EPA/600/R-12/700
An Evaluation and Analysis of Past Landfill Closures
in Puerto Rico as Guidance for Current and Future
Closures
STREAMS Task Order 99
EPA Contract Number: EP-C-05-060
Prepared for.
United States Environmental Protection Agency
Office of Research and Development
National Risk Management Research Laboratory
Cincinnati, Ohio
Prepared By:
Innovative Waste Consulting Services, LLC
Gainesville, Florida
Under Subcontract To:
RTI International
Research Triangle Park, North Carolina
HRTI
INTERNATIONAL
September 2011
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EPA/600/R-12/700
Contents
Contents i
Executive Summary vi
Introduction 1
Project Background 1
Report Organization 1
Analysis Methodology 2
Field Observations 2
Hydraulic Conductivity of Site Cover Soils 2
Methane Surface Emissions Monitoring 5
Historical Information Review 6
Field Evaluation 8
Sites Evaluated 8
Rincon Landfill 1 9
Background Information 9
Field Observation Results 12
Field Measurement Results 14
Rincon Landfill 2 15
Background Information 15
Field Observation Results 16
Field Measurement Results 19
Cabo Rojo 20
Background Information 20
Field Observation Results 23
Field Measurement Results 25
Vieques 26
Background Information 26
Field Observation Results 27
Field Measurement Results 30
Table of Contents
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EPA/600/R-12/700
Discussion and Recommendations 31
Discussion 31
Access Control 32
Environmental Monitoring and Control Systems 32
Maintenance 33
Waste Mass Stability 34
Final Cover 34
Recommendations 35
Recommendations to Further Investigate Targeted Sites 35
Recommendations for Future Closures 36
References 39
Appendix A - USGS Quadrangle Maps and Approximate Site Boundaries 1
Appendix B - Supplemental Photographs 1
Appendix C - Rincon Landfill Hydraulic Conductivity 1
Appendix D - Cabo Rojo Landfill Hydraulic Conductivity 1
Appendix E - Viegues Landfill Hydraulic Conductivity 1
Appendix F - Supplemental Site Figures: An Evaluation and Analysis of Past Landfill
Closures in Puerto Rico as Guidance for Current and Future Closures 1
Table of Contents
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
LIST OF FIGURES
2-1 Guelph Permeameter in use at the Closed Rincon Landfill 3
2-2 Guelph Permeameter Field Test Flow Chart 3
2-3 Conceptual Schematic of Guelph Permeameter Apparatus 4
2-4 Field Team Member Taking a Reading with the Portable FID 6
3-1 Location of Selected Closed Landfill Sites of Interest in Puerto Rico 9
3-2 Aerial Photograph of Rincon 1, Inferred Waste Boundary, and Approximate
Location of Groundwater Monitoring Wells 12
3-3 Landscape View of Rincon 1 Looking to the North 13
3-4 Stockpile of Sorted Plastics at the Rincon (1) Municipal Landfill 14
3-5 Surface Emissions Monitoring Path at Rincon 1 15
3-6 Aerial Photograph of Rincon 2 and Approximate Waste Boundary 16
3-7 Eroded Western Edge of Rincon 2 17
3-8 Stratification of the Western Edge of Rincon 2 18
3-9 Ditch to the east of the Closed Rincon Landfill 19
3-10 Methane Surface Emissions Monitoring Path and Guelph Permeameter Test
Location at Rincon 2, Rincon, Puerto Rico 20
3-11 Aerial Photograph of the Closed Cabo Rojo Municipal Landfill and Approximate
Waste Boundary 21
3-12 Closure Signage Posted at the Closed Cabo Rojo Municipal Landfill 24
3-13 Vegetation on the Side Slopes at the Cabo Rojo Municipal Landfill 25
3-14 Aerial Photograph of the Closed Cabo Rojo Municipal Landfill with Approximate
Waste Boundary, Surface Emissions Monitoring Path, and Hydraulic Conductivity
Measurement Location 26
3-15 Aerial Photograph of the Closed Vieques Landfill and Approximate Waste
Boundary 27
3-16 Sagging Fence at the Closed Vieques Landfill 28
3-17 Herd of Horses Grazing at the Closed Vieques Landfill 29
3-18 Recent Waste Deposits at the Closed Vieques Landfill 29
3-19 Surface Emissions Monitoring Path and Guelph Permeameter Test Location at
the Closed Vieques Landfill, Vieques, Puerto Rico 30
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
LIST OF TABLES
3-1 Closed Landfill Sites of Interest Targeted During the Project 8
3-2 Groundwater Well Inspection Data from a 2002 JCA Site Inspection 11
4-1 Summary of Visual Assessment Criteria 31
LIST OF APPENDICES
A -USGS Quadrangle Maps and Approximate Site Boundaries
B -Supplemental Photographic Log
C -Hydraulic Conductivity of Cover Soil at the Rincon Landfill
D -Hydraulic Conductivity of Cover Soil at the Cabo Rojo Landfill
E -Hydraulic Conductivity of Cover Soil at the Vieques Landfill
F -Supplemental Site Figures
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Executive Summary
The Resource Conservation and Recovery Act of 1976 (RCRA) establishes the minimum
standards for the design, operation, and closure for municipal solid waste landfills in the
United States and its territories. In Puerto Rico, the Regulations for Non-Hazardous Solid
Waste Management provide the framework for compliance with RCRA. In the past,
landfills in Puerto Rico have not always been closed in accordance with the minimum
federal and state regulations. Various issues including the use of appropriate materials
for closure, installation and utilization of environmental monitoring equipment, and
waste mass stability have raised questions regarding the impact of these facilities on
human health and the environment.
The United States Environmental Protection Agency's (US EPA) Office of Research and
Development (ORD), in cooperation with US EPA Region 2, contracted RTI International
(RTI) to evaluate past landfill closures in Puerto Rico and provide recommendations for
current and future closures. Innovative Waste Consulting Services, LLC (a subcontractor
to RTI), and representatives of US EPA ORD traveled to Puerto Rico in March 2011 to
conduct several site investigations at closed landfills in different geographic regions of the
island. Four landfills were visited and the conformity of the site to closure criteria in
federal and Commonwealth regulations was evaluated. The field team conducted visual
assessments, measured surface methane emissions, and measured the hydraulic
conductivity of the final cover soil at the sites.
The following are recommendations to address issues at the landfills targeted in this study
based on the field evaluations and subsequent historical document review:
Conduct a detailed final cover analysis to more accurately assess the extent of final cover
construction as well as hydraulic performance of the in-place soils.
Evaluate groundwater quality and the presence of subsurface gases.
Identify potential beneficial uses for the sites.
In addition to the above specific recommendations to address the closed landfills visited
during this project, the following recommendations are offered that may help improve
landfill closures in the future.
Install and maintain access control infrastructure at all MSW landfills.
Install and maintain the minimum-required final cover or consider alternative,
performance-based cover systems, such as evapotranspiration covers.
Design and construct above-grade side slopes to a maximum 3:1 (H:V).
Design and install stormwater management infrastructure.
Maintain existing gas collection infrastructure.
Monitor groundwater and perimeter gas.
Executive Summary vi
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Construct and maintain leachate collection systems and conduct a comprehensive
assessment of leachate quality and leachate management on the island.
Assess beneficial use options for other closed landfills or landfills that will be closed in the
near future.
Based on the results of the field visits, additional evaluation of other closed landfills in
Puerto Rico is warranted, which would include a more detailed assessment of potential
risk to human health and the environment, and perhaps an assessment of options to
mitigate these potential risks. A combination of field testing, anecdotal information
collection from municipality officials and local regulatory agencies, and historical
document review could provide US EPA with the necessary tools to assist decision makers
on how to best move forward with addressing closed landfills of concern.
Executive Summary vii
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Introduction
Project Background
The island of Puerto Rico has faced several challenges related to the issue of closed landfills
- historically, many municipal landfills in Puerto Rico were not closed properly or
abandoned, while others were closed in accordance with applicable rules but have sustained
physical changes from climatic and human events that have rendered them less secure. As
a result, some closed landfills may pose a risk to human health and the environment
presently and in the future. The Office of Research and Development, United States
Environmental Protection Agency (US EPA) awarded Task Order 99, "An Evaluation and
Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures"
under its Scientific, Technical, Research, Engineering, and Modeling Support (STREAMS)
contract to RTI International (RTI). RTI subcontracted a portion of the technical work to
Innovative Waste Consulting Services, LLC (IWCS). The project was conducted to provide US
EPA Region 2, whose jurisdiction includes Puerto Rico, with information to understand the
current conditions of a subset of closed landfills and provide Region 2 personnel with
recommendations for evaluating future closed landfills in Puerto Rico.
