2007

The source of the Maple Hills water supply are two wells located on Bedard Avenue in Derry, NH.  Well # 5 is located 83 feet northwest of the pump house.  Well # 6 is located 180 feet southwest of the pump house.  Treatment consist of chlorine addition to kill bacteria, aeration to remove radon from the water, 5 micron bag filters for remove sediment from the water and phosphate addition to sequester iron and manganese and control corrosion.
MAPLE HILLS
EPA # 0612020
Inorganic Contaminants	Units	MCLG	MCL	Level Detected	Range	Year	Violation Yes/No	Typical Source of Contaminant
Arsenic	ppb	0	10	6	n/a	2006	NO	Erosion of natural deposits; runoff from orchards; runoff from glass and electronics production wastes.
While your drinking water meets EPA's standard for arsenic, it does contain low levels of arsenic.  EPA's standard balances the current understanding of arsenic's possible health effects against the costs of removing arsenic from drinking water.  EPA continues to research the health effects of low levels of arsenic, which is a mineral know to cause cancer in humans at high concentrations and is linked to other health effects such as skin damage and circulatory problems.
Fluoride	ppm	4	4	0.32	n/a	2006	NO	Erosion of natural deposits
Radiological Contaminants	Units	MCLG	MCL	Level Detected	Range	Year	Violation Yes/No	Typical Source of Contaminant
Gross Alpha (Compliance)	pCi/L	0	15	7.7	1.7 to 7.7	2005	NO	Erosion of natural deposits
Combined Radium	pCi/L	0	5	3.2	1.1 to 3.2	2005	NO	Erosion of natural deposits
Uranium	ppb	0	30	2.1	1.3 to 2.1	2005	NO	Erosion of natural deposits
Radon	pCi/L	Not Regulated		239	nd to 239	2006	n/a	Erosion of natural deposits
Radon is a radioactive gas that you can't see, taste or smell.  It can move up through the ground and into a home through cracks and holes in the foundation.  Radon can also get into indoor air when released from tap water from showering, washing dishes, and other household activities.  It is a known human carcinogen.  Breathing radon can lead to lung cancer.  Drinking water containing radon may cause an increased risk of stomach cancer.  Presently EPA is reviewing a standard for radon in water.
Volatile Organic Contaminants	Units	MCLG	MCL	Level  Detected	Range	Year	Violation Yes/No	Typical Source of Contaminant
Total Trihalomethanes (TTHMs)	ppb	n /a	80	5.4	n/a	2006	NO	By-product of drinking water chlorination.
Volatile Organic Contaminants	Units	MRDLG	MRDL	Average Level  Detected	Range	Year	Violation Yes/No	Typical Source of Contaminant
Chlorine	ppm	4	4	0.41	0.0 - 0.5	2006	NO	Water additive used to control microbes
Inorganic Contaminants	Units	MCLG	AL	90th percentile sample value	# sites above AL	Date	Violation Yes/No	Typical Source of Contaminant
Copper	ppm	1.3	1.3	0.032	0 of 5	2006	NO	Corrosion of household plumbing system
Source Assessment Information
		Summary of Susceptibility Factors
Source Name	Date	Low	Med	High
Bedrock Well # 5	3/18/02	9	2	1
Bedrock Well # 6	3/18/02	9	2	1
The complete Assessment Report is available for inspection.  For more information call Gary Tetley or visit NH DES's Drinking Water Source Assessment Program web site at www.des.state.nh.us/dwspp