| DUXBURY WATER DEPARTMENT Groundwater | MA4082000 | 10 | 3 | |
| NATICK WATER DEPARTMENT Groundwater | MA3198000 | 6 | 3 | |
| SHARON WATER DEPT Groundwater | MA4266000 | 6 | 3 | |
| ACTON WATER SUPPLY DISTRICT Groundwater | MA2002000 | 8 | 2 | |
| ABINGTON/ROCKLAND JOINT WTR. WORKS Surface Water | MA4001000 | 8 | 2 | |
| HANOVER WATER DEPT, MA Groundwater | MA4122000 | 8 | 2 | |
| MARSHFIELD WATER DEPARTMENT Groundwater | MA4171000 | 8 | 2 | |
| MIDDLEBOROUGH WATER SUPPLY Groundwater | MA4182000 | 8 | 2 | |
| NORTH ATTLEBORO WATER DEPT Groundwater | MA4211000 | 8 | 2 | |
| AQUARION WATER COMPANY, MILLBURY Surface Water | MA2186000 | 7 | 2 | |
| ROWLEY WATER DEPARTMENT Groundwater | MA3254000 | 7 | 2 | |
| BRIDGEWATER WATER DEPARTMENT Groundwater | MA4042000 | 7 | 2 | |
| DARTMOUTH WATER DIVISION Groundwater | MA4072000 | 7 | 2 | |
| HOLBROOK PUBLIC WORKS DEPT Surface Water | MA4133000 | 7 | 2 | |
| NORWELL WATER DEPARTMENT Groundwater | MA4219000 | 7 | 2 | |
| MANCHESTER BY THE SEA DPW Surface Water | MA3166000 | 6 | 2 | |
| WELLESLEY WATER DIVISION Groundwater | MA3317000 | 6 | 2 | |
| WOBURN WATER DEPT. Groundwater | MA3347000 | 6 | 2 | |
| BARNSTABLE FIRE DISTRICT Groundwater | MA4020000 | 6 | 2 | |
| EASTON WATER DIV Groundwater | MA4088000 | 6 | 2 | |
| RANDOLPH WATER DEPARTMENT Surface Water | MA4244000 | 6 | 2 | |
| FRANKLIN WATER DEPARTMENT, MA Groundwater | MA2101000 | 5 | 2 | |
| GRAFTON WATER DISTRICT Groundwater | MA2110000 | 5 | 2 | |
| HOLLISTON WATER DEPARTMENT Groundwater | MA2136000 | 5 | 2 | |
| MAYNARD DPW, WATER DIVISION Groundwater | MA2174000 | 5 | 2 | |
| MEDFIELD WATER DEPT. Groundwater | MA2175000 | 5 | 2 | |
| MILFORD WATER COMPANY MX | MA2185000 | 5 | 2 | |
| MILLIS WATER DEPT Groundwater | MA2187000 | 5 | 2 | |
| NORFOLK WATER DIVISION Groundwater | MA2208000 | 5 | 2 | |
| SHREWSBURY WATER DEPARTMENT Groundwater | MA2271000 | 5 | 2 | |
| CHELMSFORD WATER DISTRICT Groundwater | MA3056000 | 5 | 2 | |
| HAMILTON WATER DEPT Groundwater | MA3119000 | 5 | 2 | |
| TOPSFIELD WATER DEPARTMENT Groundwater | MA3298000 | 5 | 2 | |
| WENHAM WATER DEPT. Groundwater | MA3320000 | 5 | 2 | |
| WESTFORD WATER DEPARTMENT GU | MA3330000 | 5 | 2 | |
| ATTLEBORO WATER DEPT Surface Water | MA4016000 | 5 | 2 | |
| BRAINTREE WATER AND SEWER DEPT. Surface Water | MA4040000 | 5 | 2 | |
| COHASSET WATER DEPT Surface Water | MA4065000 | 5 | 2 | |
| FOXBORO WATER DEPARTMENT Groundwater | MA4099000 | 5 | 2 | |
| STOUGHTON WATER DEPARTMENT Groundwater | MA4285000 | 5 | 2 | |
| WRENTHAM WATER DIVISION Groundwater | MA4350000 | 5 | 2 | |
| WARE WATER DEPT Groundwater | MA1309000 | 4 | 2 | |
| AUBURN WATER DISTRICT, MA Groundwater | MA2017000 | 4 | 2 | |
| HOPEDALE WATER DEPARTMENT Surface Water | MA2138000 | 4 | 2 | |
| DEDHAM WESTWOOD WATER DIST. Groundwater | MA3073000 | 4 | 2 | |
| DIGHTON WATER DISTRICT Surface Water | MA4076000 | 4 | 2 | |
| MANSFIELD WATER DIVISION Groundwater | MA4167000 | 4 | 2 | |
| PLAINVILLE WATER DEPARTMENT GU | MA4238000 | 4 | 2 | |
| SCITUATE WATER DIVISION Groundwater | MA4264000 | 4 | 2 | |
| BELLINGHAM DPW WATER SEWER DIV. Groundwater | MA2025000 | 3 | 2 | |
