Hawaii First Water

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

(Apr 2017) New research from the University of Hawaiʻi at Mānoa reveals a large part of the the heavily urbanized area of Honolulu and Waikīkī is at risk of groundwater inundation—flooding that occurs as groundwater is lifted above the ground surface due to sea level rise. Shellie Habel, lead author of the study and doctoral student in the Department of Geology and Geophysics, School of Ocean and Earth Science and Technology (SOEST), and colleagues developed a computer model that combines ground elevation, groundwater location, monitoring data, estimates of tidal influence and numerical groundwater-flow modeling to simulate future flood scenarios in the urban core as sea level rises three feet, as is projected for this century under certain climate change scenarios.

“This flooding will threaten $5 billion of taxable real estate; flood nearly 30 miles of roadway; and impact pedestrians, commercial and recreation activities, tourism, transportation and infrastructure,” said Habel. “The flooding will occur regardless of seawall construction, and thus will require innovative planning and intensive engineering efforts to accommodate standing water in the streets.”

Current problems with inundation

construction trench in Waikiki

This construction trench in Waikīkī shows that the water table is nearly at the ground surface at high tide. (credit: UH Mānoa Coastal Geology Group)

Simulations of groundwater inundation chart

Simulations of groundwater inundation (blue) and narrow unsaturated space (yellow) today and considering sea level rise of approximately 1, 2 and 3 ft during an average spring (monthly maximum) tide stage. (credit: UH Mānoa Coastal Geology Group)

Surprisingly, the team of researchers also discovered 86 percent of active cesspools in the study area are likely currently inundated by groundwater. This suggests that cesspool effluent is now entering coastal groundwater and coastal environments in the study area. Sea level rise of approximately three feet would fully inundate 39 cesspools, introducing effluent at the ground surface where people work and live. This presents a serious health concern that will become progressively more serious as contaminated waters begin breaching the ground surface.

They also found that the water table is close to the ground surface—within two feet at high tide—in many places. This narrow unsaturated space means that groundwater inundation will become a serious concern well before the end of the century. When it rains and infiltration fills this space, it is a problem already.

“Waikīkī, the gateway of the state’s tourism industry, currently has such narrow unsaturated space that many construction projects working below the ground surface have to dewater the excavation before construction can begin,” said Habel.

Adaptation to future sea level rise

“Our findings suggest that coastal communities in Hawaiʻi and globally are exposed to complex groundwater flooding hazards associated with sea level rise in addition to the typical concerns of coastal erosion and wave overtopping,” said Chip Fletcher, professor of geology and geophysics, associate dean of SOEST and principal investigator on the study. “Groundwater inundation will require entirely unique adaptation methods if we are to continue to live in and develop the coastal zone. Coastal planners and community stakeholders will need to work with architects, engineers, geologists, ecologists, economists, hydrologists and other innovative thinkers in order to manage these problems.”

This study identified particular locations and infrastructure that will be vulnerable to future flooding and is a crucial first step towards addressing future challenges. The team of researchers hope to use this methodology to identify future flooding and at risk infrastructure in other locations, as well as assist in developing adaptation efforts among vulnerable coastal communities.

This work was funded by Hawaiʻi Department of Land and Natural Resources, the Honolulu Board of Water Supply, UH Sea Grant and and HKL Castle Foundation.

City crews respond to another massive leak at Ko Olina resort

January 2017, KO OLINA, OAHU (HawaiiNewsNow) –

City crews on Tuesday responded to a massive sewage spill at the Ko Olina resort in West Oahu, the second such spill in the area in the last three months.

The rupture occurred within 32 feet of another leak, one that happened back in November, where more than 200,000 gallons of untreated wastewater flooded into an undeveloped area on the Diamond Head side of the resort.

“We have a massive sewage spill where a force-main broke,” said environmental activist Carroll Cox. “We were told about 8:15 this morning, the city called out all of its vacuum trucks, sent out an alert for all of them to report to this facility.”

Cell phone video, taken about an hour before city crews shut down the pipeline, shows thousands of gallons of raw sewage draining onto an area near a nearby golf course.

City crews dispatched nearly a dozen vacuum trucks, tankers and cesspool trucks to clean up the spill. The trucks later dumped the sewage into sewer lines away from the break, allowing it to be sent to a nearby treatment plant.

The spill was contained by about 10:30 a.m., and the cause is still under investigation.

City Environmental Services Director Lori Kahikina said it’s still too early to provide an estimate on the size of the spill, but said it could be as large as the last one. The previous leak was caused by corrosion.

“As of now, we know it’s a very large spill, similar to the last one,” she said. Kahikina says none of the sewage made its way to the ocean.

In the meantime, environmentalists are questioning whether the existing sewer lines can handle all of the development and growth at Ko Olina, including plans for a Atlantis resort in the area.

