LB - Yavapai Gaming 1001

Home | Classifieds | Place an ad | Obituaries | Public Notices | Galleries | Opinions | Real Estate Search | 928 Media Lab | Contact Us | Subscribe | Yellow Pages
Prescott Valley Tribune | Prescott Valley, Arizona

home : latest news : latest news October 4, 2015

12/11/2013 12:09:00 PM
Dewey-Humboldt residents learn next steps for Superfund clean up
Dewey-Humboldt resident Nancy Wright signs in for an EPA public meeting and open house and receives answers to her questions from ADEQ Community Involvement Coordinator Wendy Flood. The meeting was about the Superfund’s remedial clean up efforts.
Trib Photo/Briana Lonas
Dewey-Humboldt resident Nancy Wright signs in for an EPA public meeting and open house and receives answers to her questions from ADEQ Community Involvement Coordinator Wendy Flood. The meeting was about the Superfund’s remedial clean up efforts.
Trib Photo/Briana Lonas
Levels of Arsenic in water (parts per billion):
• 0-10ppb - safe

• 11-200ppb - Increased risk

• 200ppb and up - Do not use this water for drinking or cooking

• Get your tap water tested for arsenic and lead if you have a private well.

• If your private well has arsenic levels above 10micrograms per liter, consider installing an in-home water treatment system.

• If you are connected to the public drinking water system, the water provider is required to meet state and federal drinking standards.

• Remove your shoes before entering the house.

• Have your heating/cooling ducts professionally cleaned regularly.

• Wash your hands and your children's hands before eating.

• Wash your homegrown fruits and vegetables before eating.

• Practice smart gardening. Lettuce, radishes, broccoli, Brussels sprouts, kale and cabbage accumulate more arsenic from soils than other garden plants.

• Have your children's blood tested for lead.

Briana Lonas

Residents of Dewey-Humboldt at an open house Saturday learned about the Environmental Protection Agency's (EPA) remediation efforts for the area's Iron King Mine/Humboldt Smelter Superfund Site - a location declared a Superfund in 2008.

EPA Remedial Project Manager Jeff Dhont presented an overview of the area's historical mining and smelter activities that created large amounts of tailings and slag. Tailings are wastes left over after saleable metals are removed from mined ore. Around 1964, part of the mine's tailings pile collapsed, causing contaminants to flow into the Chaparral Gulch, pass downstream, cross Highway 69 and mix with tailings from the Humboldt Smelter.

Now, Dhont said, investigators will take a closer look at the Area of Potential Site Impact that includes the former Iron King Mine property, the former Humboldt Smelter operation across Highway 69 and the areas north of Prescott Street, east past the Agua Fria River and south of the smelter property, to name a few.

"We can't make it all go away, but looking at the health impacts, we need to select a remedial action to clean up the site," Dhont said, referring to the contaminants. He further explained that the investigative team must determine just how toxic the site is by looking at the health and exposure risks, and pick a remediation option with the public's input. The team is still in the remedial investigation stage, he said.

In the coming months, residents will notice plenty of digging activity along the site's landscape, specifically sonic bore rigs designed to dig deep into bedrock. Several areas are slated for digs, including where 3rd Street in Humboldt crosses the Chaparral Gulch where visible mine tailings exist. Workers will also dig the Middle Chaparral Gulch, west of the Humboldt smelter and a large tailings depression south of Prescott Street. The team will drill and sample the borings in addition to adding11 groundwater monitoring wells at depths from 6 to 125 feet.

In addition, the team will collect soil samples in the residential site areas that either did not allow access or were not available in the 2009 study. Dhont said investigators will calculate the sample results using statistics. If a sample tests unusually high for arsenic, for example 500mg/kg, "then we know that something else is going on, but we don't expect to see something that high," Dhont said. The EPA's Low Risk Range for arsenic levels in soil, specific to the Superfund site, is 0 to 145mg/kg.

As to how the contaminated soils may be affecting residents on or near the site, Dhont explained arsenic bioavailability - the percentage of arsenic that remains in the body after ingestion. The area's residential bioavailability has been analyzed at 20 percent, but is not locked in. Investigators will study exposure and risk for each location within the site.

"We're going to make sure we're right about that. The highest we think is 60 percent," Dhont said.

The team then will conduct a feasibility study and make the proposed remediation plan public.

