News
Mine well draws dust citation: Neighbors fear aquifer will dry up
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| RICK MCCALLUM | Special to the green valley news Pima County Supervisor Ray Carroll, right, speaks Friday with engineer Colin McKenzie at a test well in Sahuarita Heights that would serve the proposed Rosemont Copper mine on the east side of the Santa Rita Mountains. |
By Philip Franchine, Sahuarita Sun
A Sahuarita Heights test well that would serve the proposed Rosemont Copper mine was issued a dust control citation Friday by the Pima County Department of Environmental Quality.
However, the contractor applied water to the site and resumed pumping water Saturday, officials said.
The PCDEQ issued a stop-work order about 6 p.m. Friday, but work had already stopped for the day, PCDEQ Director Ursula Kramer said.
The PCDEQ air program manager, Teresa Sobolewski, arrived Saturday morning to ensure compliance with county dust control rules and verified that the contractor had used a water truck to spray the area, which allowed work to resume, Kramer said.
The well site is north of Dawson Road on the west side of Alvernon Way.
The department also expects to issue a notice of violation by next week, which could result in penalties, Kramer said.
The site was visited for several hours Friday by Pima County Supervisor Ray Carroll, who said the drilling was generating severe dust that was aggravating respiratory problems for neighbors.
Carroll noted that while he represents District 4, including Green Valley, he was called by neighbors of the site, which is in District 2.
Carroll said there were up to three inches of dust on the site, and the dust issue illustrates the problems represented by the mine’s plan to use groundwater from the Sahuarita area for a proposed copper mine on the east side of the Santa Rita Mountains.
Jaime Sturgess, vice president of Rosemont Copper, a subsidiary of Augusta Resource, said that his company was assured by the contractor that they had obtained all required permits and said Augusta takes the matter very seriously.
“This example does show that when working in Pima County, one has to be always as zealous as possible in complying with each and every regulation,” Sturgess said.
The permit issued to Rosemont from the Arizona Department of Water Resources will allow it to pump up to 3 acre-feet of water, about 1.3 million gallons, from a 1,200-foot-deep well “to determine aquifer parameters and potential well production.”
The company wants to pump groundwater from Sahuarita Heights to the mine, while bankrolling a Central Arizona Project pipeline to Green Valley that would recharge the aquifer.
Sturgess said Rosemont plans to locate between five and eight production wells on a 50-plus-acre parcel of land north and west of Alvernon and Dawson and that it has filed a plan of operation that requires it to pump 100,000 acre feet of water over a 20-year period while recharging the aquifer with 105,000 acre-feet.
An acre-foot is the volume of water that would cover an acre one foot deep, or about 325,000 gallons.
Neighbor Thomas Perry, who relies on a water well about 300 feet deep, said he is concerned that Rosemont’s plan to pump water from one or more deep wells in the immediate area will drop the water table for about 100 residential customers.
“It will dry us out,” Perry said. “All the wells in the area are in the 300- to 350-foot range in depth. Our aquifer is not a big underground cavern filled with water. It’s more like a sponge. When you drop a well down at 1,200 feet, you are sucking water out. There are over 100 private wells in the area.”
Perry said residential wells by law only can pump 30 gallons a minute, a slow enough rate to allow the spongy aquifer to fill back up, but Perry said the deeper well, pumping up to 1,000 gallons per minute, will suck out water faster than it can move back in and will create what hydrologists call the “cone of depression” where the water level is lower than in surrounding areas.
Fears wells will dry up
“They will dry up our wells and FICO’s wells and those of the people over by I-19. It’s not going to happen overnight, I understand. It might take 10 years or 20 years, but it will happen,” Perry said.
Sturgess said that Rosemont’s plan to recharge the aquifer with more water than it draws out means the mine wells will not reduce the aquifer.
“I understand their concerns and we will give assurances to them. We will have hydrologic modeling during two years of public review. We will conduct open discussions with concerned people and answer their concerns,” Sturgess said.
Farmers Investment Co., which owns 6,900 acres of pecan groves, and Farmers Water Co., which serves about 2,000 customers, have filed formal objections with the Arizona Department of Water Resources to a Rosemont well at Davis and Delgado streets about a mile west of the well at Dawson and Alvernon.
The Oct. 30 letter from the law firm Snell & Wilmer says “pumping levels proposed by Rosemont Copper Co. could cause an additional 150 feet of drawdown over a 20-year period on FICO lands in the vicinity of this 50-acre tract.
“This additional drawdown may also cause the migration of a sulfate plume from mining operations located to the west of FICO property with the resulting intrusion of sulfate-laden water into both the agricultural and municipal supply wells of FICO and FWC.”
The Oct. 30 letter also argues that CAP water is available for use at the mining operation; that treated effluent may be available for the proposed mine from either the town of Sahuarita or the Pima County Green Valley wastewater treatment plants, noting that the town plant generates 220,000 gallons of effluent per day and the county plant 1.6 million gallons per day.
Sturgess said, “We invited FICO to cooperate with us in bringing a recharge center closer to the production well field.”
A Sept. 13 letter to the AWDR from Rosemont law firm Maguire & Pearce says that while the mine plans to pump water from the Sahuarita area to the proposed mine, “Rosemont does not intend to drill the production wells on the property where the hydrologic test well is located at this time,” but will be constructed after Rosemont obtains another permit.
