SECTION 1.0 

INTRODUCTION 

BRYAN A. STIRRAT & ASSOCIATES 
1.0 INTRODUCTION 

1.1 PURPOSE 

PCFS FCPCMP 

This Final Closure and Post-Closure Maintenance Plan (FCPCMP) for the Picacho 

Cut and Fill Site (PCFS), SWIS No. 13-AA-0012, has been prepared for the 

County of Imperial Department of Public Works (CIDPW) by Bryan A. Stirrat & 

Associates, Inc. The PCFS FCPCMP has been prepared in accordance with the 

Code of Federal Regulations (CFR) Title 40, Part 258, Subpart F. 

The PCFS is located on land occupied by the Quechan Indian Tribe. These Tribal 

lands are held in trust by the federal government and are not under the authority 

of the State of California. Therefore, the Quechan Tribal Council has the 

authority to regulate the Tribal environment. As a result, this FCPCMP for the 

PCFS will be subject to their review and input with final approval and by the 

United States Environmental Protection Agency (USEPA) Region 9 with the 

Quechan Tribal Council's concurrence. Since the PCFS is situated on Indian 

land, the governing Municipal Solid Waste (MSW) landfill regulations for the 

closure of the facility are found in the Federal Code of Regulations, Title 40, Part 

258 (40 CFR 258). However, it should be noted that for certain aspects of the 

closure and post-closure requirements, not specifically outlined in the Code of 

Federal Regulations, California standards (i.e., Title 27 of the California Code of 

Regulations), which are more stringent than the Federal regulations, will be used 

as guidance. 

Certain variations from the federal regulations (i.e., 40 CFR 258) must be 

approved by the EPA as described in a document entitled, "Site-Specific 

Flexibility Requests for Municipal Solid Waste Landfills in Indian Country - Draft 

Guidance" (EPA, August 1997). Included in the guidance document are the 

requirements and instructions for preparing a site-specific flexibility request 

(SSFR) for modifying the list of groundwater monitoring parameters from those 

specified in 40 CFR 258.54(a). Geologic Associates (GLA) has prepared a SSFR 

to modify the list of detection monitoring parameters provided in 40 CFR 

258.54(a)(1) and (2). The groundwater SSFR was prepared based on information 

summarized in the semi-annual water quality monitoring reports prepared by 

GLA for the CIDPW, including the first semi-annual 2009 and the annual report 

dated April 2010, and the EPA (August 1997) SSFR guidance document. The 

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groundwater SSFR (dated September 201 0) is included as Appendix C-1 of the 

FCPCMP. 

In addition, an SSFR has been prepared by GLA to demonstrate that the 

proposed alternative final cover system meets the requirements of 40 CFR 

258.60(b). The final cover SSFR was prepared based on information summarized 

in the Preliminary Alternative Cover Evaluation and Design Report (see Appendix 

D) for the PSWS Final Closure prepared by GLA (May 1999) and the EPA 

(August 1997) SSFR guidance document. The alternative final cover SSFR (dated 

March 2008) is included as Appendix D-1 of the FCPCMP. 

The sections titled Introduction (Section 1.0) and Existing Environmental Control 

and Monitoring Systems (Section 2.0) of this document present information 

which is common to both the Closure Plan (Section 3.0) and Post-Closure 

Maintenance Plan (Section 4.0). The Post-Closure Emergency Response Plan and 

Closure/Post-Closure Maintenance Cost Estimate are presented in Sections 5.0 

and 6.0, respectively. Certification of Closure (Section 7.0), Recordkeeping 

(Section 8.0) and References (Section 9.0) comprise the remaining sections of 

this document. 

1.2 SITE LOCATION 

PCFS FCPCMP 

The PCFS is located in the southeastern portion of the Imperial Valley 

approximately four and one half miles north of Winterhaven and one and a half 

miles north of the All American Canal (Figure 1 ). The site is situated in a rural 

area at the base of the Cargo Muchacho Mountains. The legal description of the 

site by the government survey method is: a portion of the Northeast quarter of 

Section 35, Township 15 South, Range 22 East, San Bernardino Baseline and 

Meridian. The approximate latitude of the site is 32° 48' 51" N and the 

approximate longitude is 114° 3 7' 13" W. The site is located within the Fort 

Yuma Indian Reservation occupied by the Quechan Indian Tribe. As discussed 

in detail in Section 1.1, the Quechan Tribal Council has the authority to regulate 

the Tribal environment and this FCPCMP will be subject to their review and input 

with final approval made by the USEPA Region 9 with the Quechan Tribal 

Council's concurrence. 

Access to the landfill is off Picacho Road as shown on Figure 1. Vehicles travel 

along Picacho Road, a two-lane, gravel roadway, and then turn into the landfill 

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entrance located on the site's western boundary. This road provides access to 

the pesticide container disposal area located in the northern area of the site. 

1.3 CLOSURE DATE 

The disposal area footprint was delineated recently through trenchings and 

ground surveys and is approximately 12.5 acres as shown on Figure 5. The 

engineering design plans presented in this FCPCMP reflect this 12.5-acre 

footprint area. 

The remaining site capacity is based on the difference between the existing 

topography and the final disposal area contours. Table 1 presents information 

regarding gross air space, final, intermediate and daily cover requirements and 

remaining refuse capacity. The remaining refuse capacity at the site as of January 

2009 is estimated to be approximately 2,059 cy (based on a refuse to soil 

volume ratio of 5:1 and an in-place refuse density of 0.5 tons/cy). It should be 

noted that the current remaining site capacity included in this document reflects 

the maximum utilization of the 12.5-acre refuse area footprint. 

With the total remaining refuse volume for the site at approximately 2,059 cy 

(see Appendix A) and an annual average inflow rate of 1, 7 43 cubic yards per 

year, the landfill's service life is estimated to be approximately 1.2 years (see 

Table 1) from January 2009. 

1.4 SURROUNDING LAND USE 

PCFS FCPCMP 

Adjacent zoning and surrounding land use is compatible with the landfill 

operations. Land use within a one-mile radius of the site is located within the 

Fort Yuma Indian Reservation, which is designated as open space (S) for 

purposes of county zoning, and there are no structures located within 1,000 feet 

of the PCFS. However, this land is not subject to county zoning requirements or 

designations; the land is under the authority of the Quechan Tribal Council. 

There are currently no zoning ordinances within the Tribal land. 

No known inconsistencies or incompatibilities exist with the surrounding land 

uses and no potential adverse land use impacts are foreseeable due to continued 

operation and eventual closure of the landfill. 

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1.5 POST-CLOSURE SITE USE 

PCFS FCPCMP 

The currently proposed post-closure use of the PCFS will be non-irrigated open 

space. No known inconsistencies or incompatibilities exist with the surrounding 

land uses as there are no zoning ordinances set forth by the Quechan Tribal 

Council within or surrounding the PCFS area. Additionally, no potential adverse 

land use impacts are foreseeable due to continued operation and eventual 

closure of the landfill. 

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SECTION 2.0 

EXISTING ENVIRONMENTAL CONTROL 

AND MONITORING SYSTEMS 

BRYAN A. STIRRAT & ASSOCI~TES 
2.0 EXISTING ENVIRONMENTAL CONTROL 

AND MONITORING SYSTEMS 

2.1 LANDFILL GAS CONTROL/MONITORING SYSTEM 

A landfill gas control or monitoring system does not currently exist at the PCFS. 

Previous landfill monitoring utilizing the bar probe method during the regulatory 

agency inspections have indicated no gas migration or surface emission problems. 

In addition, due to the sites remote location, landfill gas migration would not 

create a hazard or nuisance to the public. It should also be noted that the landfill's 

total refuse capacity of 645,333 cy is much less than the 2.5 million cubic meter 

threshold, which triggers the applicability of 40 CFR part 60, Subpart WWW. 

Therefore, no landfill gas collection and control system is required at the PCFS. 

The CIDPW has implemented a Solid Waste Gas Sampling and Reporting Program, 

which includes quarterly surface monitoring at the perimeter of the landfill. The 

last eight quarters of methane gas detection monitoring results are included in 

Appendix H. 

2.2 GROUNDWATER MONITORING SYSTEM 

PCFS FCPCMP 

Initially, because California is an EPA-approved State regulating solid waste 

facilities within the State, the site was thought to fall under the jurisdiction of the 

California Regional Water Quality Control Board - Colorado River Basin Region, 

and site monitoring was performed in accordance with site-specific Waste 

Discharge Requirement No. 88-005, and the more recent blanket Waste 

Discharge Requirements No. 93-071, established for all active landfills within the 

Colorado River Basin Region and prepared to comply with federal regulations. 

As a result, the groundwater monitoring wells have been monitored by the 

County on a semi-annual basis beginning in November 1994 in accordance with 

these WDRs. Accordingly, the semiannual detection monitoring program 

complies with EPA regulation 40 CFR 258.54(a) to include the constituents listed 

in Appendix I, with the exception of the 15 heavy metals, which are included in 

the sampling program every 5 years. 

The existing groundwater monitoring system at the PCFS consists of three 

monitoring wells (P-MW-1, 2, and 4) and one water level measuring station (P-DW3A). Although the groundwater gradient is nearly flat, typically well P-MW-1 is 

located upgradient of the landfill, well P-MW-4 is located down-gradient of the 

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PCFS FCPCMP 

landfill's pesticide disposal area, and wells P-MW-2 and P-DW-3A are located 

downgradient of the landfill. A proposed well (P-MW-5) is anticipated to be 

located cross-gradient of the landfill on the east side of the site. The locations of 

the existing wells and proposed well P-MW-5 are shown on Figure 2. All of the 

existing groundwater monitoring wells were installed by ENVIRON in August, 

1994 and were constructed of two-inch diameter PVC casing with fifteen feet of 

screen. All of the existing wells are secured at the surface with a locking steel 

protective cover set in concrete and a padlock. Well construction logs are 

included in Appendix B. 

Monitoring wells (P-MW-1, P-MW-2, P-MW-4) are sampled semi-annually in 

accordance with the Sampling and Analysis Plan (included in Appendix C) using 

dedicated bailers. The Sampling and Analysis Plan complies with 40 CFR 258.53. 

Protocols for proposed monitoring well P-MW-5 are anticipated to follow the same 

sampling and analysis plan as established for the existing monitoring wells. 

As discussed in Section 1.1, GLA has prepared a SSFR to modify the list of 

detection monitoring parameters provided in 40 CFR 258.54{a)(1) and {2). This 

SSFR is included in Appendix C-1. 

Groundwater samples are analyzed for the Appendix I list of volatile organic 

compounds {VOCs) provided in 40 CFR, Part 258, arsenic (since it is potentially 

associated with some pesticides) and the metal surrogates (chloride, nitrate as 

nitrogen, sulfate, and total dissolved solids). In addition, field parameters (pH, 

dissolved oxygen, electrical conductivity, turbidity, and temperature) are also 

measured during sampling. Every five years, the groundwater monitoring wells are 

analyzed for the full suite of constituents of concern (COCs) listed in Appendix II 

of 40 CFR, Part 258. COC sampling was last performed at the PCFS in August 

2006, and is scheduled for sampling during the Winter/Spring 2011 monitoring 

event. In addition, following construction of proposed well P-MW-5, samples from 

this well will be analyzed for the entire 40 CFR 258 Appendix I list of parameters 

(including the metals) for at least two semiannual monitoring events. 

During each semi-annual monitoring period, the surface monuments and well 

casings are inspected for security and damage. Any problems with the wells that 

are reported on the field data sheets are relayed to the CIDPW. If significant 

damage to a well is observed, then the CIDPW will initiate a maintenance 

program to address the problem. 

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2.3 LEACHATE COLLECTION AND REMOVAL SYSTEM/MONITORING 

The PCFS is unlined and predates the requirements to install a leachate collection 

and removal system (LCRS). Therefore, LCRS monitoring is not performed at the 

site. To date, no leachate seeps have been observed at the landfill. 

