DSHW-2018-005764 - 0901a06880858f23

DSHW-2018-005764 195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 144880 • Salt Lake City, UT 84114-4880 Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov Printed on 100% recycled paper
State of Utah
GARY R. HERBERT Governor SPENCER J. COX
Lieutenant Governor
Department of
Environmental Quality
Alan Matheson Executive Director DIVISION OF WASTE MANAGEMENT AND RADIATION CONTROL Scott T. Anderson Director
July 12, 2018
Corey Christensen
Western Zirconium 10,000 West 900 South Ogden, Utah 84404-9760
RE: Western Zirconium Plant Pi-3 Replacement Report
UTD092024934 Dear Mr. Christensen:
The Division of Waste Management and Radiation Control has completed its review of the referenced
report dated March 7, 2018. The report addresses groundwater monitoring well Pi-3 and its replacement Pi-3R. Low pH groundwater was encountered during the installation of Pi-3R which triggered an investigation to collect pH values from groundwater at nearby locations. WZ proposed to address the matter of low pH groundwater through Monitored Natural Attenuation for the next three to five years.

The Division also reviewed the Plant Area Semi-Annual Monitoring Report dated May 2018 which documents the pH level at Pi-3R at 1.13 units this year. The Division also reviewed sampling data from 2003 for Pi-3 which reported the pH value to be 1.3 pH units at that time. The Division notes that 15 years have passed without a significant change in pH values at this location.

The Pi-3R report documents that 335 gallons of low pH (less than 1 pH unit) groundwater was reported recovered during the purging and development of Pi-3R without significant drawdown occurring. This provides a rough indication that the hydraulic conductivity is very high at this location. The use of the estimated linear seepage velocity of 54 feet per year obtained from the same report indicates that a plume would have migrated in excess of 800 feet since 2003. This scale of hydraulic conductivity leads
the Division to expect near neutral groundwater conditions to have been encountered at this location after the passage of 15 years. The Pi-3R report provides an evaluation of groundwater flow direction in the vicinity by using three data points, while excluding data from five other nearby wells due to not enough water, too much water,
presence of a mound and the presence of a depression. The reported prevailing flow direction at Pi-3R is from the northwest to the southeast. The 2018 report confidently utilized all data points and reported
a prevailing flow direction from southeast to northwest at this vicinity. The Division notes that the
inconsistency of flow directions obtained mere months apart appears highly unlikely to be caused by a seasonal fluctuation. Division staff visited the site on June 19, 2018 and observed the replacement of a low pH water drain
line at the vicinity of Pi-3 and Pi-3R. The presence of low pH water in the drain line’s secondary
containment prompted its replacement. Visual observations detected no signs of release southeast of Pi-3 and Pi-3R, which may corroborate that this area is not affected by a release. However, if there is a release at Pi-3R and the prevailing flow direction is to the northwest, then a plume could be located under the pickling building where acids are utilized.

The 2018 monitoring report also documents that Pi-3R exceeds the action level for fluoride at 2,850 mg/L and it was only 10 mg/L in 2003. The increase in fluoride and the stability of pH values leads Division staff to suspect that there exists an ongoing release at this location. The applicable groundwater monitoring plan specifies that an exceedance of applicable groundwater action levels or
indications of a release requires corrective action. Both conditions appear triggered.
Division staff also note that constituent concentrations at groundwater monitoring well Pi-3R had the highest site concentrations for the following: Nitrate 2,780mg/L, Nitrate Nitrite 2,700 mg/L, Gross Beta 380 pCi/L, Radium 226 18.4 pCi/L, Radium 228 86 pCi/L, Thorium 230 6.9 pCi/L, Thorium 232 16.8
pCi/L and Uranium 0.0479
ug/L. The discussions above lead the Division to suspect that an ongoing release is occurring. Therefore, the Monitored Natural Attenuation proposal cannot be approved. In accordance with the monitoring plan, a
Corrective Action Plan is now required that addresses the low pH and fluoride contamination and the
other constituents apparently associated with this release. This plan should first focus on assessing and containing the source of the release. In addition, the groundwater flow direction needs to be accurately defined for the placement of potential future monitoring or extraction wells. Please submit a Corrective Action Plan to the Division within 30 days of the date of this letter.

If you have any questions, please call Rolf Johnsson at [phone]. Sincerely,

Scott T. Anderson, Director Division of Waste Management and Radiation Control
STA/RTJ/km
c: Brian Bennion, Health Officer, Weber-Morgan Health Department Michela Harris, Environmental Health Director, Weber-Morgan Health Department Amy Hensley, USEPA Region 8
Phil Goble, Division of Waste Management and Radiation Control