A field study was developed to evaluate four municipal solid waste landfills (representing
different geographic regions in Puerto Rico) over the course of two field days (with
approximately 3 to 4 hours spent at each site) by gathering information through observation
and conducting limited field testing to understand the successes and shortcomings of
previous closures. The field data were then supplemented by reviewing available historical
documentation for each of the four subject sites to understand what, if any, engineering
design or controls were put in place at the time the landfill closed.
Report Organization
This report is organized into five sections. Section 1 provides an introduction to the project.
Section 2 describes the analysis methodology. Section 3 presents a discussion of the site
selection, historical information review, and field study results. Section 4 provides a
discussion of the project results and recommendations for future study. Section 5 lists the
references used in developing this report.
Supplemental information is provided in a series of appendices. Appendix A contains USGS
Quadrangle maps for each site. Appendix B includes a log of photographs taken during each
site visit to supplement those included in this report. Appendix C, D, and E include calculation
packages to estimate hydraulic conductivity at three of the sites. Appendix F provides
supplemental figures for the sites visited.
Introduction
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Analysis Methodology
The first task of the project was to develop a set of criteria that would be used to evaluate
each of the selected sites. Given the screening-level nature of the project, the project team
worked to develop evaluation criteria that could be used to efficiently assess conditions
(since the project scope included an aggressive schedule of visiting four sites spread across
the island in two days) at a given site while causing minimal disturbance to the site. The
project team held several telephone conferences in late 2010 and early 2011 to develop the
site evaluation criteria. Ultimately, the field schedule and the desire to collect data during
field visits guided the decision-making process. A quality assurance project plan (QAPP) was
developed and submitted to the US EPA QA officer for approval prior to beginning the field
visits.The following sections describe the major elements of the plan that were developed
to evaluate the closed sites.
Field Observations
The intent of the field observations was to evaluate the presence and condition of
monitoring and control structures at the site as well as observe the overall condition of each
site. The assessment was intended to be only qualitative in nature. The specific items or
conditions that were targeted during the field observation of each site included:
Access control (e.g., fencing, locking gate, signage)
Cover soils (presence or absence, evidence of erosion, presence or absence of vegetation)
Stormwater controls (evidence of ponding, presence or absence of stormwater control
infrastructure and condition of such infrastructure)
Leachate controls (presence or absence)
Nuisance conditions (presence or absence of windblown litter, leachate seeps, odors, and
disease vectors)
Environmental monitoring and/or control infrastructure (presence or absence of gas
monitoring wells, groundwater monitoring wells, and gas collection wells)
Each metric was evaluated through sensory observation and documented with photographs.
Hydraulic Conductivity of Site Cover Soils
The Resource Conservation and Recovery Act (RCRA) established the minimum design
standards for municipal solid waste (MSW) landfills in the United States and its territories,
which includes design criteria for final cover soils at landfills.
According to 40 CFR 258.60(a)(l), all MSW landfills must have, at a minimum, a final cover
system constructed to "have a permeability less than or equal to the permeability of any
bottom liner system or natural subsoils present, or a permeability no greater than 1 x 10"5
cm/sec, whichever is less." Rule 565 of the Puerto Rico Regulations for Non-Hazardous Solid
Waste Management established the same minimum criteria. Given that the subject facilities
for this project are old, closed landfills, the hydraulic conductivity criterion of 1 x 10"5 cm/sec
was used as an evaluation metric.
Analysis Methodology 2
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Hydraulic conductivity can be measured in the field and in the laboratory through different
empirical and experimental methodologies. The apparatus selected to measure field
hydraulic conductivity of soils for this project was the Guelph Permeameter (Soilmoisture
Equipment, Santa Barbara, CA). The instrument is a constant-head device that operates on
the Mariotte siphon principle. This device was selected because a given test can be
completed in a couple of hours and the unit is fairly easily transportable. Figure 2-1 shows
the permeameter in use at one of the sites visited during the study.
Figure 0-1. Guelph Permeameter in use at the closed Rincon Landfill
Figure 2-2 presents a flow chart that shows the decision-making process that was used in
the field as part of taking a hydraulic conductivity measurement.
Step 1:
Select test
location
o
Step 2:
Excavate Hole
Step 3:
Evaluate Soil
Characteristics
Step 4:
Conduct field
test
Figure 0-2. Guelph Permeameter Field Test Flow Chart
Analysis Methodology
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Step 1: The field team identified areas of the landfill that were fairly flat and free of debris
and thick vegetation and the specific area for the test was selected.
Step 2: At the selected sampling location, a borehole was advanced using a hand-held
auger until the desired depth was reached (typically 4 to 6 in. below grade). If a borehole
could not be advanced this deep (from refusal because of a rigid object or if the borehole
could not maintain its integrity), Step 1 was repeated. A stiff-bristle brush was used to
prepare the borehole so that the smearing effect (which could provide erroneous
measurements) would be reduced.
Step 3: During borehole advancement, the auger's spoils were visually classified using a
soil classification guide provided in the permeameter user manual. Step 4: The equipment
was assembled, the appropriate testing method was selected, and the hydraulic
conductivity measurement process was initiated. Figure 2-3 shows a simplified schematic
of the Guelph Permeameter.
Composition and profile of
underlying material varies
Figure 0-3. Conceptual Schematic of Guelph Permeameter Apparatus
Prior to initiating measurements, the permeameter was assembled and centered over the
borehole, and the outlet tip was lowered to the bottom of the hole. The reservoir was filled
with water (about 2 gallons) and was then sealed with the supplied cap. The instrument
includes two reservoirs: an inner reservoir (used alone if the percolation rate is expected to
be low) and an outer reservoir (used in combination with the inner reservoir when
percolation rates are expected to be relatively high).
A one-head or a two-head procedure can be used with the instrument. The one-head
procedure allows for more rapid measurement of hydraulic conductivity. The one-head
procedure was selected for measurement at all sites because of the expected percolation
Analysis Methodology
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
rate and the number of sites that were targeted for analysis, which was also consistent with
the time available to conduct the field study.
Once the reservoir configuration was selected, the test was started by raising the upper air
tube and water height indicator to a constant head of 5 cm. As the water percolated into the
soil, the water level in the reservoir(s) fell. Readings were taken using the internal graduated
cylinder over a given time interval, typically ranging from a 1-minute interval (in cases where
water moved fairly quickly into the soil) to a 3-minute interval (when water percolated more
slowly through the soil).
The rate of fall was calculated throughout the procedure by dividing the drop in water level
by the time interval between readings. Once the rate of fall stabilized for a minimum of three
consecutive readings, the steady-state rate of fall was calculated and the measurement
procedure was concluded.
After obtaining the steady-state rate of fall from the permeameter, the data collected in the
field were used to calculate the hydraulic conductivity using procedures and equations
provided in the instrument's manual. The hydraulic conductivity of the selected cover soil at
each site was then compared to the RCRA and the Puerto Rico Non-Hazardous Solid Waste
Management criterion of 1 x 10~5 cm/sec.
Methane Surface Emissions Monitoring
Methane surface emissions monitoring is typically performed at MSW landfills to help
evaluate the operations of an active gas collection system and is not typically required as
part of post-closure care activities at facilities that do not have active gas collection. The New
Source Performance Standards (NSPS) for MSW Landfills (Subpart WWW) sets methane
concentration limits (500 parts per million (ppm)) above which additional action must be
taken to remediate issues with the gas collection system. Although none of the sites targeted
for this project were expected to have active gas collection, the project team used the 500
ppm level as an initial criterion with which to compare measurements of methane surface
concentrations at each targeted site.
A portable TVA Foxboro 1000B Vapor Analyzer with a flame ionization detector (FID) was
used to measure methane surface concentrations at each of the targeted landfills. The
instrument was operated using the "scan" mode whereby samples for methane
concentration (in units of ppmv) are collected continuously by the instrument. The
instrument was powered on, the internal flame was ignited, and the instrument ran for
approximately 10 minutes (per the instrument's operating manual) prior to starting
calibration procedures. The instrument was calibrated using a certified 500-ppm methane
standard in accordance with the instrument's operating procedures.
Where access was available, an upwind and a downwind background reading (based on the
assumed limits of the landfill and wind conditions at the time of measurement) were taken
with the instrument. The operator then slowly traversed the landfill unit's surface in a
serpentine pattern at a spacing of approximately 100 ft, taking methane concentration
measurements continuously with the instrument's sample probe located 2 to 4 inches from
the landfill's surface. The path traveled on each landfill surface was determined based on
Analysis Methodology
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
the conditions in the field and generally avoided large obstructions (e.g., vegetation or
debris) and steep slopes (greater than a 3 horizontal to 1 vertical). Figure 2-4 shows a project
team member taking a reading with the portable FID.