"The 2009 Remedial Investigation report did not answer all of the questions we needed. We are amending it," Dhont said. "The new report should be available this summer."

Clean-up will be similar to past efforts and already the EPA has removed nearly two feet of topsoil from a dozen yards on Sweet Pea Lane and East Main Street, where higher levels of arsenic and lead existed. Workers moved more than 7,000 tons of soil to the old Iron King Mine site, planted native seeds to stabilize the tailings, and applied soil fixative to ash piles at the defunct Humboldt Smelter site to reduce dust.

"Most of the Superfund work we are looking at is much lower than acute toxic levels that would immediately make you sick," he said.

Representatives from the Arizona Department of Health Services and the University of Arizona Superfund Research Program spoke about exposure at the site, for example skin contact with soils; ingestion, such as when children don't wash their hands or home-grown vegetables are washed improperly or by inhaling dust; and drinking water that tests high in arsenic or lead.

In the recent Metals Exposure Study in Homes (MESH) several nearby residences were tested and volunteers submitted blood, urine and toenail samples. Researchers also tested soil and tap water samples. Researchers found a wide variation in levels, said Miranda Loh, a representative of UA Superfund Research. Physical sample results were low - only 1 household in the MESH study tested over 15ppb in lead and the well water tested for arsenic was either at or above safe drinking levels, she said.

Representatives urged private well users to test their water once every three years to determine chemical levels, and once a year for bacteria.

For residents on the Humboldt Water System, the next lead compliance monitoring study is due Sept. 2014, to check chemical levels in the drinking water.

Important contact information:

Environmental Protection Agency

Remedial Project Manager - Jeff Dhont 415-972-3020

Community Involvement Coordinator - Amanda Pease 415-972-3068, toll free 800-231-3075

Arizona Department of Environmental Quality Community Involvement Lead

Remedial Projects Section - Wendy Flood 602-771-4410, toll free 800-234-5677.

For help understanding well water test results, call Jennifer Botsford with the Arizona Department of Health Services at 602-364-3128.

For information on groundwater wells and water treatment systems call the ADEQ at 602-771-4641. Call the Humboldt Water System at 602-771-4641.

For property access permission from the EPA research team (Consent for Access to Real Property), call the EPA toll-free line at 800-231-3075 or Amanda Pease at 800-231-3075.

    Most Viewed     Recently Commented
•   Prescott Valley's population surpasses its neighbor for the first time (1654 views)

•   Rats! Unwanted pets find a home at Urban Forest Park (636 views)

•   Purple Light Nights taking a stand against domestic violence (497 views)

•   Prescott Valley gives artists a weekend home (494 views)

•   GMO-Free group expands to Prescott Valley (451 views)

Reader Comments

Posted: Monday, December 16, 2013
Article comment by: Nathan Lothrop

For more information on reducing your exposure to metals or for information on exposure studies done in Dewey-Humboldt by the Univ. of Arizona, including Gardenroots and MESH, please contact Dr. Sarah Wilkinson at (520) 307-3452. You can also visit for additional information about our research program.

Article Comment Submission Form
Comments are not posted immediately. Submissions must adhere to our Use of Service Terms of Use agreement. Rambling or nonsensical comments may not be posted. Comments are limited to Facebook character limits. In order for us to reasonably manage this feature we may limit excessive comment entries.
Submit an Article Comment
First Name:
Last Name:
Anti-SPAM Passcode Click here to see a new mix of characters.
This is an anti-SPAM device. It is not case sensitive.

Advanced Search

HSE - We want to hear from you

Find It Features Blogs Milestones Extras Submit Other Publications Local Listings
Classifieds | Place an ad | Public Notices | Galleries | Opinions | Real Estate Search | Contact Us | Subscribe | e-newsletter | RSS | Site Map
LB - House Cookie contest

© Copyright 2015 Prescott Newspapers, Inc. The Prescott Valley Tribune is the information source for Prescott Valley area communities in Northern Arizona. Original content may not be reprinted or distributed without the written permission of Prescott Newspapers, Inc. Prescott Newspapers Online is a service of Prescott Newspapers, Inc. By using the Site, ®, you agree to abide and be bound by the Site's terms of use and Privacy Policy, which prohibit commercial use of any information on the Site. Click here to submit your questions, comments or suggestions. Prescott Newspapers Online is a proud publication of Western News&Info Inc.® All Rights Reserved.

Software © 1998-2015 1up! Software, All Rights Reserved