2.4 STORMWATER MONITORING 

PCFS FCPCMP 

As authorized by the Clean Water Act, the National Pollutant Discharge 

Elimination System (NPDES) permit program controls water pollution by 

regulating point sources that discharge pollutants into waters of the United 

States. The CIDPW is currently working on submitting a Notice of Intent (NOI) 

under the Multi-Sector General Permit and developing a Stormwater Pollution 

Prevention Plan (SWPPP) and Stormwater Monitoring Plan (SWMP) for the PCFS. 

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SECTION 3.0 

CLOSURE PLAN 

BRYAN A. STIRRAT & ASSOCIATES 
3.0 CLOSURE PLAN 

3.1 INTRODUCTION 

Closure of the PCFS will be performed in accordance with applicable regulatory 

standards included in 40 CFR, Part 258, Subpart F. In some cases, the California 

standards, which are being adhered to, are more stringent than the Federal 

regulations. 

The costs associated with closure of the PCFS are described in Section 7.0 of this 

document. The components and systems required for closure of the PCFS 

include: the final grading plan and final cover design, surface water drainage and 

erosion control systems, landfill gas monitoring system, groundwater monitoring 

system and site security. A description of these closure components as well as a 

schedule for construction of the PCFS closure improvements is presented in the 

following subsections. 

3.2 FINAL GRADING 

PCFS FCPCMP 

This section describes the final grading plan proposed for the PCFS. The most 

current topographic map (dated June 12, 2006} has been used as the base map 

for the final grading plan (Figure 5}. 

Upon cessation of refuse disposal operations, the deck area will be set at a 

gradient of three percent to facilitate drainage and accommodate for future 

differential settlement of the underlying waste. The proposed drainage control 

system provides for the handling of on-site surface flows as well as the diversion 

of potential run-on from surrounding areas. The drainage control system consists 

of drainage berms and concrete and asphaltic concrete (AC} V-channels. Due to 

the relatively shallow nature and age of the refuse prism at this site, settlement 

related drainage problems on the deck areas are not anticipated, as discussed in 

Section 3.4.1. The final cover described in Section 3.3.2 (see Figure 6} will then 

be placed over the refuse prism areas. Final slopes of the PCFS will be at 

maximum grades of 2.25:1 (horizontal to vertical) (Figure 5}. The final grades 

have been designed to blend with the natural topography of the surrounding 

area. 

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3.3 FINAL COVER 

The purpose of a final cover is to provide an effective barrier to infiltration of 

surface water and to encapsulate wastes, which reduces the potential for vectors, 

odors, and gas emissions. The cover also provides a base for vegetation, which 

has been documented to reduce drainage velocities, erosion and infiltration. 

3.3.1 MINIMUM DESIGN STANDARDS 

PCFS FCPCMP 

The minimum final cover standards for the PCFS are outlined in the closure and 

post-closure requirements for MSW landfills contained in 40 CFR, Part 258, 

Subpart F, Section 258.60. The Federal regulations require the following: 

• A cover with a permeability less than or equal to the hydraulic conductivity of 

any bottom liner system or natural sub-soils present, or a permeability no 

greater than 1 x1 o-s em/sec, whichever is less. 

• A cover that minimizes infiltration through a closed landfill by the use of an 

infiltration layer that consists of a minimum 18 inches of earthen material. 

• A cover which minimizes erosion of the final cover by the use of an erosion 

resistant layer that contains a minimum six inches of earthen material that is 

capable of sustaining native plant growth. 

However, under 40 CFR 258.60 (b), an alternative final cover system design may 

be approved if it is demonstrated that the alternative final cover achieves 

equivalent reduction in infiltration to the prescriptive standard, and that the 

proposed erosion layer provides equivalent protection from wind and water 

erosion as the specified prescriptive standard. 

In addition, the final cover should be designed for minimum maintenance 

requirements. Grading shall be designed to prevent ponding, provide for slopes 

of at least three percent (a lesser slope may be allowed if surface drainage is 

diverted) and minimize surface erosion by water and wind in areas of greater 

than ten percent slope and in surface drainage courses. 

It should be noted that LEACHM modeling results presented in.a SSFR for the 

proposed alternative final cover, demonstrates that the proposed alternative final 

cover provides equivalent protection in infiltration to the prescriptive standard 

has been prepared. It is being concurrently submitted to the EPA for review and 

approval as discussed in Section 1 .1. 

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3.3.2 FINAL COVER DESIGN 

Several factors were taken into consideration in determining the cover design for 

the site to provide for adequate performance of the cover. These included the 

geometry of the existing landfill, climatic conditions, potential settlement, 

available cover materials, erosion protection, vegetative growth and end use at 

closure. It was determined that an alternative final cover design utilizing a 

monolithic engineered select soil cover is the most appropriate cover system for 

the PCFS based on these parameters. 

An engineering analysis (see Appendix D-1) concluded that the site-specific 

climatological and soil conditions support the use of the proposed alternative 

final cover design utilizing a monolithic engineered soil. This design will meet or 

exceed the prescribed performance criteria and will be more economical for site 

closure than prescriptive standards. 

Based on the analysis of the SSFR in Appendix D-1, an alternative final cover 

design utilizing a monolithic cover is proposed, consisting of the following: 

• A four and a half foot thick monolithic cover layer composed of on-site or 

near-site soils , which includes a minimum one foot of which has been 

determined to be in-place (by the recent existing cover evaluation). 

• An admixture of pit run rock (clasts greater than six inches will not be used) 

and soil will be placed in the upper six to eight inches of the final cover to 

provide protection against wind and water erosion. 

• A minimum of two percent native plant community to be maintained to 

provide reasonable performance for the ET monolithic alternative cover 

system. 

Because the analysis performed to date indicates that a four and a half foot thick 

final cover section composed of on-site or near-site soil material will meet or 

exceed the performance criteria of the prescribed standard, a traditional barrier 

layer is not proposed for the alternative final cover design. A typical crosssection of the proposed alternative final cover system is shown on Figure 6. 

The alternative final cover configuration has been designed to: 

• Ensure the containment of waste materials; 

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• Minimize the infiltration of water from rain and provide a vegetative cover of 

native shrubs and grasses; 

• Prevent exposure of people and animals to waste; 

• Limit landfill gas emissions; 

• Minimize odor; 

• Control fires; and 

• Provide for an aesthetically pleasing appearance. 

The soil characteristics of the site material were identified and evaluated for the 

PCFS (see Appendix D-1 ). This work included laboratory testing of two soil 

samples from the on-site borrow sources and infiltration modeling. Based on the 

findings of the evaluation, on-site materials meet the permeability equivalence 

requirements for final cover. Colorado River Basin Regional Water Quality 

Control Board (RWQCB), USEPA, and the Quechan Tribal Council approval of 

this design will be sought prior to implementation of this alternative final cover 

system. 

3.3.3 FINAL COVER CONSTRUCTION 

PCFS FCPCMP 

Clearing and Grubbing 

Prior to final grading and placement of the cover, the deck and slope of the 

landfill will have all existing vegetative materials removed from the foundation 

surface without disturbing the underlying refuse. All materials generated by the 

clearing and grubbing operation shall be buried on the upper deck and covered 

with one foot of select soils from an on-site source. 

Foundation Layer 

Foundation layer material will be added in areas of the refuse prism which are 

covered with less than the two-foot minimum of interim cover material. It is 

assumed that the majority of the site has an existing one-foot thick interim cover 

in-place. The thickness of interim cover will be verified by pot-holing and 

additional foundation material placed to meet minimum thickness requirements 

and to achieve positive gradients for adequate surface water drainage. The 

entire thickness of the foundation layer will be required to meet 90 percent 

relative compaction according to ASTM 01557. 

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PCFS FCPCMP 

Monolithic Select Soil Layer 

The proposed monolithic layer will be constructed with select soils obtained from 

an on-site or near-site source(s), and with the exception of the erosion control 

layer, the monolithic soil layer will exhibit a grain size distribution that excludes 

particles in excess of three inches and includes a minimum fines content of seven 

percent for an individual test and eight percent for the average of ten 

consecutive tests. Prior to placement, these materials will be wetted to optimum 

moisture and thoroughly mixed to obtain a near uniform condition. The material 

will then be placed in lifts with a maximum uncompacted thickness of six to eight 

inches. Each lift will be spread evenly and compacted to a minimum of 90 

percent of maximum density. 

Where quality control tests indicate that the moisture content, density, 

permeability or grain size distribution of any lift, or portion thereof, does not 

meet the specifications in Appendix 1 of Appendix D, that particular portion shall 

be retested, and if necessary reworked until the specified moisture, density, and 

permeability has been attained. Special attention will be given to unsaturated 

material characteristics to verify that they satisfy the requirements specified in 

Appendix 1 of Appendix D. No additional material will be placed over an area 

until the previously placed material has been tested and found to meet the 

design specifications. Testing of the materials will be done in accordance with 

the CQA Plan included in Appendix 1 of Appendix D. 

Erosion Resistant Layer 

A minimum plant coverage of two to five percent will provide reasonable 

performance for the proposed alternative cover. Vegetation for the proposed 

alternative cover will consist of native plant species. 

An admixture of pit run rock (clasts smaller than six inches) and soil will be placed in 

the upper six to eight inches of the monolithic cover layer to provide additional 

protection of the final cover system against wind and water erosion. The pit run rock 

and soil will be obtained from local sources. 

See the Alternative Final Cover SSFR (Appendix D-1) for a detailed analysis of the 

erosion resistant layer. 

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3.3.3.1 ACCESS ROAD 

Access to the deck area of the PCFS will be provided by an access road. The 

access road will provide vehicular access to the deck in order to perform postclosure maintenance and monitoring of the final cover and drainage facilities. 

3.4 LANDFILL SETTLEMENT 

3.4.1 SEITLEMENT ANALYSIS 

PCFS FCPCMP 

This section describes the method of settlement analysis used to evaluate the total 

potential settlement that may occur during the post-closure period. There are 

three principal modes of settlement for a typical municipal waste landfill. These 

can be described as: consolidation induced settlement resulting from the loss of 

fluids through drainage, dewatering by absorption, or release of leachate; 

shrinkage related settlement occurring as a result of overall volume loss due to 

microbial conversion of solids and liquids to carbon dioxide and methane gas; 

and compaction related settlement resulting from the reorientation of solids into a 

more dense configuration (Huitric, 1981 ). In addition to these "classic" settlement 

modes, dynamic settlement can occur during and shortly after earthquake events 

when soil and/or refuse particles consolidate as a result of ground shaking. 

While it is theoretically possible to calculate the expected settlement from each 

of the phenomena described above, the data available for the PCFS and, in fact, 

virtually all landfills are insufficient to make a site-specific analysis. Therefore, the 

analysis for the PCFS is based on historical settlement. 

Studies performed by Hagerty, Pavoni and Hur (1973) and the Los Angeles 

County Sanitation Districts (Huitric, 1981) for landfills in the Southern California 

area indicate that landfill settlements are typically between two and 40 percent 

of original refuse thickness. The following analysis assumed a 20 percent total 

settlement occurring logarithmically over an approximately 30-year period. 

Given the extremely dry climate at the landfill, these assumptions are considered 

conservative. 

The first step in the analysis of settlement at this site involved an evaluation of the 

total anticipated depth of refuse at closure. Several points on the site were taken 

and a vertical refuse placement history estimated by taking the total depth of 

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3.4.1.1 

refuse disposed. For example the deepest point of waste is estimated at 50 feet. 

A relatively uniform refuse placement rate over the life of the site was then 

assumed. 

The theoretical settlement, which has already occurred at a given node in the 

refuse prism, was subtracted from the total anticipated for that node to generate 

an estimate of the remaining settlement potential. For example, the deepest 

point of waste will experience approximately 1 0 feet of settlement (20% of 50 

feet) over a 30 year period. Because the landfill has been in operation since 

1977, the analysis assumes that 50% of the settlement will have already occurred 

at closure and approximately 5 feet of settlement during the post-closure period 

has been calculated at the deepest point of waste. 