Figure 0-4. Field Team Member Taking a Reading with the Portable FID
A hand-held readout device was monitored by the operator during measurement. If the
detected methane concentration began to increase, the operator paused and waved the
monitoring probe above the surface to find the potential area of high methane
concentration until the reading stabilized. Initially, the project team intended to note all
locations where a reading greater than 500 ppm was measured; however, as a result of the
low concentrations measured in the field, all measured concentrations above the
background levels were noted and recorded in a field log book.
Historical Information Review
The project team completed the site selection process a couple of weeks prior to mobilizing
- as described in Section 3.1, the targeted sites and the sites that were accessible differed
slightly. Given the fluid nature of the selected sites, historical documentation for each of the
sites that were visited was requested from the local Puerto Rico regulatory agency, Junta de
Calidad Ambiental (JCA) immediately following completion of the field visits. The documents
that were available to the project team included historical design documents for two of the
Analysis Methodology
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
landfills that were visited (Rincon 1 and Cabo Rojo). Limited additional information was
found on the other two sites that were visited through literature searches, information
provided by the US Fish and Wildlife Service, and publicly-available sources.
The historical information was used to attempt to fill data gaps that existed based on
observations made during site visits. Available historical information was reviewed to
understand basic site characteristics such as the operating years, type of waste received, and
area and depth of waste disposal. Additionally, the historical information was reviewed to
identify potential regulatory compliance issues, evaluate whether a formal closure plan was
designed for each facility and what the details of those closure plans were as well as whether
the closure plan was followed (in whole or in part) based on field observations.
Analysis Methodology
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Field Evaluation
Sites Evaluated
The project team initially targeted four closed landfill sites to evaluate during the field effort:
Rincon, Cabo Rojo, Guayanilla, and Vieques. These sites were targeted since they represent
different geographical regions of the island with somewhat varying climatic conditions.
Before the field visits, it was unknown whether these facilities were formally closed with
appropriate engineering controls in accordance with US EPA and JCA rules or were
abandoned or perhaps partially closed. Ultimately, the actual sites visited changed slightly
from the initial target list - Table 0-1 summarizes the sites of interest and provides notation
on those that were visited and those that were targeted but not visited. Figure 3-1 shows
the approximate location of each of the six landfills presented in Table 3-1.
Table 0-1. Closed Landfill Sites of Interest Targeted During the Project
Site
Cabo Rojo
Guayanilla
Rincon (1)
Rincon (2)
Vega Alta
Vieques
Visited During Field
Effort?
Yes
No
Yes
Yes
No
Yes
Notes
Visited on 28 March.
Attempted to visit on 28 March - municipality
officials corresponded with JCA and said the
gates to the facility were locked and thus access
was not possible.
The project team was not aware of this site
before arriving in Puerto Rico. The JCA
representative that accompanied the project
team on 28 March brought the project team to
this facility.
This was the originally-targeted closed landfill in
the municipality, which is located along the west
coast of Puerto Rico. Visited on 28 March.
The project team attempted to secure an escort
to accompany the team to the site on 30 March.
The short notice of the request prevented a
municipality official or a JCA official from
accompanying the project team. Limited
locational data for the site were available and
attempts to find the site were not successful.
Visited on 29 March.
Field Evaluation
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Rincon 2
Figure 0-1. Location of Selected Closed Landfill Sites of Interest in Puerto Rico
Rincon Landfill 1
Background Information
The Rincon Landfill (denoted in this report as Rincon Landfill 1) is located about 0.6 km
southeast of the center of the Municipality of Rincon off of PR-115 (at approximately
18°20'3.57"N, 67°14'42.90"W). The landfill reportedly began operation in 1982 (Garcia,
Cabot, & Asociados 1994). On 10 August 1993 the JCA issued an order to the Municipality of
Rincon to close the landfill (JCA 1996a). A closure plan for the site, prepared in March 1994
by Garcia, Cabot, & Asociados, describes the site as lying on the north-facing slope of a
northeast-striking mountainous ridge terminating at a stream to the north, Quebrada los
Ramos. Furthermore, the closure plan reported a landfill property area ranging from 8.5
acres to 10 acres and a disposal footprint of approximately 6 acres, consisting of municipal
solid waste, scrap iron, and tires (Garcia, Cabot, & Asociados 1994). The landfill was
apparently phased by filling in the southwestern areas of the site and the adjacent valley. A
1966 USGS quadrangle map (which would represent pre-development grades based on
information provided in the closure plan) shows the site topography sloping gently generally
towards the stream with two high points of elevation just to the south and east-southeast
of the landfill - a copy of the USGS quadrangle map for this and the other sites visited is
provided in Appendix A.
Figure 3-2 shows an aerial photograph of the site and an inferred waste boundary based on
information provided in the site's closure plan. A seismic refraction investigation prepared
as part of the closure plan development suggested that the waste in the center of the site
was approximately 4 to 5 m thick. Additionally, the closure plan reported that approximately
103,700 tons of waste were disposed based on the years of operation (1982 - 1994) and
census figures and information from the Puerto Rico Planning Board and Waste
Management Authority. The site was to cease accepting new waste in April 1994 and the
closure was to be certified in October 1994.
The closure plan described several components of the closure system in general terms, but
drawings, details, and specifications were not available. The site's final cover was intended
to have an 18-in. thick clay layer overlain by a high-density polyethylene geomembrane liner
of unspecified thickness, and a 6-in. to 8-in. thick vegetative soil layer. The closure plan also
Field Evaluation
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
mentions that access, vector, fire, and leachate would all be controlled. Additionally, the
plan indicates that a gas collection system would also be put in place as well as a gas and
groundwater monitoring system. The plan proposed three groundwater monitoring wells
(identified as 1, 2, and 3) that would be used to monitor groundwater quality upgradient and
downgradient of the landfill.
Several pieces of correspondence were made available to the project team regarding the
site. A Closure Inspection Report prepared by JCA dated July 1996 noted several items in the
Closure Plan that had been addressed or were being addressed at the time of the inspection
(JCA 1996a). Among those notes was that a clay layer was being installed at the time of the
inspection and that nine gas monitoring wells had been installed. During the inspection, one
groundwater monitoring well was vertically extended so that once the installation of the
final cover was complete, the well would remain accessible. The municipality had also begun
leveling the south slope of the landfill.
The inspection report pointed out that several elements required under the August 1993
Closure Order had not been fulfilled at the time of inspection. In the inspection report, JCA
requested the remediation of several shortcomings in the closure of the site including:
Application of a final 6-in soil erosion layer capable of supporting vegetation.
Implementation of a system to control leachate.
Submission of groundwater monitoring and explosive gas monitoring plans in accordance
with the prescribed regulations
Determination of the exact locations of each groundwater monitoring well installed on
the south slope.
A follow-up inspection in October 1996 found the same deficiencies at the site.
The Municipality of Rincon later submitted a request to JCA to develop an ornamental plant
nursery as an alternative use of the landfill during the post-closure period (a copy of this
request was not available to the project team, but its existence was revealed in a March
2002 JCA response to the request). In its March 2002 response to the request, JCA indicated
that multiple requests (30 May 1996, 30 July 1996,10 December 1996, and 20 March 1997)
had been made by JCA to the municipality to complete closure activities in accordance with
the closure plan submitted to and approved by the governing board. JCA noted that the site
had not yet complied with all of its requirements for closure, and that in order to implement
an alternative use of the landfill a series of conditions must be met including:
The municipality must submit a notification to JCA signed by an engineer licensed in
Puerto Rico that certifies closure activities were performed in accordance with the closure
plan submitted to and approved by the Board.
The municipality must make a note with the land registry indicating that the property was
used as a landfill.
Signs must be maintained which identify the site as a closed landfill.
Field Evaluation 10
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
The final cover must be maintained to prevent erosion problems and exposure of buried
waste.
The monitoring wells must be easily identified and accessed (three monitoring wells were
identified as installed: MW-1, MW-2, and MW-3).
The monitoring wells must be flagged and labeled.
All monitoring wells must have a lock and a cap installed.
Integrity and structural tests on each well must be performed through use of a camera to
check for blockages or breaks in the pipe.
Stormwater runoff channels must be built and maintained.
A leachate collection system must be built and maintained.
A groundwater monitoring plan must be prepared in accordance with RCRA guidance and
submitted.
An explosive gas monitoring plan must be prepared and submitted.
Groundwater sampling must be initiated after JCA's approval of the groundwater
monitoring plan.
Explosive gas monitoring must be initiated following approval of the plan by JCA.
In the March 2002 letter, the JCA also described the findings from a February 2002 site
inspection. During the inspection, the JCA located three groundwater monitoring wells on
site (MW-1, MW-2, and MW-3), evaluated the condition of the wells, measured the depth
of each well, measured the depth to water in each well, and determined the material and
diameter of the pipes. MW-1 and MW-2 were found to be dry. Table 0-2 provides the well
data collected byJCAduringthe site inspection. Figure 3-2 shows the approximate proposed
location of the wells according to the closure plan for the site—no as-built locational data
was available for the wells.
