Marine Water Monitoring

Marine water samples are collected weekly by WQS/NPS staff and tested by DEQ's Environmental Surveillance Laboratory to monitor the chemical, physical, and microbial quality of our near shore waters that surround our most popular and frequented beaches. This includes the islands of Saipan, Tinian, Rota, and Managaha.  The microbial fecal indicator bacteria, Enterococci, is used to assess the presence of human or animal waste. Enterococci levels that exceed the CNMI Water Quality Standards may indicate that there is a health risk associated with recreating in marine waters at these sites. These sites are then "red flagged" in a Public Beach Advisory.

Collecting water samples on Rota's reef flat


Filtering nutrient samples for transport to DEQ Laboratory


Preparing samples for microbial testing using the 24 Hr Enterolert Method


Fluorescence indicates the Presence of Enterococci


Additional water samples are taken upon reef flats surrounding these islands and in Saipan's lagoon by WQS/NPS and DCRM's Marine Monitoring Team (MMT). The MMT also conducts biological assessments of the reef and benthic habitat at these sites. This biological data combined with Water Quality Data, and other studies conducted by federal and local partners, are used to make a comprehensive assessment of the health of CNMI marine waters. Findings are provided to US EPA, Congress, and the general public in the biennial CNMI 305(b) and 303(d) Water Quality Assessment Integrated Report. All waters bodies assessed as not attaining their designated uses ("fishable and swimmable") are put on the US EPA 303(d) list of impaired waters. Impaired waters are then required to have a Total Maximum Daily Load (TMDL) set in order for natural resource managers to work towards their restoration. The TMDL identifies the maximum amount of a pollutant that a body of water can receive while still meeting water quality standards. The impaired water bodies of Saipan have a TMDL set for bacteriological contamination, as of December 2017. Each of these impaired water bodies also have a "Report Card" for providing policy makers and managers direction in restoration efforts.