SETILEMENT DUE TO UNDERLYING NATIVE MATERIAL SUBSIDENCE 

The potential for settlement due to subsidence of the underlying natural geologic 

materials at the PCFS was also evaluated. However, given that the in-place 

density of the refuse at the site was estimated to be less than that of the natural 

soil excavated from the fill area, and considering that the depth of refuse at the 

site is shallow, settlement due to subsidence of the underlying natural geologic 

materials is not anticipated. 

3.5 CLOSED LANDFILL STABILITY 

PCFS FCPCMP 

In accordance with 40 CFR, Part 258, Subpart F, precautions should be taken to 

maintain the integrity and effectiveness of the final cover. Accordingly, landfill 

cover stability for the PCFS was analyzed. 

The project plans prepared by BAS (12/2007) were analyzed by Geologic 

Associates for the proposed closure/post-closure plan. Consistent with the plan, 

the site is proposed to have a 4-1/2 foot thick soil final cover over the refuse 

mass (BAS, 2007) consistent with the Final Closure/Post-Closure Maintenance 

Plan (FCPCMP) for the Landfill. The results of these analyses are provided later in 

this section. 

The soil materials at the site include municipal solid waste (MSW) fill below 

proposed compacted cover/fill materials. No liners or geotextiles are proposed 

for the cover in the closure plan. 

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PCFS FCPCMP 

Geotechnical parameters required for analysis include unit weight and shear 

strength parameters (angle of friction and cohesion). For the compacted cover 

soils, which are predominantly cohesionless in nature, the angle of friction and 

unit weight were based on average values obtained from laboratory testing of 

the borrow soils. Three samples (B-1, B-2, and B-3) were obtained from the 

borrow area south of the existing landfill (in the approximate location presented 

in Figure 1.1 in Appendix I) and transported to our laboratory for geotechnical 

testing. The samples were tested for gradation analysis (ASTM 0422), maximum 

density (ASTM 01557), and direct shear testing (ASTM 03080). The samples 

tested for direct shear were remolded in the laboratory to 90% of the soil 

maximum dry density near optimum moisture content. The results of the direct 

shear testing are presented in Appendix I and summarized below. Parameters 

for the refuse or municipal solid waste (MSW) are based on industry-wide typical 

values from previously published information (Singh and Murphy, 1990). A 

summary of the parameters used in the slope stability analyses is presented 

below. 

Geotechnical Materials Strenl th Parameters 

Material Unit Weight Friction Angle Cohesion 

(pcf) (degrees) (psf) 

Compacted Cover/Fill Soils 118 30 125 

Refuse (MSW) 80 30 200 

Conventional static and pseudo-static stability analyses for fill slopes were 

performed using the SLOPE/W (GeoStudio, 2007) computer program. Analytical 

methods used for analysis included the Morgenstern-Price method for circular 

failure modes. The program calculates the factor-of-safety for a user-specified 

geometry using a number of analytical methods for limit equilibrium. 

The cover soils were modeled using a representative cross section constructed 

along the western end of the landfill in the area of the maximum slope height (25 

feet) above the proposed adjacent basin. The cover sols were modeled with a 

thickness of 4-1/2 feet above the existing refuse with a slope inclination of 2.25:1 

(horizontal to vertical). 

Stability calculations were performed to evaluate the static and dynamic stability 

of the final (post-closure) configuration of the cover. Refuse prism 

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PCFS FCPCMP 

configurations, past landfill history, and proposed closure plans were provided by 

BAS. 

Based on the above material parameters, the cross section was analyzed for 

static slope stability. Groundwater is assumed to be below the base of the refuse 

and thus, is not significant in this analysis. The results of the static slope stability 

run is presented in Figure 1.2 in Appendix I and is summarized in the following 

Table. 

Static Slope Stability Analysis 

Description of Analysis Factor of Safety 

Static Slope Stability Analysis 2.1 

The static cover stability for the maximum height cross section indicates a 

minimum factor of safety of 2.1 (which is well above the minimum required static 

factor of safety of 1.5). 

CCR Title 27 requires the cover slope stability under pseudo-static (dynamic) 

conditions demonstrate a factor of safety greater than 1.5 under the Maximum 

Probable Earthquake (MPE) for Class Ill facilities. Accordingly, a seismic hazard 

assessment was performed for the facility to determine the MPE event for the 

site. The site acceleration was calculated by performing a deterministic seismic 

hazard analysis using the Maximum Probable Earthquake (MPE) on the closest 

active to the site. This analysis was performed using the computer program 

EQFAULT (Blake, 2000a) presented in Appendix I. The results of this analysis 

indicate a site horizontal acceleration of 0.09g from the design earthquake on 

the Imperial Fault located approximately 40 miles from the site. In addition, 

historic earthquakes were searched using the computer program EQSEARCH 

(Blake, 2000b) to insure that there were no possible historic earthquakes greater 

than the deterministic deign earthquake. Review of the database indicates that 

the 1852 earthquake with a magnitude of 6.3 at a distance of 26.6 miles from 

the site has a calculated site acceleration of 0.11 g. Accordingly, our design site 

acceleration is 0.11 g for this analysis. 

The pseudo-static stability of the cover is below the required stability of 1.5 

Therefore, for the proposed closure project, seismic-induced permanent 

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displacements due to the MPE were estimated using procedures described by 

Bray et. al., (1998) and Bray and Rathje (1998). The procedure is based on the 

methods described by Newmark (1965) for determining displacement of a rigid 

block resting on a sliding plane subjected to earthquake-type motions. The 

procedure is based on the premise that the sliding block will undergo 

displacement only during the periods when the maximum ground acceleration 

(kmax) exceeds the yield acceleration (ky) for the sliding block, (i.e. displacements 

occur when kv is greater than kmaJ The representative cross section was 

analyzed to determine the yield acceleration (ky) to achieve a pseudo-static factor 

of safety equal to 1.0. The results are presented in Figure L.3 in Appendix I and 

indicate a yield acceleration of 0.39g. Accordingly, since the calculated 

horizontal site acceleration due to the MPE event (0.11 g) is significantly less than 

the yield acceleration (0.39g) to initiate any displacement, the calculated 

permanent seismic displacement due to the design earthquake event is 

negligible. 

3.6 CONSTRUCTION QUALITY ASSURANCE 

PCFS FCPCMP 

The construction of the final cover system shall be carried out in accordance with 

a CQA plan certified by an appropriately registered engineer or a certified 

engineering geologist. The CQA plan will provide evidence that suitable 

materials and standard construction practices are used to place the final cover 

system and to document that placement is consistent with the closure plan 

design specifications. Elements of the CQA Plan include: project description 

and definitions, qualifications and responsibilities, requirements for the final cover 

evaluation, inspection standards, testing frequencies, monitoring procedures, and 

documentation. The CQA plan is included in Appendix 1 of Appendix D. It 

should be noted that the CQA Plan addresses all of the general guidelines in the 

Interstate Technology and Regulatory Council (ITRC) 2003 guidance document. 

The CQA Plan has been developed to describe the methods and procedures to 

be used to install the final cover as specified in 40 CFR 258.60. 

A final CQA Plan will be developed once the final cover design has been 

approved. The final CQA Plan will provide a detailed methodology for 

determining for determining existing cover soil thickness, processing these 

materials, integrating the final cover soils into the final cover, and the CQA 

testing required to demonstrate that appropriate material types and construction 

practices were used. 

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3.7 DRAINAGE AND EROSION CONTROL 

3.7.1 DRAINAGE DESIGN 

3.7.1.1 

3.7.1.2 

PCFS FCPCMP 

The primary functions of the PCFS drainage control system is to collect and 

convey stormwater in a controlled manner to minimize erosion of the final cover 

and inhibit infiltration of stormwater into the refuse prism in order to maintain the 

integrity and effectiveness of the final cover in accordance with 40 CFR 258. The 

final surface or deck area of the landfill will be sloped to prevent ponding and 

promote lateral runoff of stormwater, which falls directly on the landfill. The 

following sections describe the existing drainage control features and the 

proposed drainage design for closure of the PCFS. 

SURFACE WATER HYDROLOGY 

A hydrology study for proposed conditions at the site was conducted based on a 

designed 1 00-year/24-hour storm, which is more conservative than the Federal 

regulations for a 25-year/24-hour storm. The objective of the hydrology study 

was to calculate stormwater run-off for sizing and location information for the 

site's storm drain facilities at closure. 

The Rational Method was used for the calculation of the peak discharge of a 24-

hour, 1 00-year storm event. Estimated runoff values were calculated based on 

the National Oceanic and Atmospheric Administration Atlas PrecipitationFrequency Maps. A computer program developed by Advanced Engineering 

Software was used to compute the run-off. The hydrology study map for on-site 

flows and a summary of the peak discharge rates is shown on Figure 8. The 

Hydrology Study calculations are presented in Appendix E. 

EXISTING DRAINAGE SYSTEM 

There are no improved drainage facilities currently existing on the site. Surface 

water flows follow existing natural contours in several directions and finally 

discharge into a major natural drainage course, which flows in a southeasterly 

direction. 

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3.7.1.3 PROPOSED FINAL DRAINAGE CONTROL SYSTEM 

The final drainage design is shown on Figure 5. Top deck earthen berms, which 

will contain an admixture of pit run rock and soil in the upper six to eight inches 

for erosion protection, shall be constructed to direct run-off away from the slope 

area. Collected run-off from the deck area will be directed into two discharge 

points located at the south and southwest portions of the landfill and into two 

proposed basins. This discharge point shall be protected with a concrete Vchannel and energy dissipating structure to minimize erosion. All run-off from 

the site will be intercepted by an asphaltic concrete (AC) V-channel and directed 

to the proposed basin on the southwest side of the site. Infiltration rates for arid 

areas are extremely high and any stormwater, which falls directly into the pits, 

will be negligible and will evaporate or infiltrate into the ground rapidly. The 

sizing of the concrete and AC V-channels are presented in Appendix E. 

3.7.2 SOIL LOSS ANALYSIS 

PCFS FCPCMP 

The Revised Universal Soil Loss Equation (RUSLE) was used to evaluate potential 

soil losses within the watershed boundary of the PCFS site. The RUSLE, 

developed by the U.S. Department of Agriculture, considers soil and vegetation 

type as well as physical and climatic features of the landfill area. 

The RUSLE is: 

where 

A 

A 

R 

K 

L 

s 

c 

p 

= 

= 

RKLSCP 

average annual soil loss, in tons/acre/year 

rainfall and runoff erosivity index 

soil erodibility factor, tons/acre 

slope-length factor 

slope-steepness factor 

cover-management factor 

practice factor 

The soil loss analysis performed is based on a "closed landfill" condition. At 

closure, the potential soil loss is minimal since the landfill will have a compacted 

final cover with six to eight inches of a pit run rock and soil admixture, 

vegetation, and a storm drain system installed which all contribute to controlling 

soil erosion. 

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The following RUSLE constants were utilized: 

R = 27.0 

K = 0.06 

0.4:SLS:S9.5 

c = 0.05 

p = 1.0 

Located in a Type II area 

Based on 25-50 percent gravel 

Dependent upon length gradient 

Based on a monolithic cover with gravel admixture 

Practice factor 

For the purpose of the soil loss analysis, the landfill was divided into regions 

based upon the average slopes of the final grades and surface drainage. The 

landfill soil loss analysis data is presented in Appendix F. The average soil loss for 

the PCFS is 0.23 tons/acre/year, which is within the two tons/acre/year 

recommended by the USEPA. Over the 30-year post-closure maintenance 

period, the average soil loss over the entire site would be 0.04 inches. 

The top layer of the final cover will include a two and a half foot thick layer of onsite or near-site soil material that will comprise the monolithic vegetative cover 

layer. In addition, the top six to eight inches of this layer will include an 

admixture of pit run rock and soil. According to the Wind Erodibility Index from 

the USDA, the (I) value for WEZ equation is approximately zero (0) for soils not 

susceptible to wind erosion or saltation due to coarse fragments at the surface or 

wetness. Therefore, the annual soil loss due to wind erosion is small due to the 

coarse soil used. When combined with the soil loss to surface water runoff, the 

annual soil loss is still less than two tons/acre/year and is therefore adequate for 

average annual soil loss. 

