| A B C Water Conditioning Co | 413-283-9363 | 57 Commercial | Thorndike | MA | 01079 |
| Amherst Water Laboratory | 413-549-0009 | 180 Pine St | Amherst | MA | 01002 |
| Aqua Technology Inc | 413-569-1200 | 13 Industrial Rd | Southwick | MA | 01077 |
| Aqua-Matic Hidden Dog Fence Sy | 413-567-3458 | 258 Brookwood Dr | Longmeadow | MA | 01106 |
| Bay State Lawn Sprinkl Inc | 413-782-7778 | 307 Gillette Ave | Springfield | MA | 01118 |
| Berkshire Enviro-Labs | 413-243-1416 | 260 Main St | Lee | MA | 01238 |
| Clean Streams Inc | 413-732-4186 | 231 Western Ave | West Springfield | MA | 01089 |
| Connecticut Valley Artesian Well Co Inc | 413-525-7656 | 58 Bond St | East Longmeadow | MA | 01028 |
| Connecticut Walley Artesian Well Co Inc | 413-267-4236 | Mc Bride Rd | Monson | MA | 01057 |
| Culligan Water Conditioning Of The Pioneer Val | 413-599-0200 | 2376a Boston Rd | Wilbraham | MA | 01095 |
| Diamond Water Systems Inc | 413-536-8186 | 530 Main St | Holyoke | MA | 01040 |
| Ducharme Co Inc Swimg | 413-584-4214 | 95 Spring St | Leeds | MA | 01053 |
| Environmental Testing Lab Inc | 413-592-2500 | 170 Montgomery St | Chicopee | MA | 01020 |
| Gilcil | 413-532-6089 | 85 Sargeant St | Holyoke | MA | 01040 |
| Green Grass Irrigation Co | 413-783-2553 | 73 Audley Rd | Springfield | MA | 01118 |
| Howard Laboratories Inc | 413-549-8260 | 750 N Pleasant St | Amherst | MA | 01002 |
| Krofta Engineering Corp | 413-637-0740 | 101 Yokun Ave | Lenox | MA | 01240 |
| Lenox Institute Of Water Te | 413-637-3025 | 101 Yokun Ave | Lenox | MA | 01240 |
| Mack Mechanical Plumbing & Heating | 413-267-0066 | 289 Main St | Monson | MA | 01057 |
| Pratt C E & Sons | 413-569-5571 | 237 Sheep Pasture Rd | Southwick | MA | 01077 |
| Quabbin Analytical Laboratory Inc | 413-323-7134 | Stadler | Belchertown | MA | 01007 |
| Riordon Associates | 413-586-1060 | 176 Brookside Cir | Florence | MA | 01060 |
| Shaklee Bestwater Products | 413-527-7524 | 116 East St | Easthampton | MA | 01027 |
| South Deerfield Water Supply District | 413-665-3540 | Sugar Loaf | South Deerfield | MA | 01373 |
| Taplin F C Company | 413-781-5097 | 120 Interstate Dr | West Springfield | MA | 01089 |
| Water Analysis Laboratory | 413-746-4352 | 1252 Elm St | West Springfield | MA | 01089 |
| Water Supply Citizens Advisory Committee | 413-586-8861 | 138 Russell St | Hadley | MA | 01035 |
| Waterwright Co | 413-367-2379 | 323 Federal St | Montague | MA | 01351 |
