Is Loudon, NH Tap Water Safe to Drink?
Graded F — but Lead was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
28/100
waterverge.com Loudon, NH — Water Quality Report
Loudon's drinking water received a grade of F (28 out of 100), indicating failing water quality. The city's 7 water systems serve approximately 948 residents using groundwater.
Lead levels were measured at 31.0 ppb (90th percentile), which exceeds the EPA action level of 15 ppb. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 374 violations on record, including 58 health-based violations. 92 remain unresolved.
What to know about Loudon's water
Loudon ranks #116 out of 119 cities in New Hampshire for water quality, placing it among the lowest-rated in the state.
Loudon relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
Lead levels exceed the EPA action level of 15 ppb, which typically indicates aging lead service lines or lead solder in the distribution system. An NSF 53-certified filter is strongly recommended for drinking and cooking water.
As a small community water system, Loudon may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 61 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Loudon, NH water safe to drink?
Loudon's drinking water has significant quality concerns based on EPA testing data. With a grade of F (28/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 7 water systems serve approximately 948 residents using groundwater (wells).
Recent water quality updates for Loudon
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Loudon's water quality assessment. Grade: F (28/100).
Contaminants: Arsenic.
Contaminants: Revised Total Coliform Rule.
1 health-based. Contaminants: Arsenic.
Federal disaster declaration (FEMA DR-3360). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4026). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Loudon's water supply.
Exceeds EPA action level. Lead service line replacement and point-of-use filtration recommended.
Violation history
Loudon's water system has 374 total violations on record, including 58 health-based violations. 92 remain unresolved. 61 violations were issued in the last 5 years.
Flood & environmental risk
Merrimack County has experienced 9 federally declared disasters since 1973. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Suncook River.
Where does Loudon's water come from?
Loudon's drinking water comes from groundwater (wells), supplied by 7 water systems serving approximately 948 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Suncook River (river).
What Loudon residents can do
Recommended: NSF 53-certified pitcher or under-sink filter. This addresses the specific contaminants found in Loudon's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Loudon's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Loudon
Industrial polluters nearby
Reported releases to surface water by facilities near Loudon, ranked by pounds discharged annually.
Total reported releases to surface water: 257 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
MERRIMACK STATION BOW, NH03304 | Ammonia | 254 | 10.0 mi |
ELEKTRISOLA INC. BOSCAWEN, NH03303 | Copper | 2 | 8.7 mi |
HEAT & CONTROL PEMBROKE, NH03275 | — | — | 6.5 mi |
KALWALL CORP FLAT SHEE T DIV BOW, NH03304 | — | — | 9.3 mi |
LINDE ADVANCED MATERIAL TECHNOLOGIES INC. CONCORD, NH03301 | — | — | 4.9 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Drought conditions
D2 — severe droughtMerrimack County is currently in D2 (severe drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Merrimack County has experienced 9 federally declared disasters since 1973. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Loudon's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 31.0 | 15 | ppb | Inorganic | Over Limit |
Lead level (90th percentile)
Latest reading: 31.0 ppb (2009)
EPA action level: 15 ppb
See how Loudon compares by contaminant
Explore where Loudon ranks among all New Hampshire cities for specific contaminants.
Water source & infrastructure
Where Loudon's water comes from
Loudon's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by private ownership and serves approximately 948 people through 7 water systems.
Water bodies near Loudon
Loudon is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Loudon
| System Name | PWSID | Population | Source |
|---|---|---|---|
| FREEDOM HILL/PINE RIDGE EST | NH1403030 | 370 | GW |
| VILLAGES AT LOUDON | NH1402020 | 250 | GW |
| KOS MANUFACTURED HOUSING CMNTY | NH1403010 | 137 | GW |
| PRESIDENTIAL PINES/UPPER | NH1403020 | 60 | GW |
| PRESIDENTIAL PINES/LOWER | NH1403040 | 51 | GW |
| VOA/NNE SENIOR HOUSING | NH1402030 | 50 | GW |
| FLINTLOCK APTS | NH1402010 | 30 | GW |
How Loudon compares
Full New Hampshire rankings →Loudon's score of 28/100 is below the average of 69/100 among major New Hampshire cities. 10 of 10 nearby cities score higher.
Nearby cities
View New Hampshire rankings →About Loudon, NH
Wikipedia →Loudon is a town in Merrimack County, New Hampshire, United States. The population was 5,576 at the 2020 census. Loudon is the home of New Hampshire Motor Speedway.
Learn more about your water
Guides and resources related to Loudon's water quality findings.
Explore water quality across Merrimack
Frequently asked questions
Is Loudon, NH tap water safe to drink?
Loudon's water quality earned a grade of F (28/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #116 out of 119 cities tested in New Hampshire.
What contaminants are in Loudon's water?
Lead was measured at 31.0 ppb (90th percentile). 374 violations are on record.
How is Loudon's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Loudon?
Yes — lead levels exceed the EPA action level of 15 ppb. We recommend an NSF 53-certified filter or reverse osmosis system. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Loudon's water come from?
Loudon's water is sourced from Groundwater. The city has 7 water systems serving approximately 948 residents.
What health violations has Loudon's water system had?
Loudon has 58 health-based violations on record. The most recent violation was recorded in January 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 92 violations remain unresolved.
Is Loudon's groundwater at risk of contamination?
Loudon uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 374 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Loudon's water compare to other cities?
Loudon ranks #116 out of 119 cities in New Hampshire (better than 3% of state cities) and #15726 out of 15744 cities nationally (0th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.