Derry Water Dept, NH
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2015-2017). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Derry Water Dept at a glance
Derry Water Dept serves about 17,528 people through 4,365 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Rockingham County, New Hampshire. EPA system ID: NH0611010. Ask the utility on your bill for your address in their service line inventory.
Lead results over time
Against the period ending 2017 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Derry Water Dept is 0 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2017 | 0 (not detected) |
| 2017 | 0 (not detected) |
| 2016 | 0 (not detected) |
Against other New Hampshire systems
Of the 124 New Hampshire systems with a lead result, the median latest reading is 16 ppb; 62 are over 15 ppb right now and 64 have gone over at some point. Derry Water Dept's reported as 0 (not detected) sits at the 19th percentile in New Hampshire and the 38th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Nearby utilities
185 other systems share Rockingham County; 17 of them have a higher latest lead result than Derry Water Dept. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Portsmouth Water Works | 33,000 | 0 (not detected) |
| Salem Water Dept | 21,080 | 2 ppb |
| Seabrook Water Dept | 14,000 | 3 ppb |
| Exeter Water Dept | 12,236 | 0 (not detected) |
| Pease Trade Port | 9,900 | 0 (not detected) |
| Hampstead Area Water | 7,153 | 2 ppb |
| Londonderry | 6,255 | 4 ppb |
| Newmarket Water Works | 5,030 | 2 ppb |
| Rye Water Dist | 4,300 | 0 (not detected) |
| Raymond Water Dept | 3,300 | 1 ppb |
What to do in your house
Look up your address in Derry Water Dept's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Derry Water Dept whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. Why sampled homes are the worst-case ones is in the guide to reading the number. A zero today does not rule out a jump later - the rules are tightening in 2027.