DEQ warns DPW vs. drainage project

Division of Environmental Quality Ignacio V. Cabrera has warned the Department of Public Works against pushing through with the Chalan Monsignor Guerrero Phase III Drainage Improvement Project without complying with the requirement to install a stormwater treatment system.

In a letter to DPW Secretary Juan B. Cepeda, the DEQ Chief said the department will be in violation of its Earthmoving Permit unless the required system is built.

However, DEQ will be willing to work out a compliance schedule with DPW to postpone any formal enforcement proceedings while the public works office tries to convince the CNMI leadership of the importance of providing additional funding for the project.

Mr. Cabrera explained that the stormwater treatment system will prevent further degradation of water quality in Saipan lagoon.
DEQ data shows that there has been a gradual decline in water quality lagoon-wide over the past 10 years, particularly in beach areas adjacent to major storm drains.

Since data near the project site indicates that the water quality in this area is still good, DEQ is still concerned with the impact the new drainage may cause.

Mr. Cabrera noted that the present design of the project will drain a large area that was inundated during rainstorms, with very little runoff reaching the lagoon, if any. This will increase the overall volume of stormwater delivered to the lagoon.

However, increasing the area drained also increases the pollutants being discharged such as oil and grease, toxic residue from vehicle brake pads, and fecal coliform bacteria. Again, this will result in more beach closures during rainy season.

Pollution of this type from many different sources is called “non-point source” (NPS) pollution and is the subject of many local and federal regulations and programs. Researches have been done and efforts are underway to develop methods of treating stormwater to prevent NPS pollution.

Designs and measures that are developed as a result of this research are referred to as “Best Management Practices” (BMPs). Mr. Cabrera said the design approach that DEQ has proposed is currently accepted as one of the more effective BMPs.

The U.S. Environmental Protection Agency now regulates small municipal storm drainage systems such as the DPW project under the National Pollutant Discharge Elimination System, Phase II rules. These regulations require the implementation of BMPs at storm drains to reduce water quality problems.

“Although the CNMI has some time to come into compliance with this rule, we are hoping to take care of this now, under the CNMI’s own Earthmoving and Erosion Control Program, to avoid extensive involvement with the U.S. EPA in the future,” the DEQ chief said.

Mr. Cabrera offered the agency’s assistance in convincing the CNMI leadership of the importance of installing a stormwater treatment system. After all, the eventual resolution of the situation may set a precedent on how the CNMI will deal with the issue of degrading water quality and beach closures in the future.