If the Alaska Gasline Development Corporation builds its planned liquefaction plant and export terminal in Nikiski, its water will come from the city of Kenai, according to the state-owned corporations’s present plans for the LNG project, which would bring North Slope natural gas to Nikiski through an 800-mile pipeline. Previous plans to supply the plant with water from wells in Nikiski were canceled after test wells underperformed or exceeded government standards for contamination.

In operation, the terminal and plant would need about 150 gallons per minute of fresh water — of which 135 gallons would be used for power generation and 15 gallons as potable water and for other utility uses, wrote AGDC Communications Manager Jesse Carlstrom in an email. Carlstrom wrote that this would be less water consumption than the existing industrial facilities in the plant area — an inactive fertilizer plant and a smaller, inactive LNG terminal — used when operating. The present LNG terminal — built in 1969 by ConocoPhillips and sold after years of inactivity to Andeavor, owners of a nearby refinery, in February — chilled its gas supply to liquid temperature using a cooling tower fed by water from local aquifers. The fertilizer plant also used an aquifer-fed cooling tower in its operation, Carlstrom wrote. AGDC’s planned facility would liquefy gas using air fin coolers instead, which don’t require water.

In addition to the plant operation, the project will also require a construction camp in Nikiski during the years the liquifaction plant and terminal are expected to be under construction. The construction camp is expected to need more water — about 250 gallons per minute — than the eventual operating facility.

Kenai’s water system presently supplies about an average of a million gallons of water per day, said Kenai Public Works Director Sean Wedemeyer. The construction camp would demand roughly an additional 360,000 gallons per day and the plant in operation 194,000 gallons a day.

The additional demand would require upgrades to Kenai’s water system, Wedemeyer said, though he didn’t know exactly what kind of upgrades or what they are estimated to cost. This spring AGDC plans to release a feasibility study, carried out by an engineering consultant, of using Kenai’s water system to supply the plant. The required work and its cost will be better known after the study is released, Kenai City Manager Paul Ostrander said.

Carlstrom wrote that AGDC plans to shoulder at least some cost.

“AGDC envisions paying the cost to extend the City of Kenai’s water transmission line 6 miles from milepost 14 (where the line currently ends) to milepost 20 (the proposed sited of the liquefaction facility) of the Kenai Spur Highway (as well as any other associated capital expenses and operating expenses),” Carlstrom wrote. “A billing structure and other details still need to be addressed but AGDC anticipates becoming a rate paying customer of the City of Kenai’s water services.”

Other residents and businesses along the Spur Highway between Kenai and the liquefaction plant would also be able to use the new water line.

A previous incarnation of the LNG project — AK LNG, a collaboration between AGDC and ConocoPhillips, ExxonMobil, and BP — planned to draw water from wells on the plant site in Nikiski. AK LNG began testing three such wells in August 2016, simulating the construction camp’s maximum demand by attempting to pump 350 gallons per minute from one well for 10 days, and pumping 1,000 gallons a minute from another well for 8 hours, simulating the needs of emergency firefighting.

Results of well tests between 2014 and 2016 did not favor using local water. One test well couldn’t meet the demand, and several exceeded U.S Environmental Protection Agency standards for arsenic — a long-time problem for groundwater users in the Cook Inlet region, including the city of Kenai, resulting from both natural occurrence of arsenic and industrial byproducts. Another contaminant found in the groundwater — the industrial solvent trichloroethene — exceeded the Alaska Department of Environmental Conservation’s standards.

Reach Ben Boettger at ben.boettger@peninsulaclarion.com.