Public water system record
Emerald Lake
Serves an area of Hillsborough County, NH · 1,300 people served
Federal records show 5 health-based violations and 6 monitoring/reporting issues for Emerald Lake in the last ten years, including an unresolved Groundwater Rule violation.
System profile
- Health-based violations, last 10 years
- 5
- Resolved
- 4
- Unresolved
- 1
- Any acute record
- No
- Monitoring issues, last 10 years
- 6
Key facts
- Emerald Lake draws water from 7 wells.
- Highest measured level in the last 10 years: Arsenic, 0.023 mg/L, federal limit 0.01 mg/L (2.3 times the limit), 2019.
- Record on file since 1995, with 26 health-based violations before October 19, 2016.
Check whether Emerald Lake serves your address
Health-based violations
Since October 2016Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.
| Contaminant | Rule family | Start date | Status | Acute |
|---|---|---|---|---|
|
Groundwater Rule
Treatment technique failure
|
140 | Oct 2, 2020 | Active | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.013 mg/L, federal limit 0.01 mg/L (1.3 times the limit)
|
330 | Jan 1, 2020 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.023 mg/L, federal limit 0.01 mg/L (2.3 times the limit)
|
330 | Oct 1, 2019 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.023 mg/L, federal limit 0.01 mg/L (2.3 times the limit)
|
330 | Jul 1, 2019 | Resolved | No |
|
Arsenic
Contaminant limit exceeded
Measured 0.015 mg/L, federal limit 0.01 mg/L (1.5 times the limit)
|
330 | Apr 1, 2019 | Resolved | No |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Haloacetic Acids (HAA5)
Monitoring and reporting
|
Jul 1, 2024 | Resolved |
|
Total Trihalomethanes (TTHMs)
Monitoring and reporting
|
Jul 1, 2024 | Resolved |
|
Revised Total Coliform Rule
RPT
|
Nov 10, 2021 | Resolved |
|
Revised Total Coliform Rule
Monitoring violation
|
Oct 1, 2021 | Resolved |
|
Public Notice
OTHER
|
Jan 23, 2020 | Resolved |
|
Public Notice
OTHER
|
Jan 27, 2002 | Active |
Full record since 1995
EPA's records for Emerald Lake go back to 1995. Before October 19, 2016 they list 26 health-based violations (26 resolved) and 14 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1990s | 0 | 1 |
| 2000s | 17 | 7 |
| 2010 to October 18, 2016 | 9 | 6 |
| October 19, 2016 to 2019 | 3 | 0 |
| 2020s | 2 | 5 |
Most recent health-based violation before October 19, 2016: Total Coliform (acute), began July 2013, Resolved.
Show all 26 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Total Coliform (acute)
Contaminant limit exceeded
|
Jul 1, 2013 | Resolved |
|
Groundwater Rule
Treatment technique failure
|
Apr 24, 2013 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Sep 1, 2012 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Jul 1, 2012 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Nov 1, 2011 | Resolved |
|
Fluoride
Contaminant limit exceeded
Measured 4.1 mg/L, federal limit 4 mg/L (at or just above the limit)
|
Oct 1, 2011 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Sep 1, 2011 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Aug 1, 2011 | Resolved |
|
Fluoride
Contaminant limit exceeded
Measured 4.5 mg/L, federal limit 4 mg/L (1.1 times the limit)
|
Jul 1, 2011 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Jul 1, 2006 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Apr 1, 2006 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Jan 1, 2006 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Oct 1, 2005 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Jul 1, 2005 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Apr 1, 2005 | Resolved |
|
Fluoride
Contaminant limit exceeded
|
Jan 1, 2005 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Jan 1, 2005 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Oct 1, 2004 | Resolved |
|
Fluoride
Contaminant limit exceeded
|
Oct 1, 2004 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Jul 1, 2004 | Resolved |
|
Fluoride
Contaminant limit exceeded
|
Jul 1, 2004 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Apr 1, 2004 | Resolved |
|
Fluoride
Contaminant limit exceeded
|
Apr 1, 2004 | Resolved |
|
Arsenic
Contaminant limit exceeded
|
Jan 1, 2004 | Resolved |
|
Fluoride
Contaminant limit exceeded
|
Apr 1, 2003 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Dec 1, 2001 | Resolved |
What the violations mean
Arsenic
4 incidentsArsenic exceeded the federal limit
Long-term arsenic exposure is linked to cancer and cardiovascular effects
Groundwater Rule
1 incidentThe system did not complete a treatment step or action that the Groundwater Rule requires (a treatment technique violation).
The utility had to notify customers about this violation.
Where the water comes from
Emerald Lake draws water from 7 wells.
Annual water quality report
Emerald Lake must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.
Where the state allows it, systems serving fewer than 10,000 people may publish the report in a local newspaper or news site instead of mailing it, and must provide a copy on request.
Find a posted report with EPA's Consumer Confidence Report search
Testing your own water
To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by New Hampshire.
Certified drinking water labs by state EPA guidance for private wells