3.7.3 EROSION CONTROL 

PCFS FCPCMP 

The landfill closure design has two primary erosion control features that will 

reduce the potential for soil erosion due to water and wind. These features 

include fill area grading and the monolithic vegetative cover, which will include a 

mixture of select soils and pit run rock. The decks will be graded for sheet flow 

runoff with a minimum slope of approximately three percent. Any large erosion 

gullies formed during storm events on the deck and slopes will be promptly filled, 

and track walked by a crawler tractor to recompact the soil. 

In addition to pit run rocks, protection of the final cover soils will be provided 

through the placement of non-irrigated, native plant species cover serving as a 

short term and long term erosion control cover. Approximately two percent of 

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vegetation needs to be sustained because that is the percentage of natural 

vegetation that is typical in the vicinity of this site. The final cover seed mixture is 

identified in Table 2. All final cover slope and deck areas will be seeded with this 

mixture. The plants were selected because of their adaptability to the landfill's 

general climatic area; reseeding potential; and required root depth of less than 

30 inches. The long term vegetative maintenance needs are anticipated to be 

minimum since the plants are tolerant to disease, fire and insects. The plants are 

also compatible with the off-site native plant community and will provide a similar 

appearance to the surrounding native open space vegetation. 

It is proposed that the final cover be seeded in December, prior to the "wet" 

season. Seeding will be accomplished by drill seeding. Prior to drill seeding soil 

preparation/fertilization is performed by spreading the appropriate amendments. 

The drill seeder is equipped with seed boxes calibrated for the specified seed 

types, soil discs and a metal or wood rake. As the discs till the soil to a onequarter inch depth, the seed boxes drop the seed directly into the soil. The rake 

then passes over the loosened soil, which buries the seed. For best soil 

preparation and drill seeding results the soils should be moistened to a 2-inch 

depth. 

3.8 LANDFILL GAS CONTROL/MIGRATION MONITORING SYSTEM 

PCFS FCPCMP 

In order to ensure detection of potential gas migration throughout post-closure, a 

landfill gas migration monitoring system is proposed for the site. The proposed 

landfill gas migration monitoring probe plan (Appendix J) has incorporated 

elements from 27 CCR, Section 20925, which is more stringent than the Code of 

Federal Regulations. There are currently no structures located within 1,000 feet 

of the PCFS. Four proposed gas migration monitoring well locations, with 

varying depths, will be spaced no more than 1,000 feet apart. 

Based on the depth of waste, it has been determined that monitoring wells will 

have one to three probe depths installed within each monitoring well. The wells 

will be constructed to provide a minimum seal of five feet of bentonite at the 

surface and between the monitored zones. In addition, each individual probe 

(i.e., shallow, intermediate, deep) will be clearly marked with the letters "S" for 

shallow probe or "I" for intermediate probe or "D" for deep probe to delineate 

depth. A typical subsurface monitoring well (probe) is shown on Figure 6. 

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The landfill gas migration monitoring wells will be installed by a licensed drilling 

contractor under the direction of a design engineer or engineering geologist. 

The wells shall be logged during installation by a geologist or geotechnical 

engineer. A final report will be prepared incorporating as-built surveyed probes 

locations, field logs, and daily reports. 

As presented in Section 2.1 of this document, a landfill gas control system is not 

necessary for this site. 

3.9 GROUNDWATER MONITORING SYSTEM 

As previously discussed in Section 2.2, the existing groundwater monitoring 

system consists of one upgradient and three downgradient monitoring wells. 

Based on historical water elevation data, generally, well P-MW-1 is located 

upgradient of the landfill; well P-MW-4 is located downgradient of the landfill's 

pesticide disposal area; wells P-MW-2 and P-DW-3A are located downgradient of 

the landfill. With the exception of well P-DW-3A, which is used as a water level 

measuring station, these wells are currently being monitored and/or sampled on 

a semi-annual basis in accordance with the groundwater sampling and analysis 

plan included in Appendix C. A proposed groundwater monitoring well (P-MW5) is anticipated to be located cross-gradient of the landfill. Protocols for 

sampling proposed monitoring well P-MW-5 are anticipated to follow the same 

sampling and analysis plan as the existing monitoring wells. 

As discussed in Section 1.1, GLA has prepared a SSFR to modify the list of 

detection monitoring parameters provided in 40 CFR 258.54(a) (1) and (2). This 

SSFR is included in Appendix C-1. 

3.10 LEACHATE COLLECTION AND REMOVAL SYSTEM 

PCFS FCPCMP 

The PCFS is unlined and predates the requirements for installation of a liner and 

LCRS. Additionally, operators of existing MSWLF units are exempt from Subpart 

D (i.e., 258.40) of 40 CFR under certain conditions. Section 258.1 (f)(1) allows 

for existing MSWLF units to be exempt from Subpart D, so long as the operator 

is able to demonstrate that the existing MSWLF unit accepts less than twenty 

(20) tons of MSW daily, based on an annual average, and there is no evidence of 

groundwater contamination from the MSWLF unit. CIDPW records indicated 

that the PCFS received an average of 13 tons per day in 2008 and routine 

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groundwater monitoring to detect contaminants is performed according to the 

schedule in Appendix C. Therefore, the PCFS is exempt from the requirements 

of Subpart D for installation of a liner and a LCRS. 

3.11 SITE SECURITY 

In accordance with 27 CCR, Section 21135, signs will be posted at all points of 

access to the PCFS 60 days prior to the last receipt of waste at the site and for a 

period not less than 180 days after the facility has received the final shipment of 

waste. Signs will state the intended date of last receipt, the location of 

alternative solid waste management facilities, and a number to call in cases of 

emergency. A notice shall be placed in a local newspaper(s) 30 days prior to the 

last receipt of waste, which also includes the intended date of the last receipt of 

waste at the site and the location of alternative solid waste management 

facilities. 

In addition, the operator is required to secure all points of access with a lock and 

gate and place signs at all access points prohibiting unauthorized entry. These 

measures are intended to reduce incidents of vandalism and illegal disposal of 

wastes during the post-closure maintenance period. 

In accordance with 27 CCR, Section 21135, all points of access to the site will be 

restricted as of the date of the final shipment of waste. A sign similar to that 

presented in Figure 9 will be posted at the entrance to the PCFS. 

Site security at the PCFS is currently provided by a locking gate and chain-link 

fence around three sides of the site (north, south and west sides). For the 

location of the existing perimeter fence and gate, see Figure 2. Additional 

fencing is proposed to be placed along the entire landfill perimeter in order to 

prevent unauthorized entry to the site at closure. 

3.12 STRUCTURE REMOVAL/DECOMMISSIONING OF ENVIRONMENTAL 

CONTROL SYSTEMS 

PCFS FCPCMP 

Site structures not deemed essential for closure construction or post-closure 

maintenance will be dismantled and removed. There are currently no permanent 

structures located at the PCFS and no structures will remain on-site during the 

post-closure maintenance period. 

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3.13 

3.13.1 

PCFS FCPCMP 

At this time there are no plans to decommission any of the environmental 

control systems at the site during the closure period. If deemed necessary, any 

groundwater monitoring wells that will not be utilized for monitoring purposes 

during the post-closure period, or that require replacement during ongoing 

operations, will be abandoned as approved by the appropriate agencies and in 

accordance with the Imperial County Building Inspection regulations and the 

Department of Water Resources Bulletin 7 4-90. 

CLOSURE IMPLEMENTATION SCHEDULE 

CLOSURE PROCESS 

After approval of the Closure Plan, construction plans and specifications will be 

prepared by the operator and submitted to the Quechan Tribal Council with final 

regulatory approval made by the USEPA Region 9. It should be noted that EPA 

approval is required for any variance from the prescriptive standards as outlined 

in 40 CFR 258 through the SSFR process. The bidding package will be issued 

and a contractor selected. 

A closure implementation schedule for the PCFS is presented in Table 3, which 

delineates the estimated time frame to complete each closure task described in 

this FCPCMP. This schedule may differ from the selected Contractor's schedule 

based on the Contractor's equipment and personnel resources. 

Closure construction will begin with mobilization of equipment and materials. 

The type of equipment and required personnel expected to be utilized during 

closure construction includes the following: 

• Types of Equipment 

- Dozers 

- Loaders 

- Compactors 

- Trucks 

- Soil Conditioning (Grizzlies) and Screening Equipment 

• Personnel 

- Equipment Operators 

- Surveyors 

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3.13.2 

PCFS FCPCMP 

- Mechanics 

Once equipment is on-site, rough grading can begin. During the preparation of 

the site for final cover placement, additional final cover materials may be 

stockpiled. Necessary borrow material will continue to be transported and 

stockpiled on-site during construction of the final cover, as necessary. Prior to 

placement of final cover, the rough grading and final cover keyway installation 

will be performed which should take approximately one month. 

Placement of the final cover materials will begin after rough grading and drainage 

improvements at the site are complete. It is anticipated that construction of the 

final cover will take approximately one month to complete. The access 

road/staging area construction will be completed in conjunction with the 

completion of the final cover. The gas migration monitoring system installation 

will also take place in conjunction with the completion of the final cover and 

should be completed within 15 days. Upon completion of the gas migration 

monitoring system and access road/staging area the landscaping improvements 

will be performed, which should take approximately one week. Upon 

completion of the tasks described above for closure, demobilization will begin. 

CONSTRUCTION MANAGEMENT 

A construction management team will be on-site during the entire period of 

construction. The team will be under the direction of a construction manager, 

who will be responsible for supervision of construction of the various features 

included in the closure plan. The construction manager will coordinate the 

activities of the on-site contractors and will provide liaison among the design 

engineers and the contractor(s). Other key staff will include a site engineer, who 

is a County staff representative, and construction inspector(s). A survey crew 

and a geotechnical CQA crew will be present, as required. 

Survey Control 

The survey control crew, under the direction of the contractor will be responsible 

for location of the closure plan improvements and for record drawing 

information. They will be responsible for establishing that the various 

components of the cover conform to grade and/or thickness requirements of the 

construction drawings and specifications. 

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PCFS FCPCMP 

CQA for Final Cover Placement 

The construction specifications will include the CQA plan for cover placement. 

A geotechnical CQA crew, under the direction of a Geotechnical Engineer, will 

be on-site full time during the placement of the final cover to monitor 

compliance with cover design and installation methods included in the CQA 

plan. The CQA personnel will have day-to-day responsibility to oversee cover 

placement and to evaluate whether the cover is constructed according to 

specifications. 

As described in Section 3.6, the CQA Plan is included in Appendix 1 of Appendix 

D. It should be noted that the CQA Plan addresses all of the general guidelines 

in the Interstate Technology and Regulatory Council (ITRC) 2003 guidance 

document. The CQA Plan has been developed to describe the methods and 

procedures to be used to install the final cover as specified in 40 CFR 258.60. 

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SECTION 4.0 

POST-CLOSURE MAINTENANCE PLAN 

BRYAN A. STIRRAT & ASSOCIATES 
4.0 POST-CLOSURE MAINTENANCE PLAN 

4.1 INTRODUCTION 

Post-closure maintenance of the closed PCFS will be performed in accordance 

with the applicable regulatory standards presented 40 CFR Section 258.61. Postclosure maintenance activities for the PCFS will consist of: 

• Landfill Gas Migration Control System Monitoring and Maintenance 

• Groundwater/Vadose Zone Monitoring and Maintenance 

• Stormwater Monitoring 

• Final Cover Inspection and Maintenance 

• Settlement Monitoring 

• Vegetative Cover Inspection and Maintenance 

• Access Road Maintenance 

• Drainage Control System Inspection and Maintenance 

• Site Security Inspection and Maintenance 

The following subsections will discuss compliance with 40 CFR 258, as 

applicable. 

Post-closure care requirements will be conducted in accordance with 40 CFR 

258.61. Post-closure care must be conducted for 30 years with the exception 

where the duration may be decreased in accordance with 40 CFR 258.61 (b)(1) 

or increased in accordance with 40 CFR 2 58.61 (b )(2) with approval by the 

USEPA and is deemed a sufficient duration to protect human health and the 

environment. 

