1 - paducah environmental information center

Annual Site Environmental Report for 1999
are installed to monitor groundwater in the
terrace gravels. A summary of the maximum
results for each of the wells is provided in Table
9.4. Complete results of the monitoring were
reported semi-annually in the FFA Semiannual
Progress Report.
Federal Facility Agreement Monitoring
The FFA requires monthly sampling of
residential wells potentially affected by the
contaminant plume (DOE 1998). Currently,
only three residential wells (R2, R294,and
R302) meet this criterion. Eighteen other
residential wells' are monitored semiannually per
the FFA. Additionally, MW 66 (located on site
at the northwest corner of the plant) is required to
be sampled on a monthly basis. All monthly
sampled wells were analyzed for gross alpha and
beta, TCE, and 99'fc. MW66 is sampled annually
for uranium; it was not detected in 1999. As
stated previously, the hydrologic unit in which
residential wells are screened is uncertain;
however, most are believed to be RGA wells.
Table 9.5 provides a summary of the maximum
detected results for the monthly monitoring
programs. Semiannual residential sampling
results yielded no detections of TCE and 99'fc.
Two residential wells, R424 and R432, are
also sampled semiannually. These wells contain
TCE in the groundwater above the action limit of
1 J.1g/L, however, their location makes it highly
improbable that the contaminants migrated from
the Paducah Site. For these wells, DOE has
provided' the residents with a carbon filtering
system to' allow them to have safe drinking
. water. These filters are replaced semiannually
and: sampled before and after filter replacement.
All residents were notified by mail 01 the results.
AdditionaHy, D0Esampied the
groundwater wells of 23 residents that requested
special sampling of their wells during 1999.
These residents were also notified by mail of the
results.
Environmental Surveillance Monitoring
Environmental surveillance monitoring is
defmed as perimeter exit pathway monitoring
and off-site water well monitoring. Environmental
surveillance monitoring is conducted in support
of DOE Orders and other laws and regulations as
addressed in the Paducah Gaseous Diffusion
Plant Environmental Monitoring Plan (BJC
199'8). Specific wells monitored for
environmental surveillance are as follows:
• Annual Monitoring Program -
(UCRS) MWs 96, 180, 182, and 192;
(RGA) MWs 71, 106, 134, 155, 156,
161, 163, 168, 169, 175, 178, 188, 191,
193, 200, 201, 203, 205, and 206;
(McNairy) MW 133;
• Annual Background Monitoring
Program - (Terrace Gravels) MW 196;
(Eocene Sand) MW 305; (RGA) MWs
103, 150, 194, and 199; (McNairy) MWs
102, 120, 121, 122; and
• Quarterly Monitoring Program -
(UCRS) MWs 166, 174, 186, and 187;
(RGA) MWs 20, 63, 65, 98, 99,100,125,
135, 139, 146, 152, 165, 173, 185, 197,
202, 260, 261, 262, 328, 329, 333, 337,
338, 339, 340,341, 342, 343, 345, 346,
347,352, 353, 354, and 355; (McNairy)
MW 356; (Rubble Zone) MWs 345, 346,
and 347.
During 1999, surveiilance wells were
sampled for VOCs, gross alpha and beta activity,
and, '»fc. One well, MW 352, was unable to be
sampled'underthe routine program due to a high
solids content. Special sampling indicates that
MW 352 was not adequately developed to allow
proper sampling. Table 9.6 provides a summary
of the maximum detected results for each
hydrogeologic unit sampled for the surveillance
program. The maximum TCE value reported in
the RGA is 220,000 J.1g/L from MW 156. MW
156 is located at the southeast corner of C-400.
Groundwater
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