Water Quality

The tables below summarize the finish water quality from the Town's water treatment plants.  Iron should be less than 0.3 mg/l, manganese less than 0.05 mg/l, color less than 15 color units.  Turbidity is a measure of the cloudiness of the water:

Pond Street Water Treatment Plant

Month and YearpHIron (mg/l)Manganese (mg/l)Color (units)Turbidity (NTU)Free Chorine (mg/l)Total Chlorine (mg/l)Finished Water Gallons
01-20177.760.0130.0291.20.06

1.04

1.2627,409,299
02-20177.850.0110.03210.071.021.1921,875,548
03-20177.800.0120.0330.90.060.931.1225,574,548
04-20177.770.0120.0330.90.070.971.1428,492,120
05-20177.800.0100.0441.70.070.921.0726,831,650
06-20177.790.0110.0532.40.080.891.0630,010,867
07-20177.840.0110.0603.40.090.941.1830,126,389
08-20177.740.0130.0422.60.091.031.2730,579,503
09-20177.740.0130.0411.30.081.041.2923,940,561
10-20177.800.0150.0411.40.081.121.3523,540,561
11-20177.770.0120.0442.60.081.151.3918,384,853
12-20177.710.0110.0371.10.071.131.2918,384,853
01-20187.680.0110.0380.90.071.051.2519,433,696
02-20187.760.0120.0330.80.061.051.2617,688,112
03-20187.880.0120.0300.80.071.141.3624,119,628
04-20187.740.0100.0251.10.071.051.3325,514,482
05-2018

7.75

0.0100.0322.10.071.121.3930,861,841
06-20187.720.0120.0402.20.081.181.4132,411,164
07-20187.740.0130.0372.10.081.181.4733,864,240
08-20187.770.0150.0311.90.101.151.4830,960,464
09-20187.850.0160.03920.091.181.5127,366,894
10-20187.890.0190.03930.121.151.4822,912,342
11-20187.890.0220.03620.081.381.7219,902,443
12-2018

7.70

0.0210.03110.081.421.7617,775,398
01-20197.610.0180.02810.131.201.4818,874,875
02-20197.700.0190.02700.081.301.5514,707,697
03-20197.670.0230.02700.071.241.4817,683,065
04-20197.690.0210.03210.091.201.3922,014,787
05-20197.690.0200.03420.081.081.2722,788,313
06-20197.630.0160.03820.081.211.4218,879,406
07-20197.640.0170.05350.111.241.5223,765,055
08-20197.580.0150.05550.141.271.5824,338,947
09-20197.500.0140.03940.121.271.5621,883,259

Beal Water Treatment Plant

Month and YearpHIron (mg/l)Manganese (mg/l)Color (units)Turbidity (NTU)Free Chlorine (mg/l)Total Chlorine (mg/l)Finished Water Gallons
01-20177.660.0330.0130.80.090.840.974,741,778
02-20177.680.0280.01710.091.011.135,819,262
03-20177.680.0250.0140.20.080.891.068,117,179
04-20177.690.0210.0171.10.080.941.097,277,961
05-20177.690.0230.0190.30.070.971.107,987,268
06-20177.700.0180.0160.40.080.921.058,498,247
07-20177.660.0240.0160.20.090.891.038,714,340
08-20177.640.0190.0150.10.090.840.957,694,384
09-20177.630.0220.0190.50.080.860.967,295,911
10-20177.660.0190.0250.30.070.961.097,213,934
11-20177.680.0250.0120.40.070.991.167,527,572
12-2017

7.71

0.0290.0130.20.070.941.107,906,017
01-2018

7.71

0.0220.0140.10.081.011.187,726,863
02-20187.670.0220.0140.30.080.991.167,513,908
03-20187.670.0230.01100.081.021.202,952,012
04-2018DIDNOTRUNDid not runDid not runDid not runDid not runDid not run
05-20187.610.0440.0250.20.110.841.402,917,588
06-20187.600.0360.0190.20.100.841.239,746,810
07-20187.610.0270.0230.50.100.841.2610,775,193
08-20187.570.0270.0220.50.100.841.259,096,104
09-20187.580.0240.02300.100.841.356,218,653
10-20187.590.0280.02110.090.841.438,513,241
11-20187.580.0360.02110.090.841.657,622,144
12-20187.630.0360.02210.090.841.458,349,099
01-20197.610.0360.02310.111.161.387,788,428
02-20197.640.0380.01600.091.101.329,138,174
03-20197.680.0300.01510.091.201.398,369,419
04-20197.660.0330.02100.091.201.437,861,069
05-20197.670.0400.02310.091.231.445,335,020
06-20197.630.0430.01710.091.251.436.073,416
07-20197.690.0490.03410.111.101.278,995,857
08-20197.640.0360.02310.131.231.389,648,609
09-20197.680.0320.02410.111.311.478,361,730

Broadway Water Treatment Plant

Month and YearpHIron (mg/l)Manganese (mg/l)Color (Units)Turbidity (NTU)Free Chlorine (mg/l)Total Chlorine (mg/l)Finished Water Gallons
01-20177.750.0250.01300.080.961.025,100,170
02-20177.850.0250.0161.00.100.850.975,810,353
03-20177.880.0210.0301.10.11

