DSHW-2013-001770 - 0901a06880349e83

r u o im -> Division of February 8, 2013 Solid and Hazardous Waste
FEB 0 8 2013
Mr. Scott T. Anderson, Director (P-Old?" 0 0 {77 0
Utah Department of Environmental Quality
Division of Solid and Hazardous Waste
195 North 1950 West
P.O. Box 144880
Salt Lake City, Utah 84114-4880
Re: Perchlorate Trend Charts for Selected M-136 Monitoring Wells
EPA ID Number UTD009081357
Dear Mr. Anderson:
ATK Launch Systems ("ATK") is providing perchlorate concentration trend charts for four wells
(A-5, C-1, D-4, and D-6) at the M-136 facility at our Promontory Operations. These wells were
identified in the Utah Division of Solid and Hazardous Waste (the "Division") Operations and
Maintenance report dated December 22, 2011. The Division requested that the analytical data be
evaluated and that a statistical trend test be performed for each well. The Division subsequently
agreed that additional monitoring should be conducted prior to the statistical analysis. The trend
charts include the analytical results from the last half of 2012.
These wells are down gradient of the closed Liquid Thermal Treatment Area that historically
received waste water containing perchlorate. The trend charts show an increase in perchlorate
concentrations in Wells C-1 and D-4, a decrease in perchlorate concentrations in Well D-6, and
no trend in Well A-5. We are uncertain as to why two wells are showing an increasing
perchlorate concentration trend and other wells in the same area do not.
ATK will continue to sample these four wells on a semi-annual basis to determine if these trends
are continuing. We would also be available for further discussion on this matter with Messrs.
Gabert and Vandel. If you have any questions, please contact Paul Hancock at [phone] or
me at [phone].
Sincerely,
Robert Ingersoll, Director
Environmental Services
ATK Launch Systems
Cc: Helge Gabert
Jeff Vandel
ATK Promontory Selected M-136 Monitoring Wells Perchlorate Trend Charts February 2013
A-5 Perchlorate
2000
1000
Sen's Slope - No Trend • Concentration (ug/L)
Sen's Estimate
95% Conf. Max
95% Conf. Min.
y = 48.113xt 5066.8
y = 41.61Sx+3588.5
y = 3S.117x + 2110.3
/////////SS/////S/
Sample Date
C-1 Perchlorate
30O00
Sen's Slope - Increasing Trend • Concentration (ug/L)
——Sen's Estimate
95% Conf. Max
y = 977.87xtS312.4 —95% Conf. Min.
y = 985.6x* 1704.7
y = 993.33x-1903
////////////////////
Sample Date
ATK Promontory Selected M-136 Monitoring Wells Perchlorate Trend Charts February 2013
D-4 Perchlorate
180000
80000
f
& 40000
20000
Sen's Slope - Increasing Trend
y jf jf y ^
Sample Date
y = 5347.3xt 107631
y = 5405.3x + 102171
y«S463.3x+96710
• Concentration (ug/l)
Sen's Estimate
95% Conf M,ix
95% Conf. Min.
D-6 Perchlorate
1 t
Sen's Slope - Decreasing
40000
• Concentration (ug/L)
Sen's Estimate
95% Conf. Max
95* Conf. Mil.
y= 6289.7x» 161029
y = -6S86.3x* 140791
y = -6883x* 120552
/ / / / / / / / / / s«