Table 0-2. Groundwater Well Inspection Data from a 2002 JCA Site Inspection
ID
MW-1
Gradient
Up
gradient;
Southeast
Condition
of the
Steel Cover
Acceptable;
No Lock
Well
Dept
h(ft)
93.18
Water
Level
(ft)
Dry
Product
Level
None
Height
and
Diameter
of Case
58'
4"
Well
Diameter
2.0"
Field Evaluation
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Table 3-2 (continued)
ID
MW-2
MW-3
Gradient
Down
gradient;
North
Down
gradient,
West
Condition
of the Steel
Cover
Acceptable;
No Lock
Acceptable;
No Lock
Well
Depth
(ft)
12.73
28.87
Water
Level
(ft)
Dry
27.68
Product
Level
None
None
Height and
Diameter
of Case
3.5'
3.5"
2.54'
5.5"
Well
Diameter
2.0"
4.0"
JCA recommended that the municipality run integrity tests on the wells to evaluate the
presence of obstructions or breaks in the wells. They further recommended that the wells
be evaluated for future use in monitoring activities at the site. The March 2002 letter is the
last piece of correspondence that was available to the project team.
Groundwater Well
Approximate
Waste Limit
Figure 0-2. Aerial Photograph of Rincon 1, Inferred Waste Boundary, and Approximate
Location of Groundwater Monitoring Wells
Field Observation Results
The site was visited on 28 March 2011. The conditions the day of the visit were partly cloudy
with a temperature of 75 °F (Wunderground 2011a). The project team traveled to the site
with guidance from Mr. Harold Gonzalez of JCA. The originally-targeted landfill identified in
the planning stages of the project was thought to be located in the Municipality of Rincon
along the coast - upon arrival at this site, the project team noted that the landfill was not
located on the coast. The project team contacted the US EPA Region 2 regional
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
representative, Mr. Carl Plossl, upon this discovery and after discussion with US EPA and the
team, a decision was made to conduct only field observations and limited measurements at
this newly-identified landfill so that the project schedule could still be maintained.
Although the entire perimeter was not accessible or visible at the time of the visit, fencing
was in place along the southern edge of the property near the site entrance. The main
entrance to the site, located to southwest of the site, had a gate and signage. A majority of
the site (approximately two-thirds) was covered with a layer of mulch of indeterminate
thickness (Figure 3-3). It was unclear whether a topsoil or clay layer was present beneath the
mulch cover. Additional photos of the site are included in the photographic log in Appendix
B.
Figure 0-3. Landscape View of Rincon 1 Looking to the North.
A plant nursery was present on the central-western portion of the site as well as three other
buildings. The aerial photograph shown in Figure 3-2 was dated 2006 and appears to show
the site as mostly vegetated, suggesting that the mulch layer has been placed in the last 5
years. The mulch appeared to consist mostly of ground-up dimensional lumber.
The site had a mostly flat terrain and the southern edge met with a near-vertical rock slope.
The northern portion of the site's top deck declined at a steep slope (likely greater than 3
horizontal to 1 vertical). The steep slopes prevented detailed visual inspection of the slopes
and the northern toe of the slope.
No leachate seeps were observed on the top surface of the landfill. Localized piles of newly-
placed garbage (mostly bagged municipal solid waste and loosely-placed vegetative waste)
were present at the northern edge of the site and a large pile of sorted plastics were found
at the southern edge of the site (Figure 3-4). Information provided by an individual that was
in one of the on-site buildings indicated that the Municipality of Rincon routinely picks up
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
the bottles and hauls the bottles off site. Additionally, electronic waste was found in a small
utility trailer near the entrance of the facility.
Figure 0-4. Stockpile of Sorted Plastics at the Rincon (1) Municipal Landfill
No objectionable odors or vectors were noted. While on site, a municipal employee visited
with the project team and indicated that MSW is picked out of the waste deposits twice a
week and that only yard waste is left on site. According to the employee, plastics are
stockpiled and collected twice weekly.
No groundwater monitoring, subsurface gas monitoring, leachate control, or stormwater
control features were observed on the accessible portions of the site. As described earlier,
three monitoring wells were reportedly installed at the site as of 2002. The project team did
not have possession of these historical data prior to the field visit and the field visit was
limited to the apparent disposal portion of the footprint. Although exact locational data are
not available for the three monitoring wells, the proposed locations in the site's closure plan
indicate the wells may be located outside of the landfill's property boundary. The historical
correspondence between the municipality and the JCA suggested that the groundwater
monitoring wells were not readily identifiable (the correspondence requested that flagging
and other high-visibility identifiers be installed at each well to facilitate discovery of the
wells).
Field Measurement Results
Figure 3-5 shows the approximate waste limit based on historical information and the
approximate methane surface emissions monitoring (SEM) path followed at the site. No
methane surface concentrations exceeded 500 ppm during the monitoring period.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Furthermore, no concentrations of methane above background were detected. As
mentioned previously, the field measurement was limited to only methane surface
emissions so that the other targeted facilities could be visited within the project team's field
schedule. The SEM path that was taken as shown in Figure 3-5 covers the portion of the site
that had a mulch layer in place. The project team did not have historical information about
the site's actual disposal footprint prior to the field study, so the SEM evaluation was limited
to the area which the team suspected had historical waste disposal.
Figure 0-5. Surface Emissions Monitoring Path at Rincon 1
Rincon Landfill 2
Background Information
The second Rincon (referred to herein as Rincon 2) landfill occupies a stretch of the coastline
of approximately 4.5 acres in western Rincon and is located off of PR-115 (at approximately
18°20'15.57"N, 67°15'13.98"W). Figure 3-6 shows an aerial photograph of the site and the
approximate waste boundary based on an assessment of the field conditions, anecdotal
information provided by local citizens that live on or near the site, and information provided
by US EPA. The landfill was reportedly operated from the 1950s to the 1960s based on
information contained in an e-mail written in 2009 from the US Fish and Wildlife Services to
the US EPA Region 2 (US FWS 2009). Anecdotal information collected at the site suggested
that the landfill was operated by the Municipality of Rincon. A 1966 USGS Quadrangle map
shows the topography of the site as relatively flat.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Approximate
Waste Limit
Figure 0-6. Aerial Photograph of Rincon 2 and Approximate Waste Boundary
Field Observation Results
Rincon 2 was visited on 28 March 2011. The temperature during the site visit was 75 °F with
partly cloudy skies (Wunderground 2011a). Mr. Harold Gonzalez, JCA, accompanied the
project team to the site. Based on visual inspection, the site had an undulating grade
throughout and was bounded on the west by the Caribbean Sea and on the east and north
by residences. The southern, northern, and eastern boundary of the waste was inferred
based on visual inspection.
The site did not have fencing or other means to control access - no lockable gate or signage
was visible at the site upon entry. Furthermore, three homes were constructed within the
landfill's footprint. The site appeared to be subject to open dumping, particularly in the
southern portion of the site. It was unclear whether the materials dumped at the site was
waste generated from the residences located on the landfill or if the materials came from
elsewhere.
The presence and thickness of cover soil at the site varied throughout the landfill. It was
unclear whether any soil cover had been installed as part of closure or compliance activities
- anecdotal information from residents that live on the site indicated that any soils present
were put in place by the residents and not as part of any closure activity. Beach sand covered
portions of the landfill on the western edge. Exposed waste was found occasionally in areas
with insufficient cover. Vegetation was established over a portion of the site but mostly
appeared to be minimally controlled. Trees and bushes populated the eastern and southern
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
portions of the site including some fruit-bearing trees located in apparent areas of buried
waste. Visible waste deposits included materials that had been placed in recent years as well
as layers of waste that had been placed historically as seen on the western and eastern edge
of the site.
A large portion of the western edge of the site was in direct contact with the waves of the
Caribbean Sea (Figure 3-7). Anecdotal information from the residents at the site suggested
that the landfill historically extended further to the west but had been eroded over the years
(Figure 3-8), though an estimate of how far to the west the landfill extended historically was
not known. An ana lysis of erosion of the coastline Rincon conducted by the USGS suggested
that the stretch of coastline where the landfill lies has been subject to substantial erosion
with an average recession rate of 1.1 m/year (USGS 2007). Thus, it is possible that the landfill
was larger and extended further west at one time. Because of the proximity of the landfill to
the sea and the impact of the tides on the landfill, the western slopes of the landfill ranged
from relatively flat to 1-4 ft thick vertical walls.