“There’s been some big development happening there, so it really questions whether all this growth can be accommodated for,” said Jodi Malinowski, Oahu Group Coordinator for Sierra Club Hawaii. “We’re disappointed that there’s been another spill.”

The city plans says it plans to begin repairs today. Over the longer term, it wants talk to developers to see if even larger sewage lines are needed, though repairs of that magnitude could potentiall cost taxpayers millions of dollars.

Copyright 2016 Hawaii News Now. All rights reserved.

Oahu’s Ala Wai Watershed Student Design Challenge

December: (Editor Kobayashi Note:  In case you missed it, the UH announced this competition for students at the Conservation Congress to deal with the continuing problems of the strategic Ala Wai Canal In Honolulu.  Here is the timetable for 2017, use the link to the challenge website and good luck!!)

The Ala Wai Watershed Student Design Challenge, was announced by the University of Hawai‘i at the U.S.-hosted 2016 IUCN World Conservation Congress. The Challenge looks to unlock student innovation and creativity to craft solutions that address critical urban watershed and island issues, specifically, restoring watershed ecologies and exploring culture’s contribution to sustainable development.

The University of Hawai’i seek ideas from the brightest minds of our youth and students to help advance the collective goals and action agenda of the Ala Wai Watershed Partnership (AWWP) (e.g., stream and ecosystem restoration, green stormwater infrastructure, water capture and reuse, sediment control, flood mitigation, contemporary urban ahupua’a, Ala Wai as a destination, education and engagement with community/youth, coalition of teams with local participation, etc.)

Here is a link to the challenge website…

TIMELINE
Sept 5th, 2016 – Design competition announced @ IUCN-WCC
Sept – Dec 2016 – Outreach to students
Jan 9th, 2017 – Design Challenge opens
Jan 9th-31st, 2017 – Registration period
March 17th, 2017  – Design entries close
May 2017 – Exhibition of design entries at various locations
Week of June 25th, 2017 – Winners announced at World Youth Congress 2017

UH researchers link quality of coastal groundwater with reef

December;

(Honolulu, HI) Land-use practices on tropical oceanic islands can have large impacts on reef ecosystems, even in the absence of rivers and streams. Land-based pollutants, such as fertilizers and chemicals in wastewater, infiltrate into the groundwaters beneath land and eventually exit into nearshore ecosystems as submarine groundwater discharge (SGD)—seeping into the coastal zone beneath the ocean’s surface. In a study published recently in PLOS ONE, University of Hawai‘i at Mānoa (UHM) scientists used a combination of field experiments and chemical analysis of water and algae to show that the quality of coastal groundwater plays a major role in determining the health of nearshore ecosystems in Hawai‘i.

Various sources of pollution, such as agriculture or sewage treatment facilities, have identifiable chemical signatures, particularly the isotopes of nitrogen in the nutrients they contain. This study assessed groundwater quality, coastal water quality, and reef health across six different bays on Maui with various potential sources of pollution. By comparing the nitrogen isotope signature of algae tissues and potential pollution, the research group traced nutrients in the algae back to their land-based sources.

This study is the first to show the extent of the impact of wastewater injection wells at Kahului Wastewater Reclamation Facility, Maui’s highest-volume sewage treatment plant, on Kahului Bay. In addition to relatively high nutrient levels in marine surface waters in Kahului Bay, shallow areas were almost entirely dominated by a thick fleshy mat of colonial zoanthids, a phenomenon not reported anywhere else in the state. A concurrent companion study to this work, led by James Bishop at the UHM Department of Geology and Geophysics, found that water collected from beach sands, which represents coastal groundwater, next to the Kahului Wastewater Reclamation Facility contained up to 75 percent treated wastewater—highlighting the impact of wastewater in this area.

For the rest of this article including citations see

 

Study finds injection wells, agriculture harming Maui bays

November 2016;

HONOLULU (AP) – A team of University of Hawaii scientists has completed a study of nearshore ecosystems across Maui that shows the harmful impacts of discharged treated wastewater.

The findings were published in the scientific journal PLOS ONE earlier this month.

The scientists analyzed water and algae at six locations around Maui, including Kahului Bay, which is adjacent to Maui’s highest-volume sewage treatment plant. A study of the bay found high nutrient levels in marine surface waters near the Kahului Wastewater Reclamation Facility and a “thick, fleshy mat” of colonial zoanthids, a coral-like organism.

For the rest of the article see this…

‘Ike Wai: Securing Hawai’i’s Water Future, supported by NSF EPSCoR

October (Editor Comment:  Although NSF granted the UH $20 Million for water research earlier this year, see link to see how the UH is beginning to formulate its water research plan and its video.  See the link here)

Hawai‘i depends exclusively on local water. The ‘Ike Wai project will provide data and models that address the grand challenge of water sustainability. A diverse workforce of data scientists and water researchers will work in concert with the community, government and business to inform decision makers with high-quality data and predictive capacity.  The project incorporates indigenous and local communities, and its robust, inclusive and diverse human capital pipeline of undergraduates, graduate students, postdocs and junior faculty will address water challenges at the academic and policy level.

