Oahu residents are being urged to reduce water use

The Honolulu Board of Water Supply on Thursday asked all Oahu water users to voluntarily reduce usage by 10% — a result of the loss of a key city water source after the Navy’s water was contaminated by fuel from its Red Hill fuel storage facility.

“We need to reduce aggregate demand on the island to protect our groundwater resources from depletion,” BWS manager and chief engineer Ernest Lau said in a press release. “This is necessary to ensure that Oahu‘s drinking water supply remains healthy and sustainable over the long term. When we closed our Halawa shaft due to the Navy’s Red Hill Crisis, we knew asking for voluntary conservation was an opportunity. We had hoped to avoid this. Unfortunately, we find ourselves in a difficult situation that is not of our own making.”

At a news conference Thursday, Lau and BWS officials specifically urged the 400,000 residents of Metro Honolulu and the 20,000 residents of Aiea, as well as area businesses, schools, hospitals and government agencies to immediately reduce their water use.

Lau said the reason was the supply outage due to the closure of the city’s Halawa Well, which normally provides 20% of the drinking water for the Honolulu metropolitan area from Aiea in the west to Hawaii Kai and the Kalama Valley in the east.

“Right now, this situation is due to the Red Hill crisis,” Lau said. “If the Halawa shaft were online, we wouldn’t have to (ask that).”

The situation was exacerbated by low rainfall in February, which was just 51% of normal, he said. Looking ahead to summer, which is typically Hawaii’s driest season, demand could exceed supply.

Additionally, there is a risk that over-pumping to meet demand could affect water quality, Lau said, adding, “The most important thing we monitor very closely is the salinity of the water.”

Additional pumping has already doubled the salt or chloride levels in the artesian wells at the Beretania Street BWS station in the past two weeks, said Kevin Ihu, program administrator in the Water Systems Management Division. The Beretania station “is one of our biggest sources,” he said.

Pumping at the Beretania station had to be reduced immediately to avoid contaminating the aquifer “by pulling too much salt into the freshwater,” Lau said, adding that only Beretania had seen a chloride spike “so far.”

The Pentagon announced Monday that the Department of Defense would permanently shut down and defuel the Navy’s massive fuel tank facility, which leaked oil into the Navy’s drinking water system for about 93,000 people.

“We know that the aquifer under the fuel tanks and near the fuel system is contaminated with fuel,” Lau said.

“We don’t know how it’s moving with the groundwater, but we suspect there’s movement in the Halawa Valley,” he said, which is why the three wells were closed to prevent possible contamination of all of Oahu’s groundwater.

Five other city wells near the Navy shaft are tested weekly and no fuel contamination was found, he added.

While Lau expressed the board’s reluctance to ask the public to voluntarily reduce water use, he did not rule out the possibility of mandatory action if it were needed.

“If everyone reduces their consumption by 10% now, we might not have to resort to increasingly restrictive mandatory conservation later in the year,” he said, noting that the only time it had happened in his 40 years at BWS was late at night 1980s was when mandatory restrictions during a severe drought resulted in a 20% drop in water use.

During the winter, BWS water sources typically produce about 130 million gallons per day. In the summer, that number jumps to about 150 million gallons per day with demand — an increase largely attributed to irrigation and “non-essential outdoor uses,” said Barry Usagawa, BWS program administrator in the Department of Water Resources.

The State Department of Land and Natural Resources announced Tuesday that the US drought monitor shows all of Hawaii’s main islands will experience at least moderate drought this winter.

January had average rainfall, and while December rainfall was 276% of normal, much of that rain ran off without replenishing the aquifer, Lau said.

Even if Oahu gets some rain now, it won’t be enough to replenish the aquifer now without reducing demand.

Otherwise, Lau said, there could be localized areas of water supply disruptions in the summer, including lower water pressure, particularly in higher-elevation areas, and water shortages.

Among the top water users BWS works with are government agencies like the Department of Education, said Kathleen Elliott-Pahinui, BWS chief information officer.

“If we each save a little water, together we save a lot,” Lau said.

“We need everyone’s kokua,” he added.

PRESERVATION TIPS

Recognizing that March 22 is World Water Day, which focuses on groundwater this year, the Board of Water Supply urges Oahu customers to be mindful of their water consumption in their daily activities by adopting practices, avoid wasting water.

The department proposes the following measures, such as those published online in BWS’ “Seven simple ways to save water” at boardofwatersupply.com/7ways.

Tips include:

>> Irrigate lawns and gardens before 9am or after 5pm

>> Shorter showers.

>> Do not leave the tap running while washing dishes or brushing your teeth.

Other educational and informational resources on the agency’s website include signing up for heavy use alerts and leak detection.

Discounts are also available to residential and commercial customers who purchase rain collection barrels and certain devices that carry the US Environmental Protection Agency’s Energy Star and Water Sense labels.