Figure 0-7. Eroded Western Edge of Rincon 2
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Figure 0-8. Stratification of the Western Edge of Rincon 2
Leachate seeps were not witnessed directly; however, since much of the western edge of
the waste is exposed to the tides, leachate (by definition) is constantly being generated and
discharged into the sea. A small area of riprap was emplaced along a south-facing portion of
beach. Anecdotal information gathered from residents during the site visit suggested that
the riprap was placed to reduce the amount of waste washout towards the north. The riprap
was mentioned in the previously-referenced US Fish and Wildlife Service e-mail and
indicated that the riprap had caused further erosion in the unprotected sand beach. A ditch
that ran along the eastern side of the landfill contained a liquid that appeared to be leachate,
but this ditch appeared to be an area where the nearby residents discharged their
wastewater, so a differentiation between potential leachate and municipal wastewater was
not possible (see Figure 3-9). No leachate control systems were found at the site.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Figure 0-9. Ditch to the east of the Closed Rincon Landfill.
Objectionable odors were present at the southern portion of the site in an area that
appeared to have an animal carcass as well as along portions of the eastern edge of the site
where the accumulated wastewater was present. Vectors (e.g., flies) were present
throughout the site.
No groundwater monitoring wells, subsurface gas monitoring probes, or stormwater
management features were observed during the site visit.
Field Measurement Results
Figure 0-10 shows the site, the approximate SEM path followed at the site (solid red line),
and the location on the landfill where the Guelph Permeameter test was performed (yellow
dot).
No methane surface emissions were detected above background levels during the
monitoring event. No evidence of a clay cover was present, but the measured hydraulic
conductivity of the site soils (1.3 x 10~4 cm/s) was an order of magnitude greater than the
Puerto Rico Non-Hazardous Solid Waste Management criterion of 1 x 10"5 cm/sec. Appendix
C contains additional details regarding the calculation of the hydraulic conductivity of the
soil at Rincon 2.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Permeameter
Test Location
Figure 0-10. Methane Surface Emissions Monitoring Path and Guelph Permeameter
Test Location at Rincon 2, Rincon, Puerto Rico
Cabo Rojo
Background Information
The Municipality of Cabo Rojo is located in southwestern Puerto Rico in Bo. Boqueron to the
west of PR-301 (at approximately 18° 0'47.09"N, 67° 9'3.35"W). The landfill is adjacent to a
bird sanctuary, the Refugio de Aves de Boqueron. The facility starting accepting waste in the
1970s, was ordered by the JCA to close in September 1993, and a closure plan was prepared
in March 1994 (later revised in September 1994). According to the closure plan, the facility
occupies approximately 10 acres and has approximately 996,000 m3 of waste in place
(Jordan, Jones, and Goulding 1994). A1966 USGS Quadrangle map of the site shows that the
site was constructed largely in a mangrove swamp at an elevation of about 1 m or less.
Comparing pre-development grades on the USGS map to GPS data collected using a hand-
held device during the site visit, the thickness of waste at the site ranges from about 1 to 11
m. Figure 3-11 shows an aerial photograph of the site and the approximate edge of waste
based on site contours and the available historical information.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Figure 0-11. Aerial Photograph of the Closed Cabo Rojo Municipal Landfill and
Approximate Waste Boundary
The closure plan called for the construction of a final cover system which included an 18-
inch compacted clay layer and a soil erosion layer capable of supporting vegetative growth.
The closure plan also specified the construction of several storm water control features
(Jordan, Jones, and Goulding 1994). Following review of the Closure Plan in October 1994,
JCA submitted a request for additional information regarding the following details that were
not included in the closure plan:
Identification of the number and location of groundwater monitoring wells and
subsurface gas probes.
Submission of a groundwater monitoring plan.
Submission of a subsurface gas monitoring plan.
Closure certification signed by an engineer licensed in Puerto Rico.
In 1996, JCA conducted several site inspections at the Cabo Rojo Municipal Landfill (13 June,
2 October, and 3 December). Atthe time of these inspections, as much as 65% of the landfill
had been covered with an apparently "satisfactory" clay cover. The inspection noted that
the clay thickness was estimated at 6 in. The remaining 35% of the landfill was apparently
covered with compacted caliche. The thickness of this layer was estimated at 2-3 ft (JCA
1996b). In addition to the concerns regarding the cover, the inspection report also stated
that the municipality needed to stabilize the west slopes and the slopes adjacent to the
wildlife refuge. Atthe time of the June 1996 inspection, the mayor and site manager of Cabo
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Rojo indicated to JCA that the municipality intended to request a waiver from the governing
board to be exempt from the requirements to monitor groundwater.
The municipality submitted a hydrogeological report prepared by Jordan, Jones, and
Goulding (JJG) for the site in 1996. The report made the case that groundwater monitoring
at the site should not be required because of site-specific hydrogeological conditions -
indicating, among other reasons, that background quality of the water was already poor and
the presence of the landfill would not worsen the conditions based on literature-reported
landfill leachate quality. JCA responded to the report in 1997 by disagreeing with the report's
assertion that groundwater monitoring was not required and ordered that a groundwater
monitoring system be installed per Chapter VII of the Puerto Rico Regulations for Non-
Hazardous Solid Waste Management (JCA 1997c). JCA also noted that a waiver to the
requirement to monitor and track groundwater quality can be granted if the
owner/operator can prove that there is no potential for hazardous contaminants to migrate
from the landfill to the aquifer during the active phase and post-closure period of the site.
Following Hurricane Hortense in 1996, a 2 October site inspection revealed that the facility
had largely been unaffected by the storm, and the municipality should move forward with
closure activities at the site, giving priority to the construction of a leachate collection system
and a gas venting system given the proximity of the site to the wildlife refuge. Specific details
regarding requirements of the leachate collection system and gas venting system were not
available for review; however, JCA noted that the gas ventilation system was of particular
importance given historical subsurface fires at the site (JCA 1996c).
In December 1996, JCA returned to the site for an additional inspection. Rainfall from the
days leading up to the inspection had washed out some of the newly-placed cover material
exposing underlying waste. The inspector noted that the site was operating in accordance
with the rules at the time of the inspection (JCA 1996e).
In April 1997, JCA issued a letter to the municipality notifying them of the findings of an
inspection from the previous month. At the time of the inspection, the municipality had
begun installing fence posts for a perimeter fence. Vegetation had become well-established
on much of the clay layer; however, many areas of the cover had eroded leaving some
underlying waste exposed. In addition, leachate collection and gas venting systems had not
been installed (JCA 1997a).
In September 1999, JCA sent a letter to the Municipality of Cabo Rojo notifying them of
several concerns regarding the closure of the site (JCA 1999). Among the items to be
addressed before the closure could be certified were:
Insufficient clay cover on some areas of the landfill.
Uncontrolled vegetative growth on the surface and side slopes.
Stabilization of all side slopes.
Construction of a stormwater control system.
Construction of a leachate collection system.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Installation of a gas ventilation system.
In the same correspondence, JCA notified the municipality that the closure plan for the
facility had not addressed several requirements including:
The number and location of groundwater monitoring wells.
The number and location of explosive gas monitoring wells.
Preparation and submission of a Groundwater Sampling Plan.
Preparation and submission of an Explosive Gas Monitoring Plan.
In March 2000, the municipality sent a letter to JCA notifying them that ESA Group had been
contracted to develop plans to correct the deficiencies in the closure of the site (Municipality
of Cabo Rojo 2000). In the letter, the municipality stated that ESA would:
Identify the present and future design capacity of the landfill.
Develop a compliance plan for approval by JCA.
Prepare a preliminary design for a new cell at the landfill.
Prepare an operations plan for the site.
Correspondence beyond March 2000 was not available, thus the status of completing the
closure activities is unknown.
Field Observation Results
The site was visited on 28 March 2011 on a partly cloudy afternoon with a strong southerly
wind and a temperature of 86 °F (Wunderground 2011a). Mr. Harold Gonzalez, JCA,
accompanied the project team to the site.
From the main entrance to the landfill off of PR-301, the site was fenced with chain-link
fence, and signage indicating the site as a closed landfill was visible from the road
(Figure 3-12). Barbed wire fencing was present on the south side of the landfill; the presence
of fence along the northern and western sides could not be assessed because of dense
vegetation and steep slopes that limited access to the bottom of the slope. The landfill had
a relatively gentle slope upward towards the west from PR-301. An unpaved access road was
present that ran toward the west from the facility's entrance. The entrance had a gate and
a lock.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
ESTADD LIBRE ASOCIADO DE PUERTO RICO
[Alumcipio Autonomo Oe Cabo Rojo
ANTIGUO VERTEDERO MUNICIPAL
PROHIBIDO
OEPOSITAR BASURA O
CUALQUIER TIPO DE DESECHO EN ESTA AREA
LOS VIQLADORES SERAN PROCESADOS LEGALMENTE
PROHIBIPQ EL PASO
Figure 0-12. Closure Signage Posted at the Closed Cabo Rojo Municipal Landfill
The site's closure plan indicates that the slopes vary in grade from 2% to 50% (or 1:1
horizontal to vertical slope ratio). The combination of heavy vegetation and steep slopes
prevented a detailed visual assessment of the west and north side slopes and limited
assessment of the southern slope (Figure 3-13). Historical reports indicate that slope
stabilization was an issue in the past; however, because the side slopes were generally
inaccessible during the site visit, the degree of slope stabilization could not be assessed.
