concentrations of these contaminants do not change frequently. Some of our data, though representative, are more than one year old.

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