The Alaska LNG Project is moving forward with an aquifer pump test on its land in Nikiski this summer.
The project, a collaborative effort between ConocoPhillips, ExxonMobil, BP and the state of Alaska to bring natural gas on the state’s North Slope to market, has conducted geophysical and geotechnical work on the proposed site of its plant in Nikiski since 2013. As part of this year’s approximately $230 million fieldwork season, the project engineers will drill test and observation wells on its property in Nikiski in preparation for water testing.
The current plan is to drill three wells total, possibly with two of them co-located, said Jeff Raun, the project advisor for the Alaska LNG Project.
The work will begin with two wells drilled to similar depths, drawing from one aquifer below Nikiski, and if it is possible, one of the wells will be deepened, he said.
“Our reason for the second test into that lowermost aquifer is to prove our ability for that lowermost aquifer to recharge our fire water tanks after construction,” Raun said. “If we ever needed to refill those fire water tanks, there’s a requirement to do so over a certain period of time. That’s the reason for that shorter-duration test.”
Water use has been a concern for many residents of Nikiski throughout the project.
The groundwater in Nikiski has been historically contaminated by industry processes, illegal dumping and unauthorized waste disposals, and the Kenai Peninsula Borough commissioned a study on the area’s water to find out more both about the contamination and about the subsurface geology.
The study, released to the public in April 2015, illuminated the structure of two distinct aquifers under Nikiski. The upper aquifer is affected more by local drawdown, according to the report.
Further geophysical work has shown a third aquifer below the upper two, more confined and larger, Raun said at a public meeting in April.
Though the project engineers do not expect there to be an impact to local residents based on the test, that’s one of the reasons for the test, he said.
Up until now, the planners have relied on “desktop” information about the aquifers and water quality in the area, but this summer they will be able to obtain more data through the monitoring wells and pump tests, he said.
Natural Resource Manager Henry Brooks of the Alaska Department of Natural Resources, who had a part in authorizing the studies, said his department would look at the effects of the Alaska LNG Project’s water use on the quantity of water from wells within about a quarter mile of the site.
Brooks said that currently his department doesn’t have a great amount of data regarding the Nikiski area aquifers.
“Until they take a test, we won’t know a lot of the questions we want to ask, because there’s not a lot of data in Alaska,” Brooks said. “For us, the test is a benefit... They’re looking for three aquifers, and we’re looking to see if those aquifers are separate. We won’t actually know until they do the test.”
Based on a pre-test look at the project, Brooks said he didn’t expect local wells to be affected by the study.
“Generally, the deeper the well and the greater the distance (from other wells), the less likely the impact,” Brooks said. “And we didn’t see with (AK LNG’s) depth and distance any indication that there was going to be any clear issues... Most of the (existing) wells are shallow — 25-30 feet at best. You have a few that go beyond that, but only two are in the 100-foot range, and they don’t appear to be in proximity to the test wells that AK LNG is talking about.”
Raun said this summer’s tests would be relatively brief.
“…This year, in listening to the community’s concerns, we’ve stepped forward and prepared an aquifer pump test program to install wells to pump the aquifers over a short period of time, and observe what happens when we pump that water so we can get closer to seeking a solution that doesn’t impact the existing users of water in the area,” Raun said.
The pump test will begin with a 10-day test out of the second aquifer, taking 350 gallons per minute and channeling it to a currently unused quarry the Alaska LNG Project owns in Nikiski, Raun said. The 350 gallons per minute reflects the maximum possible need during construction, though the draft resource report submitted to the Federal Energy Regulatory Commission states that number as approximately 250 gallons per minute for construction and potable water.
After that, either one of the wells will be deepened or a new, deeper well will be drilled to the lower aquifer, estimated to be at 250 feet below the surface.
The test from the lower aquifer will be shorter but more intensive, drawing 1,000 gallons per minute for eight hours, he said.
The water will be sent to the quarry, where the project engineers think it will infiltrate into the ground, he said.
“We‘ve done some minimal infiltration rate tests in that pit, and the infiltration rates are positive,” Raun said. “We don’t anticipate that that water, once it’s pumped, won’t stick around for very long.”
The plan is to begin drilling the observation wells as early as this week and possibly start the first tests in late August.
The project engineers will monitor the water levels in the surrounding area, both on the surface and sub-surface, to watch for the impacts.
Paired observation wells will be installed in two locations upgradient of the proposed plant site so the engineers will have a chance to study what is happening upgradient of the pump test.
One of the concerns locals have brought forward is the water level on Cabin Lake, which sits just northeast of the Alaska LNG property and is surrounded by private land.
Raun said the project engineers would install gauges to watch the water levels and account for rainfall and natural surface water fluctuation.
They will also test for quality measures like alkalinity, pH and turbidity, as well as for metals and other things “that we wouldn’t expect to find,” like organics or volatiles, Raun said.
The other fieldwork is wrapping up. Earlier in the season, an offshore vessel conducted bathymetry on the floor of Cook Inlet to gather more information for the proposed pipeline route. The ships completed their work by the end of June, getting out of the way of the drift gillnet fishermen and the set gillnet fishermen in the area for the season as well as other shipping traffic and wildlife.
Onshore borehole drilling is still going on, picking out locations for heavy equipment like storage tanks and testing the ground beneath transfer sites. Property purchasing is ongoing as well, said Matt Horneman, the deputy land manager for the Alaska LNG Project.
The contractors will continue to tear down structures on the land as well — there are more than 20 demolitions scheduled for this year, he said. In response to concerns about security, the managers have upped the security patrols in the area, making the rounds at least twice per day, he said.
“It depends on when properties sell as to when they’re actually demolished,” Horneman said. “…This year, we’ll be knocking down every house that’s available.”
The fieldwork contributes more data to the resource reports the project managers will submit to the Federal Energy Regulatory Commission.
Currently, Resource Drafts of reports one and 10 — outlining the general overview of the project and possible alternatives, respectively — have been submitted, and draft reports two through 9 are in the works to be submitted in the next month or so, said Josselyn O’Connor, the community stakeholder advisor for the project.
Reach Elizabeth Earl at email@example.com.