Long Term Care & Monitoring
How long will the temporary debris storage (TDS) area site be allowed?
It is likely the TDS will be in operation for 1-2 years, one to transfer Lahaina ash/debris to the TDS, and another year for all ash/debris and cover soil to be transferred safely to a permanent disposal site.
Will the TDS site be cleaned up once the ash and debris are removed and transported to the permanent disposal site?
Yes. The entire area around the TDS site will be restored and sampled to confirm that the operations had any impact on the land. If any impact is found, it will be cleaned up to the condition in which it was found prior to construction.
Will the permanent disposal site meet the requirements of federal or state landfill regulations?
Yes. While the permanent disposal site design has not yet been finalized, it will feature an engineered liner, environmental monitoring, and other controls to protect long-term community and environmental health, wherever it is located.
How will the permanent disposal site be built to be protective of human health, wildlife, agricultural lands, marine life, and the environment?
The permanent disposal site will be built to stringent design standards intended to completely encapsulate the ash and debris between heavy plastic and clay composite liners (base and final cover) specifically designed for this purpose. Debris (plastic, dust) will be contained within the site and prevented from blowing onto adjacent lands or the ocean. In addition, regular supervision and maintenance to remove leachate to mitigate any potential leaking of contaminants, will be performed. Finally, groundwater monitoring wells will be installed around the permanent disposal site to detect any changes to groundwater conditions.
How will the permanent disposal site be monitored over the long term to ensure they protect human health and the environment? By whom?
A long-term monitoring and maintenance plan will be developed by Maui County in coordination with Hawai’i DOH. It will involve the final cover and stormwater drainage/diversion structures, monitoring for methane gas, air quality monitoring (while in operation), removal of any leachate (liquid from the ash/debris), monitoring for leakage, and perimeter groundwater monitoring. Together with methane gas and groundwater monitoring, these systems will monitor potential impacts to the environment.
Who will maintain and monitor the TDS and permanent disposal site during construction, operation and closure? Will monitoring information be made available on-line for the public to view?
The County of Maui will maintain and monitor both the Central Maui Landfill and permanent disposal site to ensure compliance with best construction practices and environmental compliance.The County of Maui passed an ordinance (#5596, or Bill 120, 1/21/2024) requiring environmental monitoring and safety measures at the TDS site, which US ACE and County of Maui Environmental Management are working to ensure compliance with. Information and data relating to air quality, water quality, and overall progress will be provided at https://www.mauirecovers.org/debriscontainment.
How long will the permanent disposal site last?
These type of disposal units are designed to last in perpetuity when maintained and monitored, which is planned to be conducted by Maui County.
Will leachate continue to be collected?
Yes. Any leachate that accumulates on the uppermost liner at a depth of greater than 30 cm will be removed using pumps and proper treatment/disposal at a wastewater treatment plant if necessary until it is no longer being generated.
How does groundwater monitoring work? Can it be cleaned up if it becomes contaminated?
Monitoring wells are installed down at the groundwater level and beyond. Samples are taken using special pumps either quarterly or semi-annually for a complete list of heavy metals (including arsenic, cobalt and lead) and volatile organic compounds (VOCs) following very specific guidance provided in state regulations, for a period of 30 years. This period can be extended if warranted.
If these compounds are detected, the groundwater monitoring goes into assessment monitoring, which increases the frequency and list to be sampled. In some cases, additional wells are installed so that the extent of groundwater contamination can be understood. If the contamination is found to be a threat to drinking water, systems (i.e., pump & treat, bioremediation) can be used to clean up the groundwater or at least stop it from spreading.
How long will the HDPE liners and PVC leachate collection pipes last? Will the liners rip or tear as waste is being placed into the TDS or permanent disposal site?
After installation, it is standard practice to protect the HDPE liner with a geotextile (a thick fabric) and 2-3’ thick layer of sand, soil or gravel on top prior to waste placement to prevent any waste items from piercing or ripping the liner during placement. When properly maintained and protected, the plastic liner and leachate collection components of engineered landfills can last a very long time, as they have been demonstrated to be resistant to subsurface conditions and are considered state of the art in landfill construction. Regardless, the permanent disposal site will continue to be monitored by Maui County for as long as possible along with the other closed landfills on the island.
Will groundwater monitoring data be available to the public?
Yes. A summary of groundwater data will be produced after each monitoring event (every few months) and posted on this website.
What can be done if groundwater should become contaminated in the future?
Groundwater remediation technologies and processes (i.e., bioremediation, pump and treat) are widely available in the environmental cleanup industry. Construction and implementation, in the unlikely event it is needed, are part of the post-closure care requirements for the permanent disposal site.
Will there be monitoring of water quality along the shoreline and the Olowalu Reef Complex?
Officials are currently discussing the need and feasibility of water quality monitoring options along the shoreline near Olowalu with the Hawai’i Department of Land and Natural Resources, Division of Aquatic Resources. There are existing monitoring efforts by Hawai’i DOH nearby, which focus primarily on water quality for safe aquatic recreation. Both the TDS and permanent disposal area are effectively going to quarantine the waste between impermeable liners which will be extensively monitored for leakage. These controls will prevent any ash/debris from making it into the watershed and the ocean.
Will Lahaina, the temporary debris storage area, or permanent disposal site be considered ‘Superfund’ sites?
No. Though USEPA used resources (personnel, equipment, contractors, etc.) from its Superfund program with funding through a mission assignment from FEMA to conduct Phase 1 cleanup operations, this isn't considered a Superfund site. A Superfund site is typically a cleanup project where no other regulatory authority can conduct the work and is meant to address former industrial activities. The permanent disposal site will be built and operated under state and Federal laws other than the Superfund law.