Northern Mariana Islands tap water quality

35 community water systems serving 63,904 people.

Data: U.S. EPA · How we read the data · How we check it

systems with PFAS above a federal limit

48,524

people served by them

systems EPA tested for PFAS

systems above the lead action level

PFAS: EPA's 2023–2025 testing. Lead: results from the last five years.

Water systems with PFAS above the federal limit

Based on EPA's UCMR 5 results (2023–2025) compared to the April 2024 limits, the way EPA compares them. Systems have until 2029 to comply. Largest first.

Commonwealth Utilities Corp (Saipan)
48,524 people · Groundwater · Northern Mariana Islands
PFOS above limitAlso: Coliform bacteria violations · PFHxS detected · Lithium above screening level

Northern Mariana Islands PFAS report: chart, rankings and data to download →

Largest water systems in Northern Mariana Islands

Commonwealth Utilities Corp (Saipan)
48,524 people · Groundwater · Northern Mariana Islands
PFOS above limitAlso: Coliform bacteria violations · PFHxS detected · Lithium above screening level
Saipan Ice And Water
3,101 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sample
Commonwealth Utilities Corp (Tinian)
3,005 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 2 health-based violations since 2016
Commonwealth Utilities Corp (Rota)
2,504 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 2 health-based violations since 2016
Star Water
1,522 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sample
Kensington Hotel Water System
634 people · Groundwater · Northern Mariana Islands
Lead above action level
Pacific Islands Club Water System
554 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sample
Finasisu Terrace Apartment Water System
393 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sample
The Water Company
310 people · Purchased groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016
Marianas Ice And Water
300 people · Purchased groundwater · Northern Mariana Islands
Not in EPA's PFAS sample
Tinian Ice And Water
300 people · Purchased groundwater · Northern Mariana Islands
Not in EPA's PFAS sample
Kensington Dormitory Water System
260 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sample
Anaks Condominium Water System
243 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sample
Rota Crystal Water System
226 people · Purchased groundwater · Northern Mariana Islands
Not in EPA's PFAS sample
3K Ice And Water Company
208 people · Purchased groundwater · Northern Mariana Islands
Not in EPA's PFAS sample

Most health-based violations since 2016

Commonwealth Utilities Corp (Saipan)
48,524 people · Groundwater · Northern Mariana Islands
PFOS above limitAlso: Coliform bacteria violations · PFHxS detected · Lithium above screening level
Pacific Palms Water System
56 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 6 health-based violations since 2016
Aqua Water
170 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 4 health-based violations since 2016
Afetna Supermarket Water System
40 people · Purchased groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 4 health-based violations since 2016
Crystal Ice And Water
30 people · Purchased groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 4 health-based violations since 2016
Diamond Water Gualo Rai
55 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 3 health-based violations since 2016
Modern Stationary Water System
60 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 3 health-based violations since 2016
Commonwealth Utilities Corp (Rota)
2,504 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 2 health-based violations since 2016
Commonwealth Utilities Corp (Tinian)
3,005 people · Groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 2 health-based violations since 2016
Saipan Vegas Water System
100 people · Groundwater · Northern Mariana Islands
Lead near 2027 levelAlso: 2 health-based violations since 2016
The Water Company
310 people · Purchased groundwater · Northern Mariana Islands
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016
Tropical Drinking Water
47 people · Groundwater · Northern Mariana Islands
Coliform bacteria violation

All Northern Mariana Islands utilities on this site

Every Northern Mariana Islands system serving 50,000+ people or with PFAS above a federal limit, A to Z. Download all 35 systems as CSV.

Commonwealth Utilities Corp (Saipan)

Questions

Does Northern Mariana Islands tap water have PFAS?

EPA tested 1 community water system in Northern Mariana Islands for 29 PFAS between 2023 and 2025. 1 had at least one regulated PFAS detected, and 1 had an entry-point average above a 2024 federal limit. Those 1 systems serve about 48,524 people (76% of people on community water in Northern Mariana Islands). Systems have until 2029 to meet the limits.

How many Northern Mariana Islands water systems have violations?

12 systems in Northern Mariana Islands had at least one health-based violation since 2016 (46 violations in total). 10 violations are currently listed as unaddressed.

Which Northern Mariana Islands water systems are over the lead action level?

2 systems had a lead 90th percentile above the 15 ppb action level in their most recent results from the last five years. Lead depends on each home's pipes, so a test of your own tap is the only way to know your level.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.