Evaluation and Reporting on Contaminant Hydrogeological

12-12-01

Conditions at the Tajiguas Landfill

Page 14 of 24

S

ECTION

C

Numerous violations in the operation of the Tajiguas Landfill have been noted to

occur in the past. The landfill management has not made sufficient effort to correct

many of them. In light of these fact, it is diffucult to imagine that the landfill

operators will be anymore responsible with the expanded landfill. See the following

history of viloations beloow.

A May 25, 1993 Regional board evaluation of the Emcon's June 30, 1992, Article

5 report entitled “Water Quality Monitoring Plan and Financial Assistance Report,”

stated there was a lack of monitoring in the Rincon and Monterey Shale formations

and that a VOC plume could migrate without early detection because their wells do

not have short screened intervals targeting the top and bottom portions of the

aquifers to minimize dilution of the dissolved constituents of concern. The

inadequacy of the groundwater monitoring network has still not been addressed.

The May 25, 1993 Regional Board letter required that a plan to define the extent

of contamination be submitted. This has also never been completed either. Finally,

the Board stated that LANDFILL EXPANSION not be allowed until full compliance

with Article 5 has been attained and that the Article 5 Report for the existing Landfill

was not adequate to incorporate the proposed expansion.

(93 Correspondence.tif, Images 5 thru 9)

A November 29, 1993 Board letter to the County commenting on the County’s

May 1991 "Water Quality Solid Waste Assessment Test report (SWAT report),” it

stated that the Landfill leaked benzene and 1,4-dichlorobenzene concentrations

found in surface water and 1,4-dichlorobenzene was also identifyed in ground water

above the primary MCL as well as metals such as total chromium, manganese, and

iron in groundwater exceeding primary or secondary MCLs which were above

background levels and/or not considered naturally occurring, and therefore are

considered to be a threat to water quality.

(93 correspondence, Image 36)

A January 7, 1994 County letter to the Regional board reported the analytical