Paddling championship goes forward at Keehi Lagoon, despite water quality concerns

August 2016, KEEHI LAGOON, OAHU (HawaiiNewsNow) –

(Editor Kobayashi Comment:  Stormwater pollution continues to be a problem on the islands which will not go away.  Fortunately the control of stormwater resources will continue to offer solutions to future freshwater scarcity problems on the islands.  If stormwater can be slowed and saved, both pollution and freshwater supply scarcity problems can be reduced.)

The Hawaiian Canoe Racing Association’s state championships are going forward this weekend at Keehi Lagoon, but at least five canoe clubs have decided not to participate because of ongoing water quality concerns.

Flooding from Tropical Storm Darby sent large debris and trash into Keehi Lagoon, putting an upcoming outrigger canoe championship in limbo.

Participants, meanwhile, are being told to stay in their canoe on race day and out of the water.

A Brown Water Advisory for Keehi Lagoon has been lifted, but health officials say bacteria levels in the lagoon remain high.

Despite the problems, association officials are trying to remain upbeat.

“The flags are up. People are out here practicing. The tents the food booths everything is getting set,” said Water Vierra, president of the Hawaiian Canoe Racing Association.

He added, “We’re encouraging all clubs to forgo the use of boat holders. They have the most exposure to the water.”

The problems at the lagoon started with Tropical Storm Darby, which sent debris and dirty run-off into the waterway popular among paddlers.

While much of the big debris has been cleared from the lagoon, bacteria levels at Keehi Lagoon are still high.

As of Friday afternoon, five Oahu canoe clubs have pulled out the race. They are: Outrigger Canoe Club, Hui Nalu O Hawaii Canoe Club, Lanikai Canoe Club, Na Keiki O Ka Mo’i Canoe Club and Manu O Ke Kai Canoe Club.

Still, Vierra said, some 3,000 paddlers are expected to come out for the competition. Typically, about 3,500 participate.

Paddlers practicing Friday used duct tape to cover open cuts on their arms and legs. And everyone was wearing slippers in and out of the water.

See the rest of the article here…

Researchers reveal cost-effective path to drought resiliency

July 2016

(Kobayashi Comment:  This intriguing Stanford study may offer an answer to Hawaii’s future freshwater shortages…  Imagine routing Hawaii’s torrents of stormwater into the ground aquifers instead of washing brown water pollution onto our beaches and recreation areas…)

Strained by drought in recent years, California desperately needs more resilient water supplies. An affordable solution that provides a wide range of benefits is within reach, according to a new Stanford study.

“We find that MAR is an effective and affordable way to balance local groundwater decisions with regional and statewide management,” said study co-author Debra Perrone, a postdoctoral scholar with Stanford’s Water in the West program.

Many local communities rely on statewide infrastructure to supplement their water supply. This water is costly and limited in supply, raising a need for cost-effective local storage options.

Managed aquifer recharge allows for local water storage, access and management to a much greater extent than large surface water reservoirs, which are often managed by state and federal entities. Although excess surface water can be limited in some regions of California, treated wastewater and urban stormwater offer sources for MAR that aren’t fully utilized by centralized surface water storage infrastructure.

MAR is particularly well suited to more populous and developed areas that can take advantage of large quantities of treated wastewater and stormwater runoff collected by extensive infrastructure for use in recharge. In more rural areas, MAR using excess surface water can still play an important role in replenishing groundwater basins and guarding against dry times.

“Every year, California lets 1 million acre-feet of treated wastewater flow to the ocean,” said co-author Melissa Rohde, previously a researcher with Water in the West. “Our research shows it would cost the state about $870 million to build the necessary MAR facilities to recover and store this water. That’s not a lot of money compared to the cost and energy required to transport water from large surface water projects or to desalinate ocean water.”

A water enigma

Groundwater supplies up to 60 percent of California’s water supply during dry years. Despite its crucial role in slaking the Golden State’s thirst, groundwater went largely unregulated until the 2014 passage of the Sustainable Groundwater Management Act. Therefore, statewide data on groundwater management generally and managed aquifer recharge projects specifically has been sparse or proprietary, generally not shared publicly.

This lack of information was highlighted with the 2015 passage of California’s largest-ever water-related proposition — the $7.5 billion Proposition 1. The bond promises almost $3 billion for water storage projects. Without data on relative costs and benefits, state and local water managers are hard pressed to make informed decisions on MAR projects.

