Evaluation and Reporting on Contaminant Hydrogeological

12-12-01

Conditions at the Tajiguas Landfill

Page 8 of 24

methods of distribution and application of irrigation water, and where and when the

irrigation is performed. In this way it can be determined how much water is lost to

evapotranspiration, evaporation, and the landfill mass itself, etc.

I

NVESTIGATION AND

M

ONITORING CONTAMINANT MIGRATORY PATHWAYS

The current groundwater monitoring system seems inadequate to intercept the

dissolved contaminants in groundwater bypassing the trench. Regulations state that

a sufficient number of groundwater monitoring points must be established to assure

that contaminants cannot bypass the monitoring well network (Article 4, §20415 (D)).

Many springs which have been reported in the Cady Declaration which are

representative of some of the groundwater flow paths not addressed in any

technical documents to date, are supposed to be clearly identified on a map so that

their influence on landfill contaminant migration can be evaluated (Article 4, §21750

(g) (5)). See regulatory reference bellow.

§21750. SWRCB - Waste Management Unit (Unit) Characteristics and Attributes to

be Described in the ROWD. [C15: §2595 & §2547(a) // T14: §17777, §18260, §18263,

& §18264]

(a) Identify Potential Impairment — Dischargers shall provide in the report of

waste discharge (“ROWD”, including any such report integrated into a Joint

Technical Document (JTD), pursuant to §21585) an analysis describing how the

ground and surface water could affect the Unit and how the Unit, including how

any waste, if it escapes from the Unit, could affect the beneficial uses of ground

water bodies (including, but not limited to, any aquifers underlying the facility)

and surface water bodies. The RWQCB shall use this information to determine

the suitability of the Unit with respect to ground water protection and avoidance

of geologic hazards and to demonstrate that the Unit meets the classification

criteria set forth in Article 3, Subchapter 2, Chapter 3, Subdivision 1 of this

division (§20240 et seq.).

(g) Hydrogeology.

(1) General — An evaluation of the water bearing characteristics of the natural

geologic materials identified under (f)(2)including determination of hydraulic

conductivity, delineation of all ground water zones and basic data used to

determine the above.

(5) Springs — A map showing the location of all springs within the waste

management facility and within one mile of its perimeter. The map shall be