Evaluation and Reporting on Contaminant Hydrogeological

12-12-01

Conditions at the Tajiguas Landfill

Page 19 of 24

21 ppb

4) benzothiazole in MW#3 @ l0 ppb

5) benzene in MW#10 @ 0.79 ug/l; and

6) chlorobenzene in MW#15 @ 14 ppb

No explanation has been provided as to the sources of this contamination in

groundwater.

(97 Correspondence.tif, Image 15)

A May 5, 1998 Regional Board letter to Santa Barbara County Public Works

required that a subsurface investigation must be performed to determine whether

the Landfill is or will be within five feet of underlying groundwater and that

investigation of the buried alluvial zone of Pila Creek should be performed as well.

This has not been addressed. In addition, the Board recommended further

subsurface investigation of the possible VOC contaminant source(s) prior to liner

installation and that a subsurface investigation of whether or not a more

concentrated plume of leachate exists under the western edge and toe of the landfill

to determine if the leachate is mixing with clean groundwater prior to entering the

extraction trench. This has not been addressed either.

(98 Correspondence.tif, Images 64 thru 66)

A May 29, 1998, written notice documented two releases of leachate from a drain

pipe from Landfill's leachate collection system and from an abandoned culvert at the

south end of the waste mass was discharging approximately ten gallons per hour of

contaminated water to Pila creek. Although the drain piping for the leachate system

has been replaced and the culvert drain has been contained by interception and

pumping to existing storage tanks, a long term solution for a long-term solution for

the culvert has not been pursued.

(98 Correspondence.tif, Images 90 thru 92)

A June 19, 1998 Regional Board letter to Santa Barbara County Public Works

issued a NOTICE OF VIOLATION regarding violation of Specification B.5 of Waste

Discharge Requirements Order No. 93-69. Specifically, three instances were outlined

as follows:

1) On December 9, 1997, Board staff inspected the Landfill and issued a Notice

to Comply with Minor Violations based on drainage system problems (a

violation of Discharge Specification B.33).