Evaluation and Reporting on Contaminant Hydrogeological

12-12-01

Conditions at the Tajiguas Landfill

Page 21 of 24

A September 16, 1998, Regional Board comments on the August 12, 1998 Trench

Water Management Plan which disagreed with the County’s statement that, ". . some

of the steps necessary to implement the Proposed Trench System Plan are beyond

the control of the County." The Board also stated that the County’s Plan lacked

information regarding expected flow rates from the system during wet weather.

Specifically, the Board pointed out that their interim plan for spray application of the

collected liquid directly to an area on the western ridge line failed." Using direct

application to land as a primary means of for applying thousands of gallons of water

to already wet slopes may present stability problems, that concentrations of metals

may accumulate in the area of the spray field, that soil samples should be collected

and analyzed, that the proposed monitoring of runoff from the area did not specify

what was going to be monitored, that no criteria had been proposed as to how data

collected would be evaluated, and that no contingency plan had been made to

establish thir course of action if impacts from the spray field are detected.

(98 Correspondence.tif, Images 122 and 123)

An August 27, 1999 Regional Board letter to Santa Barbara County Public Works

stated that control of storm water discharge as required in the Board’s Notice of

Violation issued on June 19, 1998 had still not been completed after more than one

year and that the Board may implement formal enforcement actions. The Board

further stated that the County do not have adequate ability to control sediment-laden

runoff or other unforeseen releases of waste from the landfill.

(99 Correspondence.tif, Image 77 thru 79)

R

ECOMMENDATIONS

The following measures are necessary to ascertain the potential for impacts to

water quality and to determine the need for additional feasible corrective actions and

mitigation measures to reduce such impacts.

1) Define the contacts between the existing landfill mass and all man-made

conduits, all discernable artificial fill, disturbed soils, and formations through field

subsurface investigation. This will reveal conduits for the migration of landfill

contaminants to surface water and groundwater. All subsurface investigation

should be conducted through a conductor casing. A structure contor map of the

bottom of the landfill relative to GW table contout map should be produced to

provide crossesction of the bottom of the landfill relative to the water table.

Enegeneering designs must be developed and implemented for the purpose of