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Well underground: NID board poses questions about possible impacts to water wells

Eric Gibbons points to where his 700-foot deep residential well is located outside of his rural Grass Valley home. He is concerned that Rise Grass Valley’s plans to dewater and reopen the Idaho-Maryland Mine will also dewater his well.
Photo: Elias Funez

The general manager of the Nevada Irrigation District told the board it had one duty — to determine if NID’s current and future capacity could provide for the water needs of 31 additional customers.

Those 31 would-be customers need NID water because of the proposed Idaho-Maryland Mine. County consultants have determined that the mine would lead to mitigation efforts for those people.

On Wednesday, they got the approval needed from the NID board, but not before some questions were asked.

Division 4 Director Laura Peters, whose background is in civil engineering, said the potential impacts of the project are relatively mild given a 1996 draft environmental impact report from EmGold, a company that unsuccessfully tried to reopen the mine.

Peters asked how county consultants determined the Idaho-Maryland Mine would require mitigation efforts to only 31 wells, given that a report conducted 25 years before indicates over 100 wells would tentatively need to be replaced by new NID connections if the mine were to be reopened.

Houmao Liu, a Itasca hydrogeologist who helped design the model used to determine where mitigation efforts would be necessary, said even experts expect certain uncertainties in ground flow water models. Liu said the unknowns increase when trying to quantify the impact of climate change.

Eric Gibbons’ rural Grass Valley water well was one of many that a previous environmental impact report showed would be dewatered if the Idaho-Maryland Mine were reopened. An EIR out for the current efforts to reopen the mine does not show Gibbons’ well is in jeopardy, which he says makes no sense.
Photo: Elias Funez

Liu said the previous model used by EmGold-related consultants was two dimensional, and that this time experts used a 3D groundwater flow model that is approved by Nevada’s Environmental Protection Agency.

Peters said she is sensitive to differences between the physical contours of the project — of the land use, available technology and infrastructure — but noted that climate change was not on anyone’s radar in the 90s.

Nick Pappani, Raney Planning & Management’s vice president and a hired consultant for the county, said thinking of available groundwater as contained by a vertical water column is a useful image to employ when considering well mitigation efforts.

Pappani said seven to 12 domestic wells in the East Bennett area could be impacted by a 10% reduction, but that the threshold for significant impact actually ranges from 20% to 40%, if regular seasonal fluctuations are taken into account.

The Idaho-Maryland Mine draft environmental impact report is available for the public to read and make comments on. The end of the comment period is April 4.
Photo: Elias Funez

Some of the wells could be deepened, Pappani said, but Rise Grass Valley — the company seeking to reopen the mine — may need NID to lay new pipes to reach residences with limited mitigation options.

Pappani said Rise Grass Valley expanded its mitigation efforts beyond the minimal requirements.

“The applicant has committed to serving a greater number of wells around (the seven identified),” Pappani said.

Page 4.8-3 of the Idaho-Maryland Mine’s draft environmental impact report. The draft EIR notes that the Idaho-Maryland Mine project sites are located within two watershed area, the Centennial Industrial Site in the Upper Wolf Creek watershed and the Brunswick Industrial Site located in the South Fork Wolf Creek Watershed, which is upstream of a culvert where the creek passes underneath part of the city of Grass Valley.

District 5 Director Rich Johansen said the tests go “against everything his grandparents taught him,” given that water availability varies greatly if one draws water from a well for 30 minutes or four hours.

Other meeting attendees questioned the language used by consultants, and asked if NID would identify the mine as a “net water producer’ if it were to author the report.

“Rise Gold’s claim that they will be a ‘net water producer’ by pumping groundwater is false and misleading,” said Keiko Mertz, with the South Yuba River Citizens League, adding moments later, “Well users who can no longer access groundwater will become dependent on our already limited supply of water.”

Rebecca O’Neil is a staff writer with The Union. She can be reached at roneil@theunion.com

Eric Gibbons’ rural Grass Valley home and others possibly affected by the reopening of the Idaho-Maryland Mine may have to be supplied by Nevada Irrigation District water if his well, and the ground beneath him, becomes dewatered.
Photo: Elias Funez

This story was updated to reflect the correct date the public comment period ends

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