LETTER: Kahului Wastewater Site’s Proposed Seawall a Hazard

Editor’s note: This letter has also been submitted to the state Board of Land and Natural Resources, which will reconvene Friday, May 9.

By Tom Cannon, Haiku

The Kahului Wastewater Reclamation Facility. Courtesy photo.

Dear Board Members:

As a lifelong Maui resident and professional architect and land planner, I request that you deny the Conservation District Use Application (CDUA: MA-3688) for a proposed new seawall makai of the Kahului Wastewater Reclamation Facility (KWRF) on the grounds that the proposal would:
1. increase hazards to endangered and other native Hawaiian species in the sea and at Kanaha Wildlife Sanctuary (just across the street from KWRF),
2. increase hazards to the KWRF sewage treatment plant itself,
3. increase hazards to the health and wellbeing of Maui’s citizens (especially those in nearby Kahului town),
4. adversely affect nearby beaches by increasing sand erosion, and
5. allow for continuation of the ill-conceived injection of treated sewage into the ground a few feet from the shoreline when a reasonable viable alternative is currently available.

Flooding in Kahului resulting from the 2011 Japan tsunami. Photo courtesy oceanjournal-sylvablogspot.com.

In addition to these reasons that directly relate to the Conservation District Rules and associated Hawaii Revised Statutes, the proposed action also would waste upwards of $4.5 million of Maui taxpayer money.

The KWRF sewage plant sits on the shore at the very front of a tsunami flood zone. Whereas the top of the proposed seawall would be 13 feet above sea level, this specific location on Maui was hit by a tsunami in 1946 estimated to have been 28 feet high, as shown in Figure 1 from the Pacific Tsunami Museum.

Figure 1: Scientists have said that it is the debris that causes most of the destruction from a tsunami, not just the water alone. With the proposed addition of a seawall constructed of numerous multi-ton stones held together by gravity alone, the debris hazard from a tsunami larger than 13 feet is increased greatly, as shown in Figure 2.

The proposed seawall is designed to repel normal waves up to 13 feet high hitting from the front, but tsunamis are not just one wave pushing from the front. They are a series of multiple waves pushing and pulling. Serious tsunami waves arrive with tremendous force from the front, destroying many things in their path, then suck the debris of their destruction back out into the sea, only to be hurled back inland with the following waves in the tsunami series.

Figure 2: Project EIS Section drawing of proposed seawall with height of 1946 Maui tsunami shown.

The existing KWRF/Project site includes not just vats of raw sewage to be battered by the proposed seawall’s heavy stones and flooded by a tsunami the size of the 1946 wave, putting raw sewage into Kanaha Pond. The site also has a building situated closest of all the buildings to the sea and parallel to the shore with about 10 tons of liquid chlorine stored in it. If a stone from the proposed seawall (or other heavy debris from a tsunami) were to crash through the plate glass windows in the Chlorine Building and crack one of the tanks, the liquid chlorine would become lethal chlorine gas (used as a weapon in World War 1). Chlorine gas is heavier than air and stays down near ground level where human beings are. Trade winds would carry the deadly gas downwind into densely populated Kahului town, where it would destroy the lungs of anyone breathing it.

Figure 3: Chlorine Building a few feet from the shore.

For many years, Maui County has strongly discouraged seawalls. As Mayor Arakawa is quoted saying in an Oct. 24, 2013 Lahaina News article “(i)n the community plan and in the general rules, what we’ve said is we don’t want to harden the coastline because of the erosion factor; it creates an abnormal batter that effects the coastline.” UH Professor Chip Flecher teaches that “(s)eawalls are constructed where there is erosion, but they do not solve the erosion, they simply protect the land without protecting the beach.” Thus, the proposed seawall fronting KWRF would cause a loss of nearby beaches, in addition to increasing the potential for environmental catastrophe and human disaster.

Figure 4: Close up (taken the day after the 2011 tsunami) showing chlorine tanks, break-away glass windows, & (if you look closely) the tsunami water height.

The EIS for the proposed seawall says that relocating the sewage treatment plant would cost upwards of $450-million, which seawall proponents have said Maui County can’t afford. However, the county administration is in possession of at least one proposal to relocate the plant inland near the existing dump (where the type 1 wastewater could be gravity-fed to nearby agriculture) at a cost of merely $150-million. As you can see in the attached relocation proposal outline [The attachment has not been included here -Ed.], the company has shown the county how this cost would affect the ratepayer minimally, has offered to finance the cost of the relocation, and would run the new plant or train others to run it (at the county’s discretion).

Environmental Management Deputy Michael Miyamoto asked in a recent Maui News article if we would rather pump sewage inland or reclaimed water. In that the pumping cost for either is about the same, I would ask the deputy, which has the greater potential for irrevocable environmental damage, a sewage plant on the coast in a tsunami zone that injects treated (type 2) water into the ground, or a pipe moving sewage away from the coastline, where it can be turned into more usable type 1 water without the chemical dangers of chlorine. Water from a plant near the dump could be gravity fed into HC&S irrigation flumes in trade for the existing more potable surface water from East Maui to treat for human consumption.

The intent of having volunteer members on the BLNR is to represent the interests of community residents, just as with Maui’s 25-member General Plan Advisory Committee (GPAC) that I chaired for its three years of volunteer work. GPAC voted that Maui have a policy of moving the KWRF out of the tsunami zone as soon as possible for very good reasons. Unfortunately, the county administration ignored that advice. I now ask, on behalf of GPAC and all Maui residents, that you deny the proposal associated with CDUA: MA-3688 so that we can begin an orderly relocation of KWRF while this is still possible. Further delaying this common-sense move will unnecessarily cost Maui’s citizens millions of dollars, while extending the time we are in danger of losing what we cannot afford to lose — our lives, our environment, and our economic wellbeing. Thank you very much.

Malama pono.

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