After spending a few weeks in paradise, many people dream of staying put — making the vacation spot their full-time home.

For a young engineer fresh out of school 35 years ago, the dream came true. As soon as Jeffrey Pearson, P.E., graduated from the University of Minnesota in 1981 with a degree in engineering, he jumped on a plane and flew to Hawaii, where his older sister was on vacation and had space for him to bunk down.

When his sister went home a few weeks later, he stayed behind. Today, Pearson is director of the County of Maui Department of Water Supply. He holds the reins on a collection of separate water systems serving diverse needs and drawing on diverse resources for a county unlike almost any other that people on the mainland might imagine.

Last year, Pearson’s contributions to the water industry were recognized when he received the George Warren Fuller Award from the Hawaii Section, AWWA. The award cited his work on key water supply issues in Hawaii and his volunteer efforts in AWWA leadership and educational programming.

Twists and turns

When Pearson decided to stay in Hawaii, he had no plan for the move and no leads for a job in engineering. So he worked where he could, often on construction and in other fields related to his education. In the meantime, he searched for a job in his area, finally landing one with a small engineering firm. That enabled him to earn the hours he needed under the supervision of a licensed engineer to earn his Professional Engineer credential.

Pearson worked as an engineer-in-training from 1989-91 at Norman Saito Engineering in Wailuku, Maui. Along the way he supported engineers on drainage and waterline designs and conducted field inspection during construction of 36-inch waterline for the Maui department he now leads. He also studied for and passed the two eight-hour tests required by the University of Hawaii to earn his degree in public engineering in 1994.

During the 1990s and through the turn of the century, Pearson worked with two engineering firms, mostly working on water and wastewater projects. In 2003, he joined the Maui Department of Water Supply as deputy director. There he managed three of six divisions, overseeing about 90 team members, involved in operations, water quality and water treatment. He also worked on the utility’s budgets and was a liaison with state water quality officials.

Pearson left the county’s payroll in 2005 but stayed in the county as water manager for the privately owned Kapalua Water Co. There he managed island-wide private nonpotable and potable systems while continuing to work closely with county and state agencies on water issues, compliance and rates.

Pearson stayed with the private company through 2011, when he was named head engineer for the Maui water department’s Capital Improvement Section. In the position, he oversaw $20 million to $30 million per year in construction projects while working with the department leaders and the county council on the utility’s budget. He also coordinated land management, easements and property acquisition.

In 2015, Pearson became deputy director of the Hawaii Department of Land and Natural Resources, overseeing all surface and groundwater sources in the state. It was an interesting position, but the county water department held an even stronger attraction, and he returned as director in 2018.

Multiple systems

Although Maui County bears the name of Hawaii’s third largest island, the county borders cross several ocean channels to encompass the neighboring islands of Moloka‘i, Lana‘i, Kaho‘olawe and Molokini, the last two uninhabited.

The Department of Water Supply operates water production and distribution systems on the two most populous islands, serving 37,000 metered customers on Maui and 7,000 on Moloka‘i. Lana‘i has a single landowner, and its water system is privately operated.

Within that territory, the department operates six distinct water systems, serving the business and tourism hubs in the central area including the county seat of Wailuku, as well as a number of smaller communities.

Besides supplying water to nearly 170,000 residents, the department sees to the needs of substantial numbers of tourists. In 2019, before the COVID-19 pandemic, the average daily count of tourists in Maui County was more than 66,000, adding up to 2.9 million annual day visitors. The resorts also place a heavy demand on the system to maintain their lush landscaping, a need that has continued through pandemic.

In addition to the county’s largest towns, Pearson’s department operates water systems for small villages and farming communities on Maui, several on the east side of the island away from the business hub and several more well above the beaches in the “up country” mountainous core of the island.

To meet the needs of the county, there are four water treatment plants operated by the DWS system: Kamole Weir, Piiholo, Olindo, Lahaina, Mahinahina and Iao.

From the ground

The county’s most predictable freshwater reserves sit under its mountains in aquifers, often at elevations higher than the coastal communities and resorts. The majority of the groundwater is considered basal aquifer; when tapping the aquifers, the department relies on nature to do the groundwater treatment and storage. The water in Maui’s basal aquifers is well filtered as it drains through the island’s volcanic soil and collects in a stable stratum of pure water, essentially floating atop the denser salt water that reaches the water table from the Pacific Ocean.

Well depths can range from 300 to 1,500 feet deep. Due to the salt water, the wells actually draw freshwater from depths that are above sea level. “The water is of such good quality that we don’t really have to treat it,” Pearson says. “We just add a little chlorine as a precaution for disinfection in the distribution system.” The chlorination is done at the 50 well sites before the water is transported to the distribution network.

The department saves significant money because it doesn’t need to treat the well water, but it cannot rely on that source alone. A recent statewide study of water resources calculated the volume of water that can be taken from aquifers without damaging the natural balance between the volcanic surface and the saltwater base. 

Dual source

The Maui Water Use and Development Plan required by the state Commission on Water Resource Management studied the county’s aquifers and the water rights for domestic use, traditional and customary practices, keeping the water in its natural state, and fulfilling the needs of the Department of Hawaiian Home Lands, before setting out a proposal focused on meeting customer demands while maintaining the health of the resources.

Although protection of the aquifers is a key factor in the decision to use both well water and surface sources, Pearson says another reason for the dual systems is that the surface water can be stored and transported at low cost through ditch and pipeline systems originally built to serve the pineapple and sugar cane growing that once covered much of Maui.

It actually costs more to transport the well water from the mountainsides to the distribution systems than it does to treat the surface water in treatment plants, but the well water becomes an important resource during the drier spring months when surface water is not enough to meet the demands.

With either source, Pearson says his system has a key advantage. In most of the system the source elevation is high enough above the population centers that the water flows by gravity. Even though the system’s newest facility, the Iao Water Treatment Plant, requires a 30 psi head pressure, the natural surface water pressure actually has to be reduced before it reaches the microfiltration facility.

Ready for the future

With the opening of the Iao plant in 2019, Pearson’s department increased its peak water capacity to 28 mgd. “It replaces a temporary plant that operated with no protection from the elements for more than 10 years,” Pearson says. “The new plant is state of the art with a capacity of 5 mgd.”

The Iao plant treats water from the Wailuku River; it is diverted to the facility by a private water delivery company. The system’s Kamole and Lahaina plants also use microfiltration. The Piiholo system is a sand filter plant, recently refurbished to provide up to 6 mgd. The county moved to the microfiltration plants because they are more efficient and easier to maintain.

The Iao plant gives the county capacity to meet serve the growing number of residents and visitors in the Central Maui area for the next five to seven years. Before reaching the limits of the existing system, the department will turn to the Maui Water Use and Development Plan to help determine the source and the location of future water reserves.