| WESTBOROUGH WATER DEPARTMENT Groundwater | MA2328000 | 3 | 2 | |
| LINCOLN WATER DEPT Surface Water | MA3157000 | 3 | 2 | |
| PEPPERELL DPW WATER DIVISION Groundwater | MA2232000 | 2 | 2 | |
| NEEDHAM WATER DEPT Groundwater | MA3199000 | 2 | 2 | |
| TOWN OF AVON Groundwater | MA4018000 | 2 | 2 | |
| NORTON WATER DEPARTMENT Groundwater | MA4218000 | 7 | 1 | |
| RAYNHAM CENTER WATER DISTRICT Groundwater | MA4245000 | 7 | 1 | |
| IPSWICH DPU WATER DEPT Groundwater | MA3144000 | 6 | 1 | |
| SUDBURY WATER DISTRICT Groundwater | MA3288000 | 6 | 1 | |
| WAYLAND WATER DEPARTMENT Groundwater | MA3315000 | 6 | 1 | |
| SWANSEA WATER DISTRICT GU | MA4292000 | 6 | 1 | |
| HOLDEN WATER DIVISION, DPW Surface Water | MA2134000 | 5 | 1 | |
| HOPKINTON WATER DEPARTMENT Groundwater | MA2139000 | 5 | 1 | |
| SHIRLEY WATER DISTRICT Groundwater | MA2270000 | 5 | 1 | |
| BILLERICA WATER WORKS Surface Water | MA3031000 | 5 | 1 | |
| LYNN WATER AND SEWER COMM Surface Water | MA3163000 | 5 | 1 | |
| LYNNFIELD CENTER WATER DISTRICT Groundwater | MA3164000 | 5 | 1 | |
| MIDDLETON WATER DEPT. Surface Water | MA3184000 | 5 | 1 | |
| PEABODY WATER DEPT. Surface Water | MA3229000 | 5 | 1 | |
| HAYSTACK ESTATES Groundwater | MA3330019 | 5 | 1 | |
| CENTERVILLE OSTERVILLE MARSTONS MILLS WD Groundwater | MA4020002 | 5 | 1 | |
| WEIR RIVER WATER SYSTEM Surface Water | MA4131000 | 5 | 1 | |
| WEST BRIDGEWATER WATER DEPT Groundwater | MA4322000 | 5 | 1 | |
| MEDWAY WATER DEPARTMENT Groundwater | MA2177000 | 4 | 1 | |
| TEMPLETON MUNIC. LIGHT AND WATER PLANT Groundwater | MA2294000 | 4 | 1 | |
| CONCORD WATER DEPT, MA Groundwater | MA3067000 | 4 | 1 | |
| KENWOOD WATER DISTRICT Surface Water | MA3079001 | 4 | 1 | |
| GROVELAND WATER DEPARTMENT Groundwater | MA3116000 | 4 | 1 | |
| CANTON WATER DEPT Groundwater | MA4050000 | 4 | 1 | |
| HALIFAX WATER DEPARTMENT Groundwater | MA4118000 | 4 | 1 | |
| FITCHBURG DPW, DIV. OF WATER SUPPLY Surface Water | MA2097000 | 3 | 1 | |
| LUNENBURG WATER DISTRICT Groundwater | MA2162000 | 3 | 1 | |
| TOWNSEND WATER DEPARTMENT Groundwater | MA2299000 | 3 | 1 | |
| UXBRIDGE DPW, WATER DIVISION Groundwater | MA2304000 | 3 | 1 | |
| WEBSTER WATER DEPARTMENT Groundwater | MA2316000 | 3 | 1 | |
| WEST BOYLSTON WATER DISTRICT Surface Water | MA2321000 | 3 | 1 | |
| CAMBRIDGE WATER DEPARTMENT Surface Water | MA3049000 | 3 | 1 | |
| DRACUT WATER SUPPLY DISTRICT Groundwater | MA3079000 | 3 | 1 | |
| LOWELL REGIONAL WATER UTILITY Surface Water | MA3160000 | 3 | 1 | |
| SALISBURY WATER DEPARTMENT Groundwater | MA3259000 | 3 | 1 | |
| TEWKSBURY WATER DEPARTMENT Surface Water | MA3295000 | 3 | 1 | |
| TYNGSBOROUGH WATER DISTRICT Surface Water | MA3301000 | 3 | 1 | |
| WAKEFIELD WATER DEPT Surface Water | MA3305000 | 3 | 1 | |
| BOURNE WATER DISTRICT Groundwater | MA4036000 | 3 | 1 | |
| East Bridgewater Water Dept. Groundwater | MA4083000 | 3 | 1 | |
| BOYLSTON WATER DISTRICT Groundwater | MA2039000 | 2 | 1 | ⚠ High Risk |
| NEWBURYPORT WATER DEPARTMENT MX | MA3206000 | 2 | 1 | |
| HANSON WATER DEPARTMENT Groundwater | MA4123000 | 2 | 1 | |
| NORTH ADAMS WATER DEPT Surface Water | MA1209000 | 1 | 1 | |