4.2 RESPONSIBLE PARTIES 

PCFS FCPCMP 

The following is a listing of the responsible parties who will be involved in postclosure maintenance and monitoring activities at the PCFS. Questions pertaining 

to this Final Post-Closure Maintenance Plan should be directed to the CIDPW 

Project Engineer for the PCFS. 

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Landfill Owner 

Quechan Indian Tribe Council 

P.O. Box 1899 

Yuma, Arizona 85366-1899 

( 602) 5 72-21 02 

Landfill Operator 

County of Imperial 

Department of Public Works 

155 South 11th Street 

El Centro, California 92243 

William Brunet, Director of Public Works 

Frank Fiorenza, Deputy Director of Public Works 

(760) 482-4462 

Prior to any transfer of ownership during the closure or post-closure maintenance 

period, responsible parties shall inform the new owner of current regulations, 

conditions, and agreements assigned to assure compliance. Additionally, the 

responsible parties will be responsible of notifying the LEA regarding title change 

within 30 days providing name, firm, mailing address, and telephone number of 

the new owner. 

The CIDPW, as the landfill operator, will be responsible for post-closure 

personnel (maintenance and monitoring), the Site Engineer, and other postclosure contractors. 

4.3 LANDFILL GAS MIGRATION MONITORING AND MAINTENANCE 

The proposed landfill gas migration monitoring system program described in this 

section provides the methods and procedures required to detect migrating 

landfill gas. The proposed monitoring wells will be installed around the perimeter 

of the landfill as part of closure construction (see Appendix J). 

4.3.1 LANDFILL GAS MIGRATION MONITORING PROCEDURES 

PCFS FCPCMP 

Monitoring procedures for the gas migration monitoring system will include 

inspection of the subsurface monitoring wells for verification of proper operation. 

All probes will be monitored for methane to ensure that the concentration does 

not exceed 25 percent of the lower explosive limit (LEL) in facility structures 

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(excluding gas control or recovery system components) or the LEL for methane 

at the facility property boundary. The monitoring events shall be conducted on a 

quarterly basis, at a minimum in accordance with 40 CFR 258.23(b}(2}. This 

monitoring program has been determined based on the criteria specified in 40 

CFR 258.23(b}(1 }. 

4.3.2 LANDFILL GAS MIGRATION MONITORING REPORTING 

The results of the gas migration monitoring program will be submitted to the 

USEPA, the Quechan Tribal Council within 90 days of sampling unless 

compliance levels are exceeded. The results will include the concentration of 

total hydrocarbons in each probe along with information involving personnel and 

general conditions in which the sample was obtained. 

Should the compliance levels be exceeded, immediate necessary steps will be 

taken to ensure protection of human health and notification of the USEPA and 

Quechan Tribal Council will occur. Within seven days of detection of an 

exceedance, the methane gas levels and a description of corrective action will be 

placed in the operating record in accordance with 40 CFR 258.23(c). Within 60 

days of detection, a remediation plan for the control of methane gas releases will 

be implemented. A copy of the remediation plan will be placed in the operating 

record and the USEPA and Quechan Tribal Council will be notified that the plan 

has been implemented. The plan will describe the nature and extent of the 

problem and proposed follow-up actions in accordance with 40 CFR 

258.23(c}(3}. It should be noted that the USEPA may develop an alternative 

schedule for demonstrating compliance with 40 CFR 258.23(c}(2} and (c}(3}. 

4.3.3 MAINTENANCE OF LANDFILL GAS MIGRATION MONITORING SYSTEM 

PCFS FCPCMP 

The general maintenance requirements for the gas migration monitoring system 

are limited to replacing broken valves and fittings. As previously discussed, gas 

probes will be inspected at the time of monitoring for proper operation. Any 

deficiencies will be corrected immediately. 

The following equipment will be utilized, as needed, for maintenance, repair or 

replacement of probes for the gas migration monitoring system: 

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• Various hand tools including hand saws, pipe cutters, electric drills, pipe taps, 

wrenches, hammers, hand or electric pump and/or shovels. 

• Backhoe. 

Equipment which may be needed to perform probe installations: 

• Drill Rig. 

• Front end loader. 

• Dump truck. 

• Drillers maintenance truck. 

• Various hand tools needed to perform work including: shovels, generator, 

temporary support blocks. 

• Safety equipment including: hard hat, goggles, gloves, steel toe rubber boots, 

overalls, safety belt and respirator. 

• Additional equipment may also be needed due to certain environmental 

conditions, as required, in the site safety plan. 

Materials 

• PVC pipe 

• Compression fittings 

• Threaded pipe caps 

• PVC labcock valves 

• Teflon tape 

4.4 GROUNDWATER, LEACHATE AND SURFACE WATER MONITORING 

PCFS FCPCMP 

The purpose of the monitoring program discussed in this section is to detect any 

migration of contaminants to the groundwater from the closed waste disposal 

area. Initially, because California is a U.S. EPA-approved State regulating solid 

waste facilities within the State, the site was thought to fall under the jurisdiction 

of the California Regional Water Quality Control Board - Colorado River Basin 

Region, and site monitoring was performed in accordance with site-specific 

Waste Discharge Requirement No. 88-005, and the more recent blanket Waste 

Discharge Requirements No. 93-071, established for all active landfills within the 

Colorado River Basin Region and prepared to comply with federal regulations. 

As a result, the groundwater monitoring program for the site has been performed 

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in accordance with the groundwater sampling and analysis plan (included in 

Appendix C) and these WDRs. However, the site is located on Tribal land, and 

therefore, it is subject to federal regulations. To fully comply with federal 

regulations, an SSFR was prepared requesting a modification to the list of 

detection monitoring parameters provided in 40 CFR Part 258.54(a)(1) and (2) 

(Appendix C-1 ). 

There are no surface water bodies at or near the site. The Picacho wash, which 

passes along the eastern side of the property, rarely contains surface water, 

except for short periods of time immediately after a significant rain event. 

As discussed in Section 2.2, the CIDPW is currently working on submitting a 

Notice of Intent (NOI) under the Multi-Sector General Permit and developing a 

Stormwater Pollution Prevention Plan (SWPPP) and Stormwater Monitoring Plan 

(SWMP) for the PCFS. 

The PCFS site does not have nor is required to install a leachate collection and 

removal system, therefore, no leachate monitoring or maintenance procedures 

are discussed herein. 

4.4.1 GROUNDWATER MONITORING PROCEDURES 

PCFS FCPCMP 

CIDPW monitoring personnel (or its subcontractors) will conduct the 

groundwater monitoring program described in Appendix C during the entire 

post-closure period. It is expected that modifications to program frequency and 

protocols will take place, depending upon changing conditions, results of 

monitoring and advancing technology. This plan will be amended to include any 

changes in the monitoring program or modifications to the system including any 

proposed remediation systems. 

The existing groundwater monitoring system at the PCFS consists of three 

monitoring wells (P-MW-1, 2, and 4) and one water level measuring station (PDW-3A). One additional groundwater monitoring well (P-MW-5) is proposed as 

part of closure. All of the groundwater monitoring wells are being monitored in 

accordance with site specific WDR No. 88-005, and blanket WDR Order No. 93-

071, which were established by the Colorado River Basin RWQCB for all active 

landfills within the Colorado River Basin Region. Because the site is located on 

Tribal land, federal regulations administered by the U.S. EPA govern the site 

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program. Therefore, a SSFR has been prepared recommending a modified the 

list of detection monitoring parameters from those listed within 40 CFR 258.54(a) 

and generally consistent with the current monitoring program. 

The current groundwater sampling and analysis program is included in Appendix 

C. All groundwater samples will be analyzed for routine monitoring parameters 

including chloride, nitrate as nitrogen, pH, sulfate, total dissolved solids, arsenic, 

and the 40 CFR 258 Appendix I list of volatile organic compounds (VOCs) as 

outlined in the groundwater sampling and analysis plan included in Appendix C 

on a semi-annual basis. The lowest possible analytical detection limits will be 

used so that the method detection limits are below currently established 

regulatory MCLs. In addition, the groundwater monitoring wells are analyzed for 

the full suite of COCs listed in Appendix II of 40 CFR, Part 258. COC sampling 

was last performed at the PCFS in August 2006. Following construction of well 

P-MW-5, samples from this well will be analyzed for the entire Appendix I list of 

monitoring parameters including the 15 metals as specified in 40 CFR 258, for 

two semiannual monitoring periods before routine sample analyses are 

performed at this well. 

4.4.2 GROUNDWATER MONITORING EVALUATION AND REPORTING 

PCFS FCPCMP 

After data are received from the laboratory, the data will be qualitatively 

evaluated prior to performing statistical analyses. The data will be evaluated by 

reviewing the quality control information that is included with the laboratory 

report. The quality control information provided by the laboratory will include 

measures of accuracy, precision, and sample contamination. The quality control 

information will be reviewed to determine that the quality control measures such 

as percent recovery and relative percent difference are within acceptable ranges, 

as determined by the laboratory. If these measures are outside the acceptable 

range, the laboratory will be asked to provide written documentation to explain 

the cause or potential cause for the failure to meet the quality control 

acceptance criteria. If the quality control acceptance criteria are not met, then 

the associated laboratory results are questionable and will not be included as 

part of the statistical analysis. Immediate resampling of the wells will not be 

performed unless the analysis for VOCs is deemed invalid. Otherwise, samples 

will be collected during the following scheduled semiannual sampling event. 

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PCFS FCPCMP 

The laboratory data, particularly inorganic parameters, will also be reviewed for 

outliers and anomalies. Outliers and anomalies are unusually or inconsistently 

large or small values that may be influenced by sampling, laboratory, shipping, or 

transcription errors. To date, sufficient historical databases for each well and 

analyte have been assembled so that data anomalies or outliers can be identified 

using statistical or comparative methods. If additional wells or analytes are 

added to the routine groundwater monitoring program, a minimum of eight 

measurements will be required before analysis of outliers or data anomalies can 

be conducted. To assist in detecting outliers, time-series charts of analyte 

concentrations will be produced for each constituent for each well. If a 

significant trend or an anomalously high result is observed, then field and 

laboratory procedures will be evaluated. If the source of an error cannot be 

determined and the laboratory results from the subsequent sampling event 

provide similar results, then the data will be considered reliable and be used for 

statistical analysis. If the laboratory results from the subsequent sampling event 

do not verify the previous data, even if the source of error cannot be determined, 

then the outlier or anomalous sample point will be removed from the database 

for the purpose of statistical evaluation. 

Statistical Methodology 

The recommended statistical method to be employed is by prediction interval, 

intra-well comparison, which compares the groundwater chemistry data 

collected from each individual well through time. This is considered appropriate 

because of the shallow site gradient, which results in some seasonal variability in 

the designation of upgradient and downgradient wells, the extensive databases 

for each well (at least 20 discrete sampling events), and generally similar 

upgradient and downgradient groundwater chemistries. 

Under this method a correlation equation is calculated for each well and each 

analyte for which there are at least eight data points, based on the historical data, 

and a "normal" range of values is predicted for the following monitoring period. 

If the value of the last sampling period is inconsistent with the historical data 

trend, then contamination is suspected. This method is consistent with the 

statistical technique of prediction intervals recommended by the 40 CFR 

258.53(g). 

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PCFS FCPCMP 

For organic compounds (VOCs, pesticides, etc.), alaboratory-specific Practical 

Quantitation Limit (PQL) will be used as its statistical concentration limit. 

Because the calculation of the laboratory-specific PQLs incorporates a measure 

of statistical uncertainty associated with the measurement process, any detected 

organic compound that is verified at a concentration above the PQL is 

statistically significant. Laboratory-specific PQLs will be periodically recalculated 

in accordance with 40 CFR, Part 136, or equivalent. If organic compounds are 

found and verified in samples from a well, statistical methods as described in the 

following section will be used. 

Detection Verification Procedure 

If one or more compounds are detected at concentrations in excess of the 

appropriate statistical limit as described above, then verification sampling will be 

performed. The schedule of verification sampling will be as follows: 

Organic Compounds: If one or more compounds is detected above the 

PQL, verification sampling will be immediately scheduled for collection 

from the well that produced the original significant detection. 