In addition to new funding opportunities, the 2014 law puts the burden on local agencies for sustainably managing groundwater. So, local communities have more reason than ever to bank water sustainably. Managed aquifer recharge allows agencies to do that in ways tailored to a community’s resources.

Perrone and Rohde set out to identify costs and benefits of MAR projects around the state by mining applications for general obligation bonds from ballot propositions. In these publicly available forms, the researchers identified proposed economic costs and anticipated MAR project benefits. Then, they surveyed the projects’ managers to compare initial estimates with actual costs, and to identify advantages and limitations.

Looking to the future

As a changing climate, growing population and other factors put increasing pressures on water supplies, California’s need for long-term resilience will only intensify, the study noted. Conservation will only go so far. Flexible water storage options that can address changing conditions are essential. Therefore, it is likely that more water agencies will adopt MAR as a local management tool.

Story Source:

The above post is reprinted from materials provided by Stanford University. The original item was written by Rob Jordan. Note: Materials may be edited for content and length.

Journal Reference:

  1. Perrone, Debra; & Merri Rohde, Melissa. Benefits and Economic Costs of Managed Aquifer Recharge in California. San Francisco Estuary and Watershed Science, July 2016

Swimming safety: Newspaper analysis shows bacteria levels up, but (Big Island) beaches still within limits

July 2016
  • (Kobayashi Comments: I have elected include this in a freshwater news site because it touches on some issues which are also key to the freshwater issue.  According to the 2014 State of Hawaii Water Quality Monitoring and Assessment Report, the Big Island’s freshwater conditions are better than most of the other islands.  However fully a third of the streams on the island are listed as “impaired” which means one or more of their pollution measurements do not meet EPA standards and are being watched.
  • The good news is about 40% meet EPA standards for cleanliness while the remaining 30% are unobserved.  Similar to the problems cited in the beach article, sampling programs have been cut and collection is limited.  So now here is the beach article…)
By Nancy Cook Lauer West Hawaii Today ncook-lauer@westhawaiitoday.com

KAILUA-KONA — Michael Kahookaulana connects a long green garden hose to a faucet behind the lifeguard stand at Laaloa Bay Magic Sands beach and rinses himself off before turning the hose on his dripping baby and bikini-clad wife.

A local and longtime surfer, Kahookaulana knows the importance of promptly removing the saltwater, sunblock residue and whatever else is lurking in the turquoise waters at one of the Big Island’s most popular beaches.

He also has a good idea — even without looking at the data provided by the state — which of the island’s beaches are cleanest, and when is the best time to avoid them.

“Here, there’s a lot of oil from suntan lotion,” he said Thursday. “On the Hamakua coast, you get river water mixed in and whatever it’s bringing down from the fields. … The quality of the water, you can really tell. I definitely know the water all around the island.”

So does Neil Mukai. The only state environmental health specialist on the island charged with water sampling, Mukai spends his workday driving his state truck beach-to-beach, surf-spot-to-surf-spot, dipping up water in his battered metal bucket.

Despite some short-term spikes in fecal bacteria, waters around the Big Island show levels well below those considered unsafe. But most of the average readings for enterococci — the primary measure of contamination used by the U.S. Environmental Management Agency — have been steadily increasing over the past 10 years.

In fact, average beach fecal bacteria levels have increased five-fold between 2006 and 2016 at key West Hawaii beaches and 134 percent on the Hilo side.

See the rest of the article here…

(Big Island’s) Pohakuloa Training Area told to replace cesspools

June 2016, By Graham MilldrumWest Hawaii Todaygmilldrum@westhawaiitoday.com

KAILUA-KONA — The Army is paying $100,000 for keeping eight large capacity cesspools open a decade after the EPA ordered the closure of all cesspools of that size.

And it could be fined more if it keeps the cesspools open passed certain deadlines.

In a consent agreement announced Tuesday, the EPA said the cesspools can handle waste from 20 or more people a day, have an open bottom and may have perforated sides. They are distinct from the ones used in homes, and the EPA ordered all such large capacity cesspools closed by April 5, 2005, as “untreated sanitary waste from cesspools can enter ground water and contaminate drinking water sources.”

The cesspools provide no treatment for the waste and allow nitrates and human fecal bacteria into groundwater, the agency wrote.

The agreement says there were 12 cesspools active after the required closure date: four at Wheeler Army Airfield/Schofield Barracks on Oahu, and six at Pohakuloa Training Area and two at Kilauea Military Camp on the Big Island. The Army closed the ones at Schofield before the agreement.

The EPA says cesspools are more widely used in Hawaii than any other state, and the EPA has closed about 1,100 of the large capacity cesspools statewide.

Under guidelines published by the EPA, a replacement wastewater system has to be designed by a professional engineer and installed by a licensed contractor.

The cesspools on PTA’s land are to be closed by Sept. 30.

See the rest of the article here…