No groundwater monitoring wells were observed at the site, nor were gas monitoring wells.
Additionally, evidence of leachate controls or storage was not observed. A stormwater ditch
was present along the main road to the east of the landfill but it was unclear if this feature
was constructed as part of the landfill's closure activities, had naturally formed overtime, or
built as part of constructing PR-301. Other than this stormwater ditch, no other stormwater
control features were visible.
From visual inspection, the cover appeared to be a sandy clay. Exposed garbage was visible
in one isolated area. The majority of the accessible portion of the landfill had established
vegetation; however, the vegetated areas were scattered amongst barren areas. The side
slopes also held mature, uncontrolled vegetation including large bushes, tall cotton plants,
and other shrubs. No leachate seeps were found on the accessible portions of the landfill.
No recent waste deposits were found at the site, and no objectionable odors or vectors were
apparent on the landfill surface or accessible side slopes.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Figure 0-13. Vegetation on the Side Slopes at the Cabo Rojo Municipal Landfill
Field Measurement Results
Figure 0-14 shows the approximate path taken during SEM measurements and the location
of the hydraulic conductivity test performed at the site. SEM readings were taken around
the top deck and eastern side slope - as described earlier, the northern, western, and
southern slopes were steep and densely vegetated and thus were excluded from the
monitoring path. Fort the most part, methane was not detected above background levels,
but two areas on the southwest portion of the landfill's top deck exhibited concentrations
of up to 10 ppm.
It took several attempts for the project team to obtain a hydraulic conductivity reading since
the first three test holes advanced had rocks and other debris present, thus disallowing the
auger from reaching the appropriate depth. The field test was ultimately conducted on the
fourth borehole that was advanced. Visual classification of the soil indicated it was clayey
with some silt. The measured hydraulic conductivity of the final cover soil was then
measured to be 4.4 x 10~6 cm/sec. See Appendix D for the calculation of the hydraulic
conductivity of the final cover soil at Cabo Rojo.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Permeameter
Test Location
Figure 0-14. Aerial Photograph of the Closed Cabo Rojo Municipal Landfill with
Approximate Waste Boundary, Surface Emissions Monitoring Path, and Hydraulic
Conductivity Measurement Location
Vieques
Background Information
The island of Vieques is located off the east coast of mainland Puerto Rico. The closed
Vieques landfill site occupies approximately 10 acres on the northern coast of the island off
of PR-200 (at approximately 18° 9'29.26"N, 65°25'38.72"W). Limited historical information
on the site was available, but anecdotal information suggests that municipal waste
generated from the Municipality of Vieques as well as from nearby US Navy installations was
disposed at the site. GPS measurements taken at the site indicated site elevations ranging
from 3.9 m to 7.7 m. Figure 0-15 shows an aerial photograph of the site and the inferred
waste limits as estimated from anecdotal information provided by those assisting the project
team at the site and the conditions encountered in the field.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Approximate
Waste Limit
Figure 0-15. Aerial Photograph of the Closed Vieques Landfill and Approximate Waste
Boundary
Field Observation Results
The field team visited the closed Vieques Landfill on 29 March 2011 on an 84 °F day with
scattered cloud cover and moderate winds (Wunderground 2011b). Vieques Island was
accessed by taking a passenger ferry from Fajardo and the project team was escorted to the
site by Mr. Danny Rodriguez (US EPA Caribbean Division) and Mr. William Cruz (Municipality
of Vieques). Ms. Myrna Rfos of JCA also accompanied the project team to the site.
The site was elevated from the adjacent beach. A chain link fence was found around most
of the site; barbed wire fence was found along the northern slope adjacent to the beach.
Much of the fence line had been torn down or was sagging (Figure 3-16). The facility's main
entrance did not have a locking gate - at the time of the field visit a 3-ft high soil berm was
in place to prevent vehicle access. A large sign at the entrance provided the name of the
landfill and indicated that the site was closed.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Figure 0-16. Sagging Fence at the Closed Vieques Landfill
The landfill was mostly flat and predominantly level. The northern slope could not be
accessed so it is unknown whether this portion of the landfill had a gradual or steep slope.
A small herd of horses was grazing within the landfill's limits along with several trails (Figure
3-17), small pits that appeared to be dug by an animals (or humans to collect water for
animals) as well as manure were found throughout the site. No leachate seeps were visible
at the site.
Vegetation consisting of grasses, shrubs, and trees was present throughout the site but was
not uniform in appearance and much of the vegetation appeared to be dead or dying (note
that less than 0.5 in. of rain fell in the month precedingthe site visit (Wunderground 2011b)).
Isolated areas of the landfill surface showed evidence of previous, small fires at the site. It
was unclear whether or not the fires were set deliberately. A variety of grasses, shrubs, and
small trees were found throughout the site.
The soil at the site was a silty sand based on visual inspection. The cover thickness was
variable throughout the site - exposed waste was present in several areas of the site. The
landfill surface also exhibited minor undulations and surface depressions which following
rainstorms likely hold water. Additionally, various pieces of debris were present in small
amounts throughout the site, though it was not clear whether this material was deposited
at the site before or after the landfill ceased operations. No objectionable odors or vectors
were apparent at the site.
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Figure 0-17. Herd of Horses Grazing at the Closed Vieques Landfill
Figure 0-18. Recent Waste Deposits at the Closed Vieques Landfill
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
No groundwater monitoring, subsurface gas monitoring, stormwater control, or leachate
control systems were observed at the site.
Field Measurement Results
Figure 3-19 shows the approximate SEM path followed (solid red line) and the location of
the Guelph Permeameter test performed at the Vieques Landfill (yellow dot).
During surface emissions monitoring, methane was detected on a limited basis. A few
detections greater than background readings were measured, but no measured
concentration exceeded 10 ppm during the sampling period. Since access to the north edge
of the landfill was limited, methane surface emission readings were limited to the top deck
of the landfill.
The data collected with the Guelph Permeameter was used to calculate a hydraulic
conductivity of 9.0 x 10"5 cm/s. Additional details on the calculation of the hydraulic
conductivity of the cover soil at the site are provided in Appendix E.
Figure 0-19. Surface Emissions Monitoring Path and Guelph Permeameter Test
Location at the Closed Vieques Landfill, Vieques, Puerto Rico
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Discussion and Recommendations
Discussion
RCRA Subtitle D and the Puerto Rico Non-Hazardous Solid Waste Management rules require
MSW landfills to be closed in a manner that minimizes the impact on human health and the
environment and return the land to beneficial reuse. The regulations aim to reduce the
transport of potentially harmful gases and liquid contaminants beyond the perimeter of the
site and to physically stabilize the landfill.
Table 4-1 lists the metrics used to evaluate each site and the result of the observation of
each metric for each site. The criteria can be broadly classified in five major categories:
Access Control,
Environmental Monitoring and Control Systems,
Maintenance,
Waste Mass Stability, and
Final Cover
Each criterion is described further in the following sections.
Table 0-1. Summary of Visual Assessment Criteria
Criterion
Rincon 1
Rincon 2
Cabo Rojo
Vieques
Access Control
Complete Accessibility
Fence
Gate
Lock
Recently-Placed Waste
Signage
Non-Vector Animals
No
Partial1
Yes
NA
Yes
Yes
No
No
No
No
No
Yes
No
No
No
Yes1
Yes
Yes
No
Yes
No
No
Partial
No
No
Yes
Yes
Yes
Environmental Monitoring and Control Systems
Groundwater Monitoring
Wells
Subsurface Gas Monitoring
Probes
Leachate Control
Stormwater Control
Yes2
Yes2
No
No
No
No
No
No
No
No
No
Yes3
No
No
No
No
Maintenance
Exposed Waste
Leachate seeps
Vegetation
Odor
No
No1
Inadequate4
No
Yes
Yes
Inadequate
Yes
Yes
No1
Overgrown
No
Yes
No1
Inadequate5
No
Discussions and Recommendations
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Criterion
Vectors
Rincon 1
No
Rincon 2
Yes6
Cabo Rojo
No
Vieques
No
Waste Mass Stability
Potential unstable slopes7
Yes
Yes
Yes
NA1
Final Cover
Hydraulic conductivity < 10~5
cm/sec
NM
No
Yes
No
NA = Not available NM = Not measured
1 The criterion was not assessed for the entire landfill since some portions of the site were inaccessible.
2. Historical documents confirm that wells were installed at the site; however, the project team did not
witness them while in the field.