Inorganic Constituents: If one or more inorganic compounds is detected 

at above its respective statistical limit, then verification sampling will occur 

during the next regularly scheduled sampling event. 

If the laboratory results of the verification samples confirm that the 

concentrations of the subject compounds are above their statistical limits, then 

the _US EPA- Region 9 will be notified and assessment monitoring in 

accordance with 40 CFR 258.55 will begin. 

Trend Analyses 

Analysis of groundwater quality data trends will be performed as an annual 

reporting requirement for the PCFS in support of the semiannual intrawell 

statistical analyses. Trend analyses will be performed by plotting the 

concentrations of a groundwater analyte over five years or the period of time 

that a well has been sampled whichever is less. Time-series charts will be 

prepared for each well or analyte and the historical data will also be compared 

with Federal maximum contaminant levels (MCLs), as appropriate. For the 

VOCs, and other organic compounds, charts will be prepared for each VOC that 

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PCFS FCPCMP 

has been regularly detected at least 1 0 percent of the time in samples from at 

least one monitoring well. Significant increasing trends in laboratory measured 

analyte will be used as a way of assessing changes in the groundwater chemistry 

indicative of release from the landfill. 

Assessment Monitoring 

When one or more detection monitoring parameters is measured at a statistically 

significant concentration, in accordance with 40 CFR 258.55, assessment 

monitoring will begin. At the onset of an assessment monitoring program, 

groundwater samples will be collected and analyzed within 90 days for all of the 

parameters listed in Appendix II of 40 CFR, Part 258 and annually thereafter. The 

USEPA may specify an alternate frequency for the repeated sampling and 

analysis of the full assessment monitoring parameters. The USEPA may also 

specify an appropriate subset of wells to be sampled and analyzed during 

assessment monitoring. 

After a minimum of four sample sets of the detected assessment monitoring 

parameters have been analyzed, background concentrations and groundwater 

protection standards will be established for the detected assessment monitoring 

parameters. If the concentrations of all assessment monitoring parameters are 

shown to be at or below background concentrations for two consecutive 

sampling events, the USEPA will be notified, and assessment monitoring will end, 

and detection monitoring will resume. If the concentrations of any of the 

assessment monitoring parameters are detected at statistically significant 

concentrations above the background concentrations but below the 

groundwater protection standards, then assessment monitoring will continue. 

If the concentration of an assessment monitoring parameter is detected at a 

statistically significant concentration above both the background concentration 

and groundwater protection standard, then the USEPA will be notified within 14 

days. The nature and extent of the contamination will be characterized with the 

installation of at least one additional monitoring well at the facility boundary in 

the direction of contaminant migration, in accordance with 40CFR 258.55(g)1 (ii). 

Persons who own land or reside on land that directly overlies any part of the 

contamination plume will be notified. Also, an assessment of corrective 

measures will be initiated within 90 days of finding that an assessment 

monitoring parameter is above background concentration and the groundwater 

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protection standard. Assessment monitoring will continue during the assessment 

of corrective action phase. 

A demonstration that the source of contamination other than the landfill caused 

the contamination detected during the course of groundwater monitoring, or 

that the statistically significant increase resulted from an error in sampling, 

analysis, statistical evaluation, or natural variation in groundwater quality, may be 

submitted for review and approval by the USEPA. If a successful demonstration 

is made, then assessment monitoring may continue, though assessment of 

corrective action will not be pursued. 

Semi-annual monitoring reports will be prepared in accordance with the site's 

groundwater monitoring program and WDRs. The reports will be submitted to 

the USEPA- Region 9 and the Tribal Council. Every five years, the results of the 

COC testing will be incorporated into the semi-annual monitoring report. 

4.4.3 GROUNDWATER MONITORING SYSTEMS MAINTENANCE 

PCFS FCPCMP 

The groundwater monitoring wells must be serviced and maintained to allow the 

wells to perform to the proper standards for which they were designed. 

Monitoring wells will be inspected at least semi-annually during sampling to 

determine if the well has been tampered with or damaged and to verify that the 

well cover is secure. If well damage is observed or if sampling equipment cannot 

be used to collect a sample, the condition will be noted and CIDPW will be 

informed of the nature and extent of corrective action. All necessary 

maintenance and/or repairs for wells will be documented using the sample Form 

C included in Appendix G. 

In the event that a well may need to be replaced, a California licensed driller is 

recommended to be used to drill and construct any replacement well. The 

replacement well is recommended to be designed by a California registered 

geologist (RG) or professional engineer (PE) in accordance with "California 

Department of Water Resources" (DWR Bulletin 7 4-90). All drilling and well 

construction activities are recommended to be under the direct supervision of an 

RG or PE. Note that the California Department of Water Resources does not 

have authority over the PCFS, which is located on land governed by the 

Quechan Tribal Council. 

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If a groundwater monitoring well becomes unusable or unrepairable, it is 

recommended that the well be abandoned following RWQCB procedures in 

accordance with "California Well Standards: California Department of Water 

Resources" (DWR Bulletin 7 4-90). 

Well repairs, which typically include well development, are considered CIDPW 

projects and as a result, they will go out to bid to qualified contractors. The bid 

preparation and selection process, mobilization, and well repair will typically 

require approximately three to six months to complete. It should be noted that 

the Site Engineer will be employed by either CIDPW or an outside contractor, 

who will report directly to the Director of the Department of Public Works. 

4.5 FINAL COVER INSPECTION AND MAINTENANCE 

PCFS FCPCMP 

Post-closure care of the final cover will be maintained and repaired, as needed, in 

accordance with 40 CFR 258.61 (a)(1 ). The purpose of the completed final cover 

is to: 

• Minimize storm water infiltration into and through the closed landfill, 

• Minimize the venting of gas generated in the facility, 

• Isolate the buried wastes from the surface, 

• Promote drainage, 

• Minimize erosion or abrasion of the cover, and 

• Accommodate settlement and subsidence so that cover integrity is 

maintained. 

The primary purpose of the final cover maintenance procedures is to maintain 

the integrity of the completed final cover over the long-term and provide 

maintenance, scheduling and documentation so that materials and maintenance 

practices are consistent with the final cover design specifications. Quarterly 

visual inspections of the final cover will include identification of any erosion and 

settlement problems and slope stability issues. The Site Engineer will be 

responsible for documenting the location and extent of any repairs. As indicated 

in Section 4.4.3, the Site Engineer will be employed by either CIDPW or an 

outside contractor, who will report directly to the Director of the Department of 

Public Works. 

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4.5.1 PERIODIC LEAK SEARCH/IDENTIFICATION OF PROBLEM AREAS 

All employees with access to the site will be instructed to report any final cover 

surface cracking, ponding or unusual surface conditions to the Site Engineer, who 

will record the information in the site logbook at the time they are observed. 

Scheduled, formal inspections will be performed on a quarterly basis by grid 

walking the site to visually observe the following: 

• Evidence of erosion 

• Visible depressions 

• Ponded water 

• Odor 

• Exposed refuse 

• Cracks 

• Settlement and subsidence 

• Slope failure 

• Leachate seeps 

In addition to routine inspections, the site will be inspected following any major 

storm event, seismic event, or natural disaster. The drainage control facilities will 

also be inspected quarterly for improper operation and resultant effects on the 

surrounding final cover. A formal report of findings is to be presented to the Site 

Engineer. 

4.5.2 MAINTENANCE PROCEDURES 

PCFS FCPCMP 

The proposed final cover designed for the PCFS consists of a two-foot thick 

foundation layer composed of select soil materials, a minimum one foot of which 

has been determined to be in-place by the recent existing cover evaluation and a 

two and a half foot thick layer of on-site or near-site soil material that will 

comprise the monolithic vegetative cover layer (Figure 6). 

All final cover repair and/or reconstruction activities shall be conducted in a 

manner directed to maintain the integrity of the as-built final cover system. 

Repair of fill materials should be performed in six to eight inch layers and 

procedures utilized during the original final cover construction. Any repair of the 

final cover will require removal of the pit run rock and soil surface. The rock 

surface should be scraped from the area requiring repair and stockpiled for 

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PCFS FCPCMP 

placement upon completion of the repair. The following methods of repair are 

recommended for the following two modes of final cover distress: 

• Settlement related sags and drainage interruptions, which interfere with the 

controlled flow and discharge of surface waters from the closed landfill 

surface. 

• Surface erosion as a result of drainage channel"overflow" associated with 

intense rains. 

Final cover repair activities will be conducted and documented as specified in 

the CQA Plan. 

Sags, Ponds, Drainage Interruptions and Surface Erosion 

Any minor repair of depressions in the final cover shall be completed in the 

landfill area on an annual basis immediately prior to the rainy season (October 

15 to April 15). If significant sags or ponds are identified during other times of 

the year, the Site Engineer shall accurately locate the limits of the depressions 

both horizontally and vertically and required repairs shall be completed as soon 

as possible. 

A channel capable of draining the lowest point of the sag will be constructed or 

additional soils will be placed such that the intended flow of surface water is 

unimpeded. The Site Engineer will be responsible for fill placement occurring 

only in the area of the sag; only that fill which is necessary to facilitate drainage is 

placed; and that sufficient record of the depths and limits of fill placement are 

kept. The depth and limit records should always be available so that the 

appropriate area can be re-excavated and permanently repaired during the 

annual maintenance period, if necessary, as discussed below. 

The permanent repair of sags and ponds, when necessary, will be performed by 

excavating to the undisturbed soils and adding any select soil material necessary to 

maintain a positive gradient and rebuilding to at least two percent gradient, if 

possible. In areas of drainage interception and surface erosion, reconstruction will 

be consistent with the materials and practices utilized during closure construction. 

All records of cover repair will be kept in the record library. A certified engineering 

geologist will inspect and certify repairs to the final cover layer. 

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4.6 LANDFILL SETTLEMENT MONITORING 

Settlement monitoring every five years is adequate at PCFS due to the following 

factors: 1) settlement is expected to be relatively slow based on the arid climate 

and the shallow depth of refuse and related low overburden pressure; and 2) the 

systems, which can be affected by differential settlement (i.e., final cover and 

drainage control), will be inspected on a much more frequent basis than every 

five years so potential issues will be identified without more frequent settlement 

monitoring. If the regulatory agency(ies) determine that the frequency should 

occur more often, then the initial monitoring will be conducted on a bi-annual 

basis with a reduction in frequency to every five years, if substantiated by the 

results of the first two monitoring events. 

4.7 ACCESS ROAD MAINTENANCE 

The site access road will be inspected during the final cover inspection on a 

quarterly basis for cracks and pot holes. If any large cracks or pot holes large 

enough to collect water are noted, the affected area will be repaired in 

accordance with the final cover repair procedures discussed in Section 4.5.2. 

4.8 DRAINAGE SYSTEM INSPECTION AND MAINTENANCE 

The following sections delineate the various maintenance activities to be 

performed on the landfill drainage facilities for the deck and slope areas. Figure 5 

shows the location of the surface water drainage control facilities and Section 3.7 

provides a description. 

After the control system has been in service for several years, a more definitive 

inspection and maintenance schedule can be developed identifying those 

facilities that must be inspected annually, those facilities that must be inspected 

prior to and after a storm and those facilities that require maintenance before the 

rainy season. 

4.8.1 DECK DRAINAGE CONTROL SYSTEM FEATURES MAINTENANCE 

PCFS FCPCMP 

Inspection for proper deck surface drainage (i.e. diversion berms, grading, etc.) 

will be performed in conjunction with the final cover procedures described in 

Section 4.4.2. It is important that maintenance vehicles utilize access roads 

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provided on the decks and benches whenever possible to reduce surface rutting 

which could interfere with the designed drainage patterns. 

4.8.2 DOWNDRAINS, DRAINAGE CHANNELS, BASINS AND DITCHES 

A visual inspection of each downdrain, open channel and basin will be 

conducted to identify any of the following deficiencies: 

• Cracking 

• Settlement 

• Spalling 

• Presence of silt and/or debris 

The following corrective measures can be taken for deficiencies identified during 

the inspection. 