0.75

0.924,342,840
04-20178.060.0130.0310.40.120.991.101,356,950
05-20177.790.0170.0260.50.091.011.1510,050,148
06-20177.770.0200.0170.80.100.931.089,389,497
07-20177.750.0260.0300.80.090.921.0710,986,511
08-20177.840.0260.0170.10.090.931.0714,650,549
09-20177.810.0280.0140.40.090.881.0212,243,694
10-20177.640.0220.0150.30.080.941.107,794,088
11-20177.710.0190.0180.60.080.931.157,124,984
12-20177.690.0270.0140.30.080.931.109,721,707
01-20187.730.0260.0130.40.080.901.0910,959,586
02-20187.680.0230.0140.30.090.961.168,665,393
03-20187.660.0250.0160.10.080.901.0910,250,119
04-20187.650.0220.0120.30.070.991.1312,716,259
05-20187.730.0250.012020.081.181.3712,010,194
06-20187.760.0220.0220.30.081.141.3311,847,544
07-20187.700.0200.0170.30.091.141.359,832,427
08-20187.710.0280.0130.30.091.121.329,740,407
09-20187.750.0170.01400.081.111.319,118,909
10-20187.790.0280.01510.091.151.346,830,890
11-20187.830.0260.02010.081.381.597,029,026
12-20187.780.0250.02210.091.301.517,775,874
01-20197.570.0300.02210.081.051.267,848,213
02-20197.510.0280.02010.091.121.366,577,928
03-20197.560.0290.01700.081.041.247,365,654
04-20197.580.0290.02100.081.091.226,868,279
05-20197.590.0300.02000.081.221.3312,355,378
06-20197.610.0240.02210.091.201.386,073,416
07-20197.540.0200.03710.091.081.1910,490,174
08-20197.550.0210.03720.101.091.2410,264,819
09-20197.630.0180.02010.091.251.394,899,361

The DPW's Open Data page contains downloadable files of the raw and finished water test results from the three treatment plants as well as production summaries from the plants.

Disinfection Byproducts

The Town chlorinates all of its drinking water to kill harmful bacteria that is present in the untreated water.  State and Federal regulations require the Town to maintain a residual amount of chlorine, called free chlorine, in the treated water that leaves the treatment plant.  This chlorine guards against harmful bacteria that may enter the distribution system. Unfortunately, this residual chlorine reacts over time with trace amounts of residual organic matter that is also in the water to form disinfection byproducts.  These byproducts are regulated as excessive amounts ingested over a lifetime of exposure may cause health problems in some individuals.  We are currently in violation of Federal standards for total trihalomethanes (TTHM's) at one site in North Hanover.   To reduce the amount of disinfection byproducts, the Town is in the process of altering the water treatment processes at all three treatment plants.  These changes are expected to come on-line sometime in early 2020.  To minimize the byproducts now, the Town performs periodic flushing as well as minimizes the use of the Pond Street #3 well which is the raw water source that contributes the most organic material to the Town's water.  Most of the organics are removed by the existing treatment processes, but trace amounts of organic material do pass through the treatment processes.  The organic material in and of itself is not harmful, but when combined with chlorine result in the formation of Total Trihalomethanes.  Unfortunately, heavy periodic demand, especially during the summer months, requires the use of the Pond Street #3 well.

Brown Water - Iron and Manganese

Residents may occasionally experience discolored water coming out of their tap.  Iron and manganese are commonly found in groundwater in Massachusetts.  While the Town's treatment plants do an excellent job removing the minerals, 1-2 percent of the iron and manganese typically pass through the plants.  Both minerals will react with chlorine to form oxides of the minerals and will typically settle out in the water distribution system.  During periods of higher flow such as a water break, during a fire, or when the summer consumption increases and flows increase in the pipes, the sediments can be lifted off of the bottom of the pipes and will discolor the water.  This discoloration is generally an aesthetic problem, causing staining on laundry and on plumbing fixtures.  To control the sediments and reduce the likelihood of problems, the Town flushes water mains in the spring and in the fall.   

Some scientific studies have shown that manganese in high concentrations can have health effects.  The normal concentration of manganese in Hanover's water is typically 1/10th of the health advisory level.  The primary source of manganese intake in humans is from regular foods and as such manganese intake from the water is insignificant for most people.  However, infants often receive the bulk of their manganese nutrition through baby formula, not solid food.  As such, the EPA has issued a health advisory for excessive water based manganese when high levels of manganese in water it is used to make baby formula. 

The Massachusetts Department of Environmental Protection has developed an excellent fact sheet on manganese in drinking water which summarizes the information provided in the EPA health advisory in simple terms. 

The Town urges residents to use common sense with respect to discolored water.  We recommend that residents run their faucets which will generally clear up the discolored water.  If the discoloration persists, please call the DPW office and we will investigate the source of the problem and weather permitting, will attempt to mitigate the issue.  We urge residents who may have concerns regarding manganese to read the MassDEP fact sheet and the EPA health advisory and to discuss their concerns with their health care provider.

Consumer Confidence

DPW is proactive and transparent in its quest to provide the highest quality of water possible. Please click on the following link for a narrative of the steps and tests that are performed to ensure the quality of the water over the past few years:

Home Water Treatment Resources

While the Town reduces contaminants in the source water to levels well below state and federal standards, some people have asked how can they make their water better. Home treatment devices can polish the water, reducing the occasional impact of sediments and some other contaminants.  The Town will not recommend any one device over another, but in general simple cartridge style filters will take care of most problems as long as they are changed on a regular basis.  When being changed, residents can expect to see discoloration of the filter cartridges as the filters are designed to trap sediments in the filter.  We urge residents who are considering home filtration to due their research and speak with multiple vendors to choose the best filter for your needs.  The following links are helpful in evaluating home treatment devices.

Useful Water Quality Links