3 A ditch parallel to the main road was adjacent to the landfill; however, it is not clear if the ditch was
intentionally constructed as part of landfill closure or for stormwater conveyance as part of the road
construction, or if the ditch had formed naturally.
4 Large areas (on the order of acres) of the Rincon Municipal Landfill lacked vegetative cover.
5 Vegetation was difficult to assess as a result of an ongoing drought in the region. Some areas exhibited
dense vegetative growth; however, many areas of the landfill held sparse vegetation, and the earthen cover
was more prominent.
6 Flies were present throughout the site.
7 Slope stability was assessed based on visual observations in the field regarding the steepness of the slopes
and other environmental factors (e.g. contact of tides with slopes).
/Access Control
Preventing public access to closed landfills helps to secure closed landfill sites from
unauthorized access. 40 CFR 258.25 requires all MSW landfill units to prevent public
access, vehicular traffic, and illegal dumping through the use of artificial and/or natural
barriers. Fences, gates, and locks all contribute to preventing unauthorized dumping,
scavenging, or other illicit activities.
Fences can also prevent site access by animals and other livestock. Free-roaming livestock
and other animals are prevalent in many parts of Puerto Rico. Allowing free-grazing animals
at closed landfills can potentially lead to damage to cover systems or environmental
monitoring and control systems. For example, at the Vieques Landfill, minor undulations in
the cover appeared to have been created by the horses grazing on the landfill. Given that
final covers are constructed, in part, to minimize infiltration of precipitation, such
depressions can promote water retention thereby increasing the potential for leachate
generation. Livestock manure may also attract vectors.
Environmental Monitoring and Control Systems
Groundwater and gas monitoring systems are useful for evaluating the impact of a landfill
site on human health and the environment as part of long-term care activities. With the
exception of Rincon 1, no facilities appeared to have any environmental monitoring
systems in place (note that presence of groundwater wells at Rincon 1 were reported in
Discussions and Recommendations
32
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
historical documentation but were not observed by the field team during the site visit
since knowledge of these wells came after the site visits were completed). No gas or
groundwater monitoring data was available for review from any of the visited sites.
Environmental control systems also play an important role in maintaining the integrity of
a closure system. No facilities were found to have leachate control or stormwater control
systems. Stormwater control infrastructure prevents the loss of final cover soil via
erosion, controls and directs runoff to appropriate management areas, and can reduce
failure of final cover systems by reducing erosive forces. Stormwater control systems also
reduce the potential volume of leachate generated by minimizing percolation of rainfall
into the waste mass. Several of the facilities had large, relatively flat areas which did not
appear to route stormwater away from the waste mass, but rather appeared to promote
surface ponding.
Historical documents suggest that JCA required Cabo Rojo and Rincon 1 to install leachate
control systems. The circumstances surrounding the requirement to install such systems
are unknown. The presence of leachate seeps on the side slopes at both sites could not
be evaluated because of steep slopes and heavy vegetation.
Historical documents indicate that Cabo Rojo had also been instructed to install a system to
vent gases from the landfill. The details surrounding the request to install a gas venting
system are unclear. No evidence of a gas venting system was seen during the site visit. A
June 1996 closure inspection report by JCA indicated that nine gas monitoring wells had
been installed. Although the locations of these wells were not shown in a plan view, they
appeared to be installed near the edge of the waste and mostly on the top deck of the
landfill. No evidence of these wells was observed during the site visits.
Maintenance
Routine monitoring and maintenance of the cover, vegetative growth, access control
infrastructure, and environmental monitoring and control infrastructure is required to
ensure the integrity of the closure system at MSW landfills. The Cabo Rojo Municipal
Landfill, the Vieques Landfill, and Rincon 1 each, to some degree, appeared to require
mowing or other forms of vegetation maintenance. At Cabo Rojo, three of the four side
slopes were overgrown which contributed to the inaccessibility of the site. Similarly, at
Rincon 1, vegetation along the north slope (in conjunction with steep slopes) made access
to the north slope unsafe.
Fences should be maintained to prevent public access. At Vieques, the fence on the north
side of the site was found to be sagging (as illustrated in Figure 3-16) or completely down
in some instances. Maintenance of access roads and vegetative growth also facilitates
access to monitoring infrastructure, where present. Historical documents for Rincon 1
indicate that maintenance of the existing groundwater wells was previously requested in
an inspection report.
Maintenance of the final cover system also prevents rainwater percolation to the waste layer
and minimizes odors and vector attraction. Exposed waste was found at Vieques, Cabo Rojo,
Rincon 1, and Rincon 2.
Discussions and Recommendations 33
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
Waste Mass Stability
Waste mass stability was visually evaluated at each site—the field team looked for steep
slopes, evidence of side slope failure, and other factors that may affect the stability of the
waste mass. No evidence of previous slope failure was witnessed while in the field, though
it is noted that the majority of the toe of the slope at two of the sites (Rincon 1, Cabo
Rojo) as well as the northern slope face at Vieques, was not accessible. Furthermore,
heavy vegetation in some areas precluded accurate identification of slope failure. A
closure inspection report for one of the sites (Cabo Rojo) indicated that some form of
slope stabilization had been conducted as part of closure activities, but further details
were not available. Steep slopes (greater than the standard 3 horizontal to 1 vertical for
above-grade landfill slopes) were present at all four sites that were visited.
Other factors were observed in the field that may contribute to long-term waste mass
instability. For instance, the proximity of Rincon 2 leaves it subject to the rising and falling
tides of the Caribbean Sea. Exposed waste on the western edge of Rincon 2 was in direct
contact with the sea during the site visit. A coastline recession study conducted by the USGS
in 2007 suggests that the shoreline in this area has recessed at a rate of 1.1 m/yr. Thus, it is
likely that a potentially substantial portion of the landfill has already been washed away into
the sea, and projections from the USGS (2007) report suggest the shoreline (and thus the
western boundary of the landfill) will continue eroding absent of shoreline stabilization
measures. Although a shoreline analysis in Vieques similar to that of Rincon was not
available, the northern edge of the Vieques Landfill was located nearthe shoreline and could
be subject to similar tidal contact and influence.
Final Cover
The final cover system of a closed landfill plays a critical role in reducing the
environmental impact of the site. Chapter 40 CFR 258.60(a) and Puerto Rico Non-
Hazardous Solid Waste Management Rule 565(A) requires that the permeability of the
final cover soil be less than or equal to the permeability of any bottom liner system or
natural subsoils present or less than or equal to 1 x 10~5 cm/sec, whichever is less.
Furthermore, the regulations each require that a 6-in erosion layer of earthen material
capable of supporting vegetative growth be placed over an 18-in infiltration layer of
compacted earthen material that meets the permeability requirement.
During the field experimentation, a single hydraulic conductivity measurement was taken
on location at three sites. The intent of these measurements was to conduct a fairly rapid
field measurement for comparison to the regulatory metric - results of a single
measurement cannot be extrapolated across the entire landfill, but can provide an
indication whether site soils present may include some areas with (or without) a low-
permeability layer.
The permeameter apparatus and experimental procedure has limitations in that the one-
head test method (used at all three sites) is accurate between 10"2 to 10"5 cm/sec and only
within a factor of two. Because the hydraulic conductivity was calculated from the data
collected in the field, selecting different values for variables in the equations (e.g. values
Discussions and Recommendations 34
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
corresponding to the soil classification according to the user's manual) can have an impact
on the calculated result. Detailed information on hydraulic conductivity would require a
more robust field and/or laboratory sampling and analysis protocol which was beyond
the scope of this study.
The hydraulic conductivity measured in the cover soil at the Cabo Rojo Municipal Landfill
was less than that required in the regulations (i.e., hydraulic conductivity was less than
10~5 cm/sec). The measured hydraulic conductivity at Rincon 2 and Vieques was greater
than that required in the regulations (i.e., hydraulic conductivity was greater than 10~5
cm/sec).
Recommendations
The intent of this study was to evaluate a subset of closed landfills in Puerto Rico to help
guide decision-making for future MSW landfill closures on the island. During the field
effort, a single measurement of the hydraulic conductivity of the final cover was taken at
three sites and no environmental monitoring data were available to assist in the
evaluation of the performance of the closure systems. Additionally, the inaccessibility of
some areas at each site leaves some questions unanswered (e.g. presence of leachate
seeps and slope failures). Notwithstanding the limitations of this study, the following
sections discuss recommendations for future closures as well as recommendations for
further study to help improve future closures.
Recommendations to Further Investigate Targeted Sites
The following recommendations are offered to further investigate the targeted closed
landfills from this study. Broader recommendations that cover all closed landfills (and, in
some cases, operating landfills that may be closed in the future) are provided in Section
4.2.2.