• Cracking 

- Construction of expansion/control joints 

- Resurface 

- Replacement 

• Settlement 

- Grout injection 

- Complete replacement with subgrade rework 

• Spalling 

- Sandblast affected area and resurface 

- Sawcut and remove affected area, dowel into existing undamaged section 

and resurface 

• Clogging by Silt/Debris 

- Vacuum pumps 

- Waterjet spray 

- Bucket line 

- Fire hose flushing 

The downdrains, open channels and basins shall be inspected annually for debris 

build-up prior to the rainy season and after high intensity storm events. 

4.8.3 OVERALL DRAINAGE MAINTENANCE SCHEDULE 

The on-site drainage facilities must be free of debris and operational at all times. 

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In order to provide the desired protection against flooding and erosion damage 

routine inspections of the drainage control system will be conducted as shown 

on Table 4. 

A written report will be prepared for all scheduled inspections and will be kept 

on file with the Site Engineer. In addition, all inspection forms will be placed in 

the record library as required by 40 CFR, 258.29. Form E included in Appendix 

G is a standard inspection form, which can be used for this purpose. 

4.9 SITE SECURITY INSPECTION AND MAINTENANCE 

4.10 

4.1 0.1 

4.10.2 

PCFS FCPCMP 

Security fencing, access gates and signs will be inspected quarterly to ensure that 

the integrity of site security has been maintained. The gates will be inspected to 

ensure that the locks are intact. Any necessary repairs or replacements will be 

made during the quarterly inspection. On an annual basis, the fence will be 

inspected for corrosion and rust, and maybe repainted as necessary to maintain 

the aesthetic quality of the site. 

EQUIPMENT, LABOR AND MATERIAL REQUIREMENTS 

EQUIPMENT 

The equipment schedule presented in Table 5 delineates the specific type of 

equipment, instruments and tools expected to be used for post-closure 

maintenance. Any required equipment not available for on-site use, when 

necessary, will be rented on an "as needed" basis. 

LABOR 

The work force necessary to monitor and maintain the PCFS during post-closure 

will be directed and coordinated by designated personnel. Staff will be assigned 

to each of the following activities: 

• Final cover, landscape, drainage and general maintenance 

• Environmental monitoring and reporting 

The maintenance and monitoring personnel will be under the direction of a Site 

Engineer or geologist where appropriate. 

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PCFS FCPCMP 

The projected maintenance schedule for each of the post-closure activities is 

shown on Table 4. The primary purpose of this schedule is to identify the 

frequency of mandatory inspections for the various systems. The frequency of 

sampling and analysis for the groundwater, perimeter gas probes and settlement 

monuments will be in accordance with the monitoring schedule presented in 

Table 6. 

Any additional personnel needed for surveying or drilling will be provided 

through outside contractors. 

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SECTION 5.0 

POST-CLOSURE EMERGENCY RESPONSE PLAN 

BRYAN A. STIRRAT & ASSOCIATES 
5.0 POST-CLOSURE EMERGENCY RESPONSE PLAN 

5.1 PURPOSE AND SCOPE 

This Emergency Response Plan (ERP) was prepared in accordance with 27 CCR, 

Section 21130 since 40 CFR, Part 258 does not require this plan, as part of the 

PCFS FCPCMP. The ERP identifies occurrences that may exceed the design of 

the site and endanger public health or the environment. The ERP also sets forth 

actions that will minimize the effects of these catastrophic events. The provisions 

of this ERP will be carried out immediately whenever an event occurs such as a 

fire, explosion, flood, earthquake, vandalism, surface drainage problems or 

release of any waste product which may threaten public health and/or the 

environment. The ERP will be kept in the operating record at the CIDPW Main 

Office. 

5.2 SITE SAFETY OFFICER 

The Site Engineer will have the responsibility of Site Safety Officer (SSO). The 

SSO will be trained to handle all emergency situations. The main responsibility 

of the SSO is to oversee the management of all emergency response procedures 

implemented at the landfill. The SSO is required to be thoroughly familiar with 

all aspects of the ERP as well as all post-closure maintenance activities, the 

location and characteristics of buried refuse, the location of facility records and 

the overall site layout. In addition, the SSO shall be given the authority to 

commit any of the available resources necessary to carry out the ERP. 

5.3 EMERGENCY RESPONSE NOTIFICATION PROCEDURE 

PCFS FCPCMP 

When any member of the site's maintenance personnel discover or witness an 

event, which constitutes an emergency situation, they shall determine the nature, 

source, and location of the emergency situation and immediately report the 

occurrence to the SSO. The SSO will notify all of the appropriate response 

agencies to provide assistance to site personnel. If an emergency event occurs 

when field personnel are not on-site, the general public will be able to use the 

telephone number posted on a sign to be located at the site entrance to notify 

the SSO. The emergency telephone number will be responded to 24 hours a 

day. 

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5.4 EMERGENCY RESPONSE PROCEDURES 

General emergency response procedures for fire, explosions, earthquakes, 

floods, vandalism, release of waste products to air and soil, or surface drainage 

problems, are described below. 

• Remove all non-essential employees from the vicinity of the incident. 

• Remove non-essential equipment, if it can be done safely, from the vicinity of 

the incident. 

• Determine and identify the nearest source of available equipment and 

supplies for responding to the incident. 

• Determine the degree of risk to human health and safety for persons to be 

working in the vicinity of the emergency prior to sending in people to control 

the emergency. 

• Determine the immediate risk to the environment. If the risk is imminent, it 

should be determined whether or not the emergency can be safely isolated 

to minimize damage to the environment. 

• Determine the appropriate agencies to call given a particular type of 

emergency. 

• When practicable, the SSO may utilize on-site personnel to control the 

incident. 

• The Site Superintendent or his designee will be responsible for site personnel 

safety. Site personnel will communicate any damage and/or injury reports to 

the SSO and will coordinate all emergency actions directed by the SSO. 

• Site personnel will be available for inspection of the landfill after an incident 

occurs. All crew members will be supplied with appropriate personal 

protective clothing, as required by the SSO, when conducting inspections of 

the site for possible design failure. All findings will be reported to the SSO for 

action. 

• The SSO will immediately begin surveillance in those areas of the facility 

affected by the incident. In addition, monitoring will be conducted to 

prevent an incident from affecting other areas of the facility or adjacent 

properties. 

• Shut down any control system, which have been damaged during an incident. 

• The operator will maintain a small stockpile of final cover material for those 

events, which may require immediate cover placement to minimize waste 

releases, to repair severe cracks, or to fill in large erosion gullies. 

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The general types of equipment and materials that should be available for 

emergencies include a cellular phone, first aid kit, air supplies, fire extinguisher, 

final cover material, and sandbags. All action steps for the following emergency 

procedures should be done in as short a time period as possible to prevent 

adverse health and safety affects to the public. 

5.5 FIRE AND/OR EXPLOSIONS 

The following procedures will be followed during incidents of fire and/or 

explosions: 

• Contact the County of Imperial Fire Department, even if on-site capabilities 

are deemed adequate to extinguish fires or control future explosions. On-site 

landfill personnel will be instructed to follow the Fire Department's directions 

and give their full cooperation. 

• In the event of an off-site fire near the landfill, such as a brush fire, the 

operator will lend its personnel and equipment, if available, to the Fire 

Department to fight the fire. 

• The fire will be extinguished and the effects of the fire or explosion will be 

mitigated. 

The following are the general telephone numbers for emergency response 

agencies: 

• Imperial County Fire Department (760) 355-1191 

• Imperial County Sheriff's Department (760) 339-6302 

• Office of Emergency Services (800) 852-7550 

• Imperial County Public Works Department (760) 482-4462 

• Imperial County Division of Environmental Health (760) 336-8530 

• Tribal Police, as needed (760) 572-2933 

• Tribal Environmental Department, as needed (760) 572-2969 

• Bureau of Indian Affairs (Regional Office), as needed (602) 3 79-6600 

• Tribal Emergency Response (760) 572-0213 

5.6 FLOOD 

PCFS FCPCMP 

If the site's existing stormwater diversion berms are inadequate in diverting flood 

waters away from the site, the following procedures will be followed: 

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• Additional berms may be constructed in areas prone to flooding. 

• If additional berms are ineffective, the operator may cut a diversion channel 

to avoid inundation of the refuse cell. 

• Sandbags may be used in conjunction with berms or diversion channels. 

5.7 EARTHQUAKE 

The following procedures will be performed following an earthquake incident: 

• Employees driving in the field during an earthquake should stop their vehicle 

and get out, if it can be done in a safe manner. 

• After the earthquake has subsided, site personnel shall report to the site 

entrance gate for a roll call. If medical care is required, the procedures in 

Section 5.1 0 shall be followed. An inspection of the site shall then be made 

and a report given to the SSO. 

• Cracks observed in the final cover after an earthquake should be inspected 

with a combustible gas analyzer. The location of venting and the gas 

concentrations will be determined and reported to the SSO. Excavation and 

refill of the smaller surface cracks can be completed immediately. More 

extensive corrective actions will be authorized by the Site Engineer in 

accordance with the CQA Plan included in Appendix 1 of Appendix D. 

5.8 SURFACE DRAINAGE PROBLEMS 

In the event of a surface drainage problem, the following procedures shall be 

followed: 

• The operator will investigate the problem and determine a necessary course 

of action. 

• If a surface inlet is blocked with debris, all necessary labor forces and 

equipment will be implemented under the direction of the operator to 

remove the blockage. 

• If a storm drain is damaged, a plan will be provided by the Site Engineer to 

repair the problem. 

• After the drainage problem is corrected, an assessment of possible damage or 

erosion will be conducted and all necessary repairs will be made. 

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5.9 VANDALISM 

The following procedures will be followed during incidents of vandalism: 

• Repair (i.e., replace, repaint) any portion of the property which has been 

vandalized. 

• Immediately repair any vandalism, which affects site security and/or 

environmental control/monitoring systems. 

• A review of the adequacy of site security after each incident shall be 

performed and those measures will be revised, if needed. 

5.10 UNDERGROUND FIRES 

Underground landfill fires occur due to air intrusion into the refuse cell. 

Indicators of underground fires are as follows: 

• Unusual depression-like settlement with tension cracks 

• Smoke/steam 

• Unusual odor 

Should any of the above indicators be noted, the first course of action should be 

placement of soil to cover the depression and/or cracks. If this measure does 

not correct the problem, additional measures may be taken under the direction 

of the SSO. 

5.11 EMERGENCY RESPONSE PLAN ORIENTATION 

Contacts should be made with appropriate emergency response agency 

representatives and the following information should be conveyed: 

• Familiarize them with the layout of the facility, the properties of the waste 

materials deposited, and the evacuation routes. 

• Establish understandings between the responding Police/Sheriff and Fire 

Departments and designate which agency has primary emergency authority 

during an incident. 

• Establish understandings between emergency response teams, emergency 

response contractors, and equipment suppliers for smooth coordination of 

emergency response actions. 

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5.12 EVACUATION PROCEDURES 

During and/or after an incident, the SSO in consultation with other emergency 

personnel, such as the Fire Department, will assess the potential for injury to any 

persons located on adjacent properties. If the assessment concludes that an 

imminent threat to public health is possible, an evacuation of the nearby area will 

be initiated. Situations, which warrant partial or complete evacuation of site 

personnel and/or local residents, are as follows: 

• Explosions resulting in airborne debris including particles and large fragments. 

• Fires that cannot be readily contained or are spreading to other parts of the 

facility; or when fire could generate highly toxic fumes, or create a danger of 

igniting potentially explosive substances which may be stored on-site. 

The SSO will immediately notify the responding Police/Sheriff Department and 

all other appropriate emergency response agencies. The SSO will check that the 

entrance gate is unlocked and locked as required. 

5.13 MEDICAL CARE PROCEDURES 

Should an emergency situation result in personal injury, immediate steps will be 

taken to determine the cause and extent of the injury and to render first aid. The 

SSO will be notified in all cases and the paramedics will be called when required. 

