Guam Waterworks Authority Clean Water Act Settlement Information Sheet
(January 30, 2024) Guam Waterworks Authority (GWA) agreed to a consent decree with the United States to improve the quality of its sewer system, estimated to cost approximately $400 million, to address unauthorized overflows of untreated sewage and other violations of the Clean Water Act. The Government of Guam is also a party to the agreement.
- Overview
- Violations
- Injunctive Relief
- Pollutant Impacts
- Health Effects and Environmental Benefits
- Comment Period
- Contact
Overview of Company
Guam Waterworks Authority (GWA) owns and operates four Wastewater Treatment Plants (WWTPs) on Guam. GWA’s collection system consists of approximately 320 miles of gravity sewer and force mains, approximately 6,500 manholes, and 82 pump or ejector stations.
Violations
The United States alleges that GWA violated the Clean Water Act and terms and conditions of its National Pollutant Discharge Elimination System permits, which set limits for how much of a certain pollutant an entity is allowed to discharge into a waterbody. GWA’s alleged violations include effluent limit exceedances, failure to prevent sanitary sewer overflows (SSOs), and failure to properly operate and maintain its system.
Injunctive Relief
The proposed settlement includes specific requirements for GWA to upgrade its collection system to address SSOs to the Pacific Ocean. GWA will conduct a comprehensive assessment of its sanitary sewer system to identify defective sewer pipes and gravity mains in poor condition. The assessment results will be used to prioritize rehabilitation efforts aimed to prevent the occurrence of future SSOs. During the first three years of implementation of this settlement, GWA will focus its efforts on assessing and rehabilitating three critical pump stations. GWA will conduct a system-wide capacity assessment and address areas where SSOs have occurred or are predicted to occur, especially during large rain events. GWA will implement a capacity, management, operation, and maintenance program which includes comprehensive system cleaning and a grease control program to minimize SSOs caused by sewer blockages. The total cost of implementing these and other required measures is estimated to be approximately $400 million over the 10-year period to complete the injunctive relief.
GWA will also submit a plan to upgrade its Agaňa/Hagåtňa WWTP to secondary treatment, implementation of which will be required in a subsequent consent decree.
Pollutant Impacts
Through the implementation of the proposed Decree, the following estimated annual pollutant reductions will result:
- 716 pounds of total suspended solids;
- 685 pounds of biochemical oxygen demand; and
- 127 pounds of total nitrogen and total phosphorus.
Health Effects and Environmental Benefits
Total Suspended Solids (TSS) – TSS indicates the measure of suspended solids in wastewater, effluent or water bodies. High levels of TSS in a water body can diminish the amount of light that penetrates the water column and reduce photosynthesis and the production of oxygen.
Biological Oxygen Demand (BOD) – BOD is an indirect measure of the biologically degradable material present in organic wastes. High BOD means there is an abundance of biologically degradable material that will consume oxygen from the water during the degradation process. It may take away oxygen that is needed for aquatic organisms to survive.
Nutrients – Excess levels of nitrogen and phosphorus in waters can produce harmful algal blooms. These blooms contribute to the creation of hypoxia or “dead zones” in water bodies where dissolved oxygen levels are so low that most aquatic life cannot survive.
Comment Period
The proposed settlement, lodged in the U.S. District Court for the District of Guam, is subject to a minimum 30-day public comment period and final court approval. Information on submitting comment is available at the Department of Justice website.
Contact
For more information, contact:
Chrisna Baptista
Municipal Enforcement Branch
Water Enforcement Division
Office of Enforcement and Compliance Assurance
U.S. EPA
1200 Pennsylvania Ave., NW
Washington, DC 20460
Phone: (202) 564-4272
Chrisna Baptista (baptista.chrisna@epa.gov)