DOE/ORO/2327 Oak Ridge Reservation Annual Site Environmental ...

Oak Ridge Reservation
Analytical results for the K-31/K-33 area that
exceeded screening levels in samples collected in 2009
are given in Table 3.26. Analytical results from these
samples were used to provide information for
determining if chromium or other metals are present in
storm water discharges in quantities that exceed the
Tennessee Water Quality Criteria. In addition, the total
amount of chromium and other metals in combined storm
water and groundwater discharges to receiving waters
could be determined.
Chromium was detected in the discharge from storm water outfall 590 at a level of 8.1µg/L
(Table 3.26). This exceeds the screening level for chromium, which is 8 µg/L. No previous analytical data
is available for this outfall. Outfall 590 receives discharges from the former location of the K-861 cooling
tower and associated facilities. Including the K-861 cooling tower, there were a total of five cooling
towers that were constructed of either treated redwood or Douglas fir to dissipate the heat from the
recirculating cooling water system to the environment. A chromate/zinc/phosphate treatment was used for
corrosion control. In the 1960s, a Martreat treatment was used to control biological fouling in the cooling
towers. That process reportedly produced copper fluorides, copper chromate, zinc arsenate, and zinc
chromate. The cooling towers were demolished as part of the Cooling Tower Demolition Project, which
was conducted in 1996–1998.
Copper was detected in the discharge from storm water outfall 710 at a level of 10.2 µg/L
(Table 3.26). This exceeds the screening level for copper, which is 7 µg/L. Copper has not been detected
at levels above screening criteria in sampling performed in 2006 and 2007. Outfall 710 receives storm
water discharges from Building K-33, a portion of Building K-31, the former location of the K-792
switchyard, and the K-1065 waste storage facilities. All storm water runoff from Buildings K-31 and K-
33 that enter this drainage system pass through oil skimmer K-897-N before discharging through outfall
710. Buildings K-31 and K-33 are currently inactive. A decision on the final disposition of the buildings
will be made in the future. The K-1065 facility remains active, but no discharges from the facility to the
environment have been reported. The K-792 Electrical Switchyard transferred electrical power to the
K-33 cascade operations. A series of French drains were installed underneath the gravel bed of the
switchyard when it was constructed in 1954. An oil skimmer for storm water runoff was installed in 1981.
All of the equipment has been removed from this switchyard, and it is no longer active.
3.5.1.9 Sampling of the K-702-A Slough
A portion of the Powerhouse area drains to Poplar Creek through the K-702-A slough. This flume is
connected to Poplar Creek by underground piping. Discharges from the Powerhouse area into the
K-702-A slough currently consist almost entirely of storm water runoff.
The K-702-A slough receives storm water runoff from the K-700 Powerhouse and associated area.
The Powerhouse generated and distributed electrical power for Oak Ridge Gaseous Diffusion Plant
operations using fossil fuel fired steam generating facilities. Several storm water outfalls carry storm
water runoff from the general Powerhouse area to the slough. The slough also receives discharges from
the K-720 Fly Ash Pile, which was historically utilized for disposal of fly ash generated by the coal-fired
boilers in the K-700 Powerhouse. Discharges from the K-720 Coal Ash Pile enter the slough via
outfall 992.
Arsenic and selenium have been detected in historical sampling events conducted at outfall 992. Also,
the discharge from outfall 992 has been observed to have a very low pH on several occasions. Runoff
from the K-720 Fly Ash Pile is believed to be the primary contributor of arsenic and selenium to the
discharge from outfall 992. It is also believed to be the source of the low pH discharges from this outfall.
In 1994, the K-720 Fly Ash Pile area was covered with soil and seeded. In 2008, the drainage channel for
runoff from the K-720 area was lined with rip-rap in an effort to prevent the discharge of low-pH runoff
from the ash pile. Elevated levels of arsenic or selenium have not been noted in the K-702-A slough.
3-52 East Tennessee Technology Park
Table 3.26. Storm water results from
K-31/K-33 sampling exceeding
screening levels
Storm water
outfall
Chromium
(µg/L)
590 8.1
Copper
(µg/L)
710 10.2