Waimanalo Gulch Landfill upgrades completed

The U.S. Environmental Protection Agency (EPA) and Hawaii Department of Health (DOH) have announced the city and county of Honolulu and WM of Hawaii Inc. (WMH) have completed required upgrades to maintain compliance with stormwater regulations at the Waimanalo Gulch Sanitary Landfill in Kapolei, Oahu.

The city and county, which own the landfill, and WMH, which operates the facility, took on these upgrades under a 2019 consent decree they entered into with EPA, the U.S. Department of Justice and DOH.

“By completing critical upgrades at Oahu’s largest landfill, Waimanalo Gulch, WM and the city and county of Honolulu have taken necessary steps to protect Oahu’s environment and public health from harmful stormwater discharges,” EPA Pacific Southwest Regional Administrator Martha Guzman says. “Addressing pollution in stormwater is a vital part of the Clean Water Act. Enforcement action such as the now completed consent decree helps protect the cherished groundwater, surface water, and beaches of Oahu.”

In 2009, WMH and the county and city of Honolulu began work on a landfill expansion and new stormwater diversion structure. During construction, Waste Management used temporary stormwater pipes to divert stormwater around the landfill. Those pipes were breached in 2010 and 2011, resulting in discharges of waste to the Pacific Ocean. EPA and DOH entered into a consent decree in 2019 with both the owner and operator to address ongoing compliance issues at the landfill.

CCH and WMH completed a series of facility upgrades pursuant to the consent decree to maintain compliance with stormwater regulations, including retrofitting the landfill’s existing stormwater drainage pipeline, installing a trash screen, revising and upgrading their stormwater pollution control plan, complying with specific operational and monitoring limits to control pollution from the stormwater basin and obtaining an indiv­­­idual stormwater permit for the facility.

The city and county of Honolulu and WMH paid a combined penalty of $425,000, which was split evenly between the U.S. and the state of Hawaii. The state has used the funds for coral reef and habitat restoration, monitoring and conservation on the leeward coast of Oahu.

The U.S. District Court of Hawaii terminated the consent decree after the EPA concluded that its requirements were met.

The Aug. 31 termination of the consent decree marks the end of a long-term effort by EPA and the state of Hawaii to bring the landfill—the largest on Oahu—into compliance with laws designed to protect public health, natural ecosystems and wildlife.