| BLACKSTONE WATER DEPARTMENT Groundwater | MA2032000 | 1 | 1 | ⚠ High Risk |
| LEOMINSTER WATER DIVISION Groundwater | MA2153000 | 1 | 1 | |
| STERLING WATER DEPARTMENT Groundwater | MA2282000 | 1 | 1 | |
| DANVERS WATER DEPT. Groundwater | MA3071000 | 1 | 1 | |
| MERRIMAC WATER DEPARTMENT Groundwater | MA3180000 | 1 | 1 | |
| SEEKONK WATER DISTRICT Groundwater | MA4265000 | 1 | 1 | |
| ONSET FIRE DISTRICT Groundwater | MA4310003 | 1 | 1 | |
| WALPOLE WATER DEPT Groundwater | MA4307000 | 6 | 0 | |
| HATFIELD WATER DEPT Surface Water | MA1127000 | 5 | 0 | |
| WHITMAN WATER SYSTEM Surface Water | MA4338000 | 5 | 0 | |
| YARMOUTH WATER DEPARTMENT Groundwater | MA4351000 | 5 | 0 | |
| AYER DPW WATER DIVISION Groundwater | MA2019000 | 3 | 0 | |
| CHERRY VALLEY/ ROCHDALE WATER DISTRICT Surface Water | MA2151001 | 3 | 0 | |
| PAXTON WATER DEPARTMENT Surface Water | MA2228000 | 3 | 0 | |
| METHUEN WATER DEPT Surface Water | MA3181000 | 3 | 0 | |
| NORTH READING WATER DEPT. Surface Water | MA3213000 | 3 | 0 | |
| HYANNIS WATER SYSTEM, TOWN OF BARNSTABLE Groundwater | MA4020004 | 3 | 0 | |
| DEVENS MASSDEVELOPMENT Groundwater | MA2019001 | 2 | 0 | |
| BEVERLY WATER DEPT Surface Water | MA3030000 | 2 | 0 | |
| LAWRENCE WATER WORKS Surface Water | MA3149000 | 2 | 0 | |
| SALEM WATER DEPARTMENT, MA Surface Water | MA3258000 | 2 | 0 | |
| WILMINGTON WATER DEPT GU | MA3342000 | 2 | 0 | |
| NORTH SAGAMORE WATER DISTRICT Groundwater | MA4036002 | 2 | 0 | |
| DENNIS WATER DISTRICT Groundwater | MA4075000 | 2 | 0 | |
| OAK BLUFFS WATER DISTRICT Groundwater | MA4221000 | 2 | 0 | |
| PEMBROKE WATER DIVISION DPW Groundwater | MA4231000 | 2 | 0 | |
| PLYMOUTH WATER DEPARTMENT, MA Groundwater | MA4239000 | 2 | 0 | |
| HOLYOKE WATER WORKS Surface Water | MA1137000 | 1 | 0 | |
| ORANGE WATER DEPT Surface Water | MA1223000 | 1 | 0 | |
| PITTSFIELD DPU WATER DEPT Surface Water | MA1236000 | 1 | 0 | |
| WESTFIELD WATER DEPT Groundwater | MA1329000 | 1 | 0 | |
| WHATELY WATER DEPARTMENT Groundwater | MA1337010 | 1 | 0 | |
| GROTON WATER DEPARTMENT Groundwater | MA2115000 | 1 | 0 | |
| HUDSON WATER SUPPLY Groundwater | MA2141000 | 1 | 0 | |
| AQUARION WATER COMPANY OXFORD Groundwater | MA2226000 | 1 | 0 | |
| MCI SHIRLEY Groundwater | MA2270001 | 1 | 0 | |
| SOUTHBRIDGE WATER DEPARTMENT Surface Water | MA2278000 | 1 | 0 | |
| WORCESTER DPWP, WATER SUPPLY DIVISION Surface Water | MA2348000 | 1 | 0 | |
| ANDOVER WATER DEPT Surface Water | MA3009000 | 1 | 0 | |
| Ashland Water & Sewer Dept. Groundwater | MA3014000 | 1 | 0 | |
| BURLINGTON WATER DEPT Surface Water | MA3048000 | 1 | 0 | |
| NORTH CHELMSFORD WATER DIST Groundwater | MA3056002 | 1 | 0 | |
| REVERE WATER DIVISION (MWRA) Surface Water | MA3248000 | 1 | 0 | |
| WEST NEWBURY WATER DEPARTMENT MX | MA3324000 | 1 | 0 | |
| MASHPEE WATER DISTRICT Groundwater | MA4172039 | 1 | 0 | |
| CITY OF NEW BEDFORD DPI Surface Water | MA4201000 | 1 | 0 | |
| PINEHILLS WATER COMPANY, INC. Groundwater | MA4239055 | 1 | 0 | |
| NORTH RAYNHAM WATER DISTRICT Groundwater | MA4245002 | 1 | 0 | |
| WEYMOUTH WATER DEPARTMENT Groundwater | MA4336000 | 1 | 0 | |