If further medical attention is necessary, the injured person will be transported to 

the nearest medical facility. 

5.14 AMENDMENTS TO THE EMERGENCY RESPONSE PLAN 

PCFS FCPCMP 

The ERP will be reviewed and can be amended, in accordance with the criteria 

listed in 27 CCR, Section 21130(c). The amendment criteria are as follows: 

• A failure or release occurs for which the plan did not provide an appropriate 

response. 

• The post-closure use and/or structures on the site change and these changes 

are not addressed in the existing plan. 

• The LEA, the RWQCB or the CIWMB notifies the operator in writing that the 

current emergency response plan is inadequate under the provisions of this 

section. The notifying agency shall include within the written notice those 

items that must be considered for the plan to be in compliance with this 

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section. The operator shall submit an amended ERP to the Quechan Indian 

Tribe, LEA, the RWQCB and the CIWMB within 30 days of receipt of 

notification that the plan is inadequate. 

Whenever the ERP is amended, a written copy will be submitted to the Quechan 

Tribal Council. 

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SECTION 6.0 

CLOSURE/POST-CLOSURE MAINTENANCE COST ESTIMATE 

BRYAN A. STIRRAT &ASSOCIATES 
6.0 CLOSURE/POST-CLOSURE MAINTENANCE COST ESTIMATE 

6.1 INTRODUCTION 

In order to establish the basis for the proper level of funding to close and provide 

post-closure maintenance for the PCFS in an environmentally sound manner, a 

cost estimate was prepared reflecting closure plan features and post-closure 

maintenance procedures presented in Section 4.0 of the this FCPCMP. This 

estimate was then combined with an estimate for construction 

management/quality assurance services to determine the total closure cost. This 

closure and post-closure cost estimate then serves as the basis to fund the 

closure account over the life of the landfill. 

6.2 CLOSURE COST ESTIMATE 

The plan features are grouped into categories for convenience in presenting the 

estimate. A brief description of the components included in each category is 

given below. The closure cost estimate, as shown in 201 0 dollars, is shown on 

Table 7. 

6.2.1 FINAL COVER 

PCFS FCPCMP 

The PCFS disposal area at closure will be 12.5 acres. The planned final cover for 

the deck and slope areas consists of a two-foot thick foundation layer composed 

of select soil materials, a minimum one foot of which has been determined to be 

in-place by the recent existing cover evaluation, and a two and a half foot thick 

layer of select soil material that will comprise the monolithic vegetative cover 

layer with a soil/pit run rock admixture layer in the upper six to eight inches. The 

cost of constructing the final cover includes the use of on-site or near-site select 

soils, import of pit run rock material for the soil/pit run rock admixture, site 

preparation, and closure plan integration with the existing groundwater 

monitoring system. The final grading cost also includes access road/staging area 

construction. 

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6.2.2 FINAL COVER CONSTRUCTION QUALITY ASSURANCE 

Costs for construction quality assurance include the final cover placement tests, 

inspections and reporting. 

6.2.3 DRAINAGE CONTROL SYSTEM 

Costs for drainage system improvements include the deck and V-channel 

drainage improvements for the landfill. 

6.2.4 EROSION CONTROL 

This category covers the cost of soil preparation and mixture of pit run rock 

materials into the top six inches of the monolithic vegetative layer as discussed in 

Section 3.3. 

6.2.5 GAS MIGRATION MONITORING SYSTEM 

This category includes costs for installation of four multiple-depth gas migration 

monitoring probes around the perimeter of the PCFS as discussed in Section 3.8. 

6.2.6 GROUNDWATER MONITORING SYSTEM 

No costs are associated with this category since no additional groundwater 

monitoring wells are planned to be installed at closure. 

6.2.7 SITE SECURITY 

This category includes costs for installation of additional perimeter fencing to 

secure the entire filled area of the site at closure. This category also includes 

signage as discussed in Section 3.11. 

6.2.8 DEMOLITION 

PCFS FCPCMP 

This category includes costs for dismantling and removal of the landfill scales and 

scalehouse. 

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6.2.9 CLOSURE CERTIFICATION REPORT 

6.2.10 

6.2.11 

This category includes costs for preparation of a report certifying the final cover 

placement. 

ENGINEERING DESIGN PLANS AND SPECIFICATIONS 

This category includes costs for preparation of construction level engineering 

design plans and specifications for bid purposes. This cost estimate is assumed 

to be five percent of the total construction cost estimate. 

CONSTRUCTION MANAGEMENT 

The construction management cost for closure of the landfill is based on an 

estimated 3-month construction schedule. 

6.3 POST-CLOSURE MAINTENANCE COST ESTIMATE 

The post-closure maintenance cost estimate has been prepared utilizing 

information contained in Tables 3 through 5 and estimates of manpower, 

material and equipment to maintain the PCFS in compliance with current 

applicable regulations. 

The total annual maintenance and monitoring cost estimate for post-closure is 

shown on Table 8. These costs are projected in 2010 dollars, assuming no 

change in the regulatory environment with respect to the PCFS. In the event that 

changes occur in the regulatory conditions pertaining to the PCFS, if necessary, 

revised post-closure cost estimates will be submitted to the USEPA, the Quechan 

Tribal Council, CIDPW, and LEA. 

6.4 DEMONSTRATION OF FINANCIAL RESPONSIBILITY 

PCFS FCPCMP 

In accordance with Subtitle D, Subpart G, the CIDPW must demonstrate 

financial responsibility for closure and post-closure costs. The CIDPW has 

established an enterprise fund for closure costs and a Pledge of Revenue has 

been established for post-closure maintenance costs to comply with financial 

assurance requirements of 40 CFR 258.71-72. Subsequent to their review of the 

FCPCMP for PCFS (dated May 1999; revised: June 2009), the United States 

Environmental Protection Agency - Region 9 approved the revised cost estimate 

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PCFS FCPCMP 

included in the aforementioned FCPCMP and found that the CIDPW meets the 

Local Government Test for allowable mechanisms as outlined in 40 CFR 

258.74(f). 

A copy of the most up-to-date closure and post-closure cost estimate can be 

found in the operating record. The closure and post-closure cost estimates are 

adjusted for inflation annually as required by 40 CFR 258.71-72. 

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SECTION 7.0 

RECORDKEEPING 

BRYAN A. STIRRAT & ASSOCIATES 
7.0 RECORDKEEPING 

7.1 OPERATING RECORD 

A complete operating record will be maintained in accordance with Federal 

regulations 40 CFR 258 (Section 258.29 Recordkeeping Requirements and 

Section 258.60 Closure Criteria). Closure and post-closure activities will be 

documented in the operating record and will include, but will not be limited to, 

the following information: 

• Any location restriction demonstration required by 40 CFR 258, Subpart B; 

• Inspection records, training records, and notification procedures required by 

40 CFR 258, Section 258.20; 

• Gas monitoring results from monitoring and any remediation plans required 

by 40 CFR 258, Section 258.23; 

• Any MSWLF unit design documentation for placement of leachate and gas 

condensate in a MSWLD unit as required under 40 CFR 258, Section 

258.28(a)(2); 

• Any demonstration, certification, finding, monitoring, testing or analytical data 

required by 40 CFR 258, Subpart E; 

• Closure and post-closure care plans and any monitoring, testing, or analytical 

data required by 40 CFR 258, Sections 258.60- 258.61; 

• Any cost estimates and financial assurance documentation required by 40 

CFR 258, Subpart G; 

• Any information demonstrating compliance with small community exemption 

as required by 40 CFR 258, Section 258.1 (f)(2); and 

• Notice of intent to close the unit, notice of certification of closure, and deed 

notation as required by 40 CFR 258, Section 258.60. 

It should be noted that the operating record will also contain that information 

compiled during active operations as required by applicable Federal regulations. 

7.2 LOCATION AND INSPECTION OF OPERATING RECORDS 

PCFS FCPCMP 

The operating records will be maintained at the CIDPW's Main Office. In 

accordance with 40 CFR 258, Section 258.29, the CIWMB has been notified of 

the alternative location (i.e., the Main Office) of the operating record for the 

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PCFS FCPCMP 

PCFS. These records are open for inspection during normal business hours by 

authorized representatives of those regulatory agencies having jurisdiction over 

the PCFS. 

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SECTION 8.0 

REFERENCES 

BRYAN A. STIRRAT & ASSOCIATES 
8.0 REFERENCES 

1. Code of Federal Regulations Title 40, Parts 257 and 258. 

2. California Code of Regulations, Title 27, Chapters 3 and 4. 

3. Blake, T.F., 2000a, EQFAULT, A Computer Program for the Estimation of Peak 

Horizontal Acceleration from 3-D Fault Sources, Version 3.00b, Updated 2004. 

4. Blake, T.F., 2000b, EQSEARCH, A Computer Program for the Estimation of Peak 

Horizontal Acceleration from California Historical Earthquake Catalogs, Version 

3.00, Updated 2009. 

5. Bray, J.D., and Rathje, E.M., 1998, "Earthquake-Induced Displacements of SolidWaste Landfills," Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 

March, Vol. 124, No.3. 

6. Bray, J.D., E.M. Rathje, A.J. Augello, and S.M. Merry, 1998, Simplified Seismic Design 

Procedure for Geosynthetic-Lined, Solid Waste Landfills, Geosynthetics International, 

Vol. 5, Nos. 1-2, 1998. 

7. Bryan A. Stirrat & Associates, Inc., June 1995, Revised August 1995, 11Preliminary 

Closure and Post-Closure Maintenance Plan. 11 

8. Imperial County Public Works Department, March 1995, 11Periodic Site Review, 

Picacho Solid Waste Site, Winterhaven, California. 11 

9. Herzog Associates, October 1988, 11Solid Waste Water Quality Assessment Test 

(SWAT) Proposal, Picacho Solid Waste Disposal Site, County of Imperial, California. 11 

10. ENVIRON Corporation, August 1994, "Work Plan Ground Water Monitoring 

Program Ocotillo, Salton City, Hot Spa, Niland, Palo Verde and Picacho Landfills. 11 

11. Campbell, K.W., 1993, 11Empirical Prediction of Near-Source Ground Motion from 

Large Earthquakes," Proceedings, International Workshop on Earthquake Hazard and 

Large Dams in the Himalaya, Sponsored by the Indian National Trust for Art and 

Cultural Heritage (INTACH), New Delhi, India, January 15-16. 

12. Loeltz, O.J., Irelan, B., Rubison, J.H., and Olmsted, F.J., 1975, 11Geohydrologic 

Reconnaissance of the Imperial Valley, California, U.S. Geological Survey 

Professional Paper 486-K. 11 

13. Moore & Taber, 1988, 11Seismic and Hydrogeologic Review, IT Corporation Class I 

Waste Disposal Site, Imperial County, California. 11 

14. Newmark, N.M., 1965, "Effects of Earthquakes on Dams and Embankments," 

Geotechnique, Vol. 15(2), pp. 139-160. 

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1 5. Singh, S., and Murphy, Bruce, "Evaluation of the Stability of Sanitary Landfills", In: 

Ceotechnics of Waste Fills - Theory and Practice, ASTM STP 1 070, Arvid Landvia, 

G. David Knowles, editors, American Society for Testing Materials, Philadelphia, 

1990. 

16. County of Imperial, Department of Public Works, Imperial Solid Waste Sites, Waste 

Volume and Remaining Capacity, and Quarterly Solid Waste Reports. 

17. California Integrated Waste Management Board, September 8, 1998, letter re: 

Adequacy of the Closure/Postclosure Maintenance Fund for the Worthington, 

Calexico, Ocotillo, Holtville, Palo Verde, Brawley, Niland, Hot Spa, Salton City, 

Picacho. 

18. California Regional Water Quality Control Board - Colorado River Region, 1988, 

"Waste Discharge Requirements Order No. 88-5." 

19. California Regional Water Quality Control Board- Colorado River Region, 1993, 

"Amended Waste Discharge Requirements Order No. 93-071." 

20. California Integrated Waste Management Board, 1980, "Solid Waste Facilities Permit 

No. 13-AA-0012." 

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