Sturgess said that, in fact, the test wells also will be used as production wells later on.
pfranchine@sahuaritasun.com
Coming Friday
Community Water Company President Arturo Gabald—n writes on our Comment page about the deal to bring CAP water to Green Valley.
However, the contractor applied water to the site and resumed pumping water Saturday, officials said.
The PCDEQ issued a stop-work order about 6 p.m. Friday, but work had already stopped for the day, PCDEQ Director Ursula Kramer said.
The PCDEQ air program manager, Teresa Sobolewski, arrived Saturday morning to ensure compliance with county dust control rules and verified that the contractor had used a water truck to spray the area, which allowed work to resume, Kramer said.
The well site is north of Dawson Road on the west side of Alvernon Way.
The department also expects to issue a notice of violation by next week, which could result in penalties, Kramer said.
The site was visited for several hours Friday by Pima County Supervisor Ray Carroll, who said the drilling was generating severe dust that was aggravating respiratory problems for neighbors.
Carroll noted that while he represents District 4, including Green Valley, he was called by neighbors of the site, which is in District 2.
Carroll said there were up to three inches of dust on the site, and the dust issue illustrates the problems represented by the mine’s plan to use groundwater from the Sahuarita area for a proposed copper mine on the east side of the Santa Rita Mountains.
Jaime Sturgess, vice president of Rosemont Copper, a subsidiary of Augusta Resource, said that his company was assured by the contractor that they had obtained all required permits and said Augusta takes the matter very seriously.
“This example does show that when working in Pima County, one has to be always as zealous as possible in complying with each and every regulation,” Sturgess said.
The permit issued to Rosemont from the Arizona Department of Water Resources will allow it to pump up to 3 acre-feet of water, about 1.3 million gallons, from a 1,200-foot-deep well “to determine aquifer parameters and potential well production.”
The company wants to pump groundwater from Sahuarita Heights to the mine, while bankrolling a Central Arizona Project pipeline to Green Valley that would recharge the aquifer.
Sturgess said Rosemont plans to locate between five and eight production wells on a 50-plus-acre parcel of land north and west of Alvernon and Dawson and that it has filed a plan of operation that requires it to pump 100,000 acre feet of water over a 20-year period while recharging the aquifer with 105,000 acre-feet.
An acre-foot is the volume of water that would cover an acre one foot deep, or about 325,000 gallons.
Neighbor Thomas Perry, who relies on a water well about 300 feet deep, said he is concerned that Rosemont’s plan to pump water from one or more deep wells in the immediate area will drop the water table for about 100 residential customers.
“It will dry us out,” Perry said. “All the wells in the area are in the 300- to 350-foot range in depth. Our aquifer is not a big underground cavern filled with water. It’s more like a sponge. When you drop a well down at 1,200 feet, you are sucking water out. There are over 100 private wells in the area.”
Perry said residential wells by law only can pump 30 gallons a minute, a slow enough rate to allow the spongy aquifer to fill back up, but Perry said the deeper well, pumping up to 1,000 gallons per minute, will suck out water faster than it can move back in and will create what hydrologists call the “cone of depression” where the water level is lower than in surrounding areas.
Fears wells will dry up
“They will dry up our wells and FICO’s wells and those of the people over by I-19. It’s not going to happen overnight, I understand. It might take 10 years or 20 years, but it will happen,” Perry said.
Sturgess said that Rosemont’s plan to recharge the aquifer with more water than it draws out means the mine wells will not reduce the aquifer.
“I understand their concerns and we will give assurances to them. We will have hydrologic modeling during two years of public review. We will conduct open discussions with concerned people and answer their concerns,” Sturgess said.
Farmers Investment Co., which owns 6,900 acres of pecan groves, and Farmers Water Co., which serves about 2,000 customers, have filed formal objections with the Arizona Department of Water Resources to a Rosemont well at Davis and Delgado streets about a mile west of the well at Dawson and Alvernon.
The Oct. 30 letter from the law firm Snell & Wilmer says “pumping levels proposed by Rosemont Copper Co. could cause an additional 150 feet of drawdown over a 20-year period on FICO lands in the vicinity of this 50-acre tract.
“This additional drawdown may also cause the migration of a sulfate plume from mining operations located to the west of FICO property with the resulting intrusion of sulfate-laden water into both the agricultural and municipal supply wells of FICO and FWC.”
The Oct. 30 letter also argues that CAP water is available for use at the mining operation; that treated effluent may be available for the proposed mine from either the town of Sahuarita or the Pima County Green Valley wastewater treatment plants, noting that the town plant generates 220,000 gallons of effluent per day and the county plant 1.6 million gallons per day.
Sturgess said, “We invited FICO to cooperate with us in bringing a recharge center closer to the production well field.”
A Sept. 13 letter to the AWDR from Rosemont law firm Maguire & Pearce says that while the mine plans to pump water from the Sahuarita area to the proposed mine, “Rosemont does not intend to drill the production wells on the property where the hydrologic test well is located at this time,” but will be constructed after Rosemont obtains another permit.
Sturgess said that, in fact, the test wells also will be used as production wells later on.
pfranchine@sahuaritasun.com
Coming Friday
Community Water Company President Arturo Gabald—n writes on our Comment page about the deal to bring CAP water to Green Valley.
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