More Detailed Final Cover Analysis. Additional hydraulic conductivity analysis in soil
covers would provide a more expansive data set so that stronger conclusions can be
drawn regarding the apparent conformance of final cover installations to applicable
regulations can be made. Furthermore, an evaluation of in-place soil thicknesses (to
assess whether the regulatory-required 18-inch clay layer and 6-inch thick vegetative
layer is present) may provide further understanding of the presence of conforming final
covers.
Groundwater Evaluation. The groundwater quality at each of the targeted sites is
unknown - only one of the four sites apparently had groundwater monitoring wells
installed and of those two wells, two were reportedly "dry" based on a JCA inspection of
the site. An assessment of groundwater quality upgradient and downgradient of each site
(by taking grab samples in temporary wells (installed using a direct-push technology rig)
may provide a valuable snapshot indicating potential groundwater impacts and whether
additional assessment may be warranted. Analysis of field parameters (pH, temperature,
dissolved oxygen, oxidation reduction potential) and laboratory parameters for collected
samples (e.g., those listed in Appendix I to 40 CFR 258) would provide a substantial insight
into each landfill's environmental impact. More detailed planning would be required to
Discussions and Recommendations 35
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
ensure samples collected were representative of groundwater conditions and
appropriately captured potential landfill impacts - as described earlier, the complex
configuration of some of the sites (e.g., Rincon 2 situated between the sea and a
wastewater drainage ditch) may not make access or accurate assessment feasible.
Landfill Gas Migration Monitoring. Although methane surface emissions were evaluated
at each site during this investigation, landfill gas generated within landfills tends to
migrate along the path of least resistance which may not necessarily be through the top
cap. Assessment of gas migration via monitoring probes at the target sites could provide
information regarding landfill gas producing activity within the site and help characterize
potential risk to nearby receptors. Similar to that described above with groundwater
monitoring, the complex configuration of the targeted sites necessitates additional, more
detailed planning to ensure that any gas migration assessment would be captured by
traditional means such as screened PVC wells around the landfill perimeter. Perimeter
landfill gas monitoring may be supplemented by assessing landfill gas production or
concentrations within the waste itself.
Assessment of Beneficial Use and/or Remedial Opportunities. Each of the sites visited in
this study had limited or no ongoing beneficial uses (e.g., recreation areas, etc.). Although
assessing potential environmental impacts further is warranted, a concurrent evaluation
of potential beneficial uses could serve the purpose of mitigating environmental impacts
while creating useful space or a useful asset out of each of the landfills. Beneficial use
opportunities could include implementation of a renewable energy project (e.g., solar
panels or landfill gas beneficial use), or redevelopment of the site for public use.
Remedial opportunities should only be explored after environmental risks to
groundwater, surrounding site soils, and air have been properly characterized. Following
characterization, potential remedial opportunities can be identified. Low-cost, low-
maintenance opportunities should be primary considerations. Given the apparent lack of
covers seen at each site, one of the targeted sites may be a candidate to explore
implement an evapotranspiration cover. An evaluation of evapotranspiration covers by
the US EPA suggested that several areas within the Mayaguez and San German eco-zones
(which includes Rincon and Cabo Rojo) could feasibly implement an evapotranspiration
cover based on literature-reported values. A site-specific design and performance
evaluation would help guide decision-making in this respect to reveal whether or not
technical and economic feasibility of this technology would exist for the target sites.
Recommendations for Future Closures
Install and maintain access control infrastructure at all MSW landfills. Access control is
important to help preserve the integrity of a closed landfill. Fences, gates, and locks
should be installed and used where natural barriers do not already reasonably prevent
access. These barriers help to prevent scavenging, illegal dumping, and unwanted
habitation by local livestock.
Install and maintain the minimum-required final cover or consider alternative,
performance-based final cover systems. All sites should be closed in accordance with 40
Discussions and Recommendations 36
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
CFR 258.60(a) and Puerto Rico Non-Hazardous Solid Waste Management rules which
require an 18-in infiltration layer of earthen material and a 6-in erosion layer of earthen
material capable of supporting vegetative growth. The minimum permeability of the
cover should be less than or equal to 1 x 10~5 cm/sec in cases where a bottom liner system
is not present.
Alternative, performance-based final cover systems (such as those that rely on
evapotranspiration principles) may be appropriate in certain areas of Puerto Rico. Since
some landfills in Puerto Rico recently have been expanded to include bottom liner
systems (thus resulting in a potentially more stringent final cover requirement based on
a direct interpretation of RCRA), the importance of evaluating appropriate final cover
options that are effective and can feasibly be implemented increases going forward. We
recommend the implementation of a test site at a landfill located in one of the eco-zones
that were identified as potentially compatible with an evapotranspiration cover in a
companion project that was conducted in Puerto Rico in 2010 by US EPA ORD titled
Screening Tool for Assessing Feasibility of ET Covers for Landfills in Puerto Rico.
Design and construct above-grade side slopes to a maximum 3:1 (H:V). Steep slopes may
pose long-term stability issues and may make access during routine post-closure
monitoring difficult. Standard landfill engineering practice is to grade side slopes to a
maximum 3 horizontal to 1 vertical, though site-specific geotechnical considerations must
be considered as part of any closure design. Slope stability of existing landfills should be
evaluated on a case-by-case basis, and remedial actions including re-grading and slope
stabilization efforts should be pursued where necessary.
Design and install stormwater management infrastructure. Stormwater benches,
swales, and downchutes will help encourage run-off and prevent damage to the final
cover at closed landfills. Unmanaged stormwater can have a detrimental effect to the
longevity of a closed landfill. The need for stormwater retention ponds in a stormwater
management system should be evaluted on a case by case basis. Additionally, each facility
should apply for appropriate permits for discharging stormwater.
Maintain existing gas collection infrastructure. At sites where gas collection and control
systems have been installed, the systems should be operated and maintained in
accordance with Operational Standards for Collection and Control Systems (40 CFR
60.753). Annual reports should be submitted in accordance with 40 CFR 60.757(f).
Routine monitoring requirements in the regulations are stringent and include operating
parameters that can change fairly rapidly - effective design, construction quality
assurance, and operations monitoring is necessary for future closed facilities with gas
collection systems to remain in compliance.
Monitor groundwater and perimeter gas. A groundwater monitoring system should be
installed and utilized in accordance with 40 CFR 258 Subpart E. Explosive gas monitoring
should be conducted in accordance with 40 CFR 258.23.
Construction and Long-term Maintenance of Leachate Collection Systems. According to
40 CFR 258.61(a)(2), during the post-closure care period, leachate collection systems
Discussions and Recommendations 37
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
employed at each site must be operated to maintain a liquid head of 30 cm or less above
the liner in accordance with 40 CFR 258.40. Though none of the facilities targeted in this
study had leachate collection systems, a handful of facilities on the island have installed
one or more lined cells with leachate collection. Monitoring and maintenance of leachate
collection systems (as well as overall leachate treatment) is required for closed landfills
with such systems in place. In addition to leachate collection systems associated with
bottom liners, leachate interception systems may be applicable as part of closure for
future facilities to ensure migration of leachate from unlined areas does not occur beyond
the landfill footprint.
Limited information is available regarding the quality of leachate that is collected at active
landfill sites in Puerto Rico, as well as leachate quality at sites that are closed (i.e., seeps).
A comprehensive assessment of leachate quality and management practices would be
greatly beneficial for Puerto Rico environmental regulators and landfill owners/operators.
Given the limited experience on the island with leachate management, such a study could
help provide guidance on effective leachate management techniques that are compatible
with the specific challenges in Puerto Rico (e.g., climatic conditions, typical cover soil
application practices, availability and proximity of wastewater treatment facilities).
Assessment of Beneficial Use Options for Other Closed Landfills or Landfills that will be
Closed in the Near Future. A feasibility assessment of potential beneficial uses of closed
or soon-to-be closed landfills may provide relevant information to local regulatory
agencies and landfill owners and operators. Beneficial uses would likely focus on
redevelopment opportunities for landfills or integration of renewable energy (such as
solar panels or landfill gas-to-energy).
Discussions and Recommendations 38
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An Evaluation and Analysis of Past Landfill Closures in Puerto Rico as Guidance for Current and Future Closures
References
Garcia, Cabot, & Asociados (1994). Closure Plan for the Rincon Municipal Landfill, Rincon
Puerto Rico.
JCA (1996a). Closure Inspection Report for the Rincon Municipal Landfill. 30 July 1996.
JCA (1996b). Correspondence with Municipality of Cabo Rojo. 27 September 1996.
JCA (1996c). Correspondence with Municipality of Cabo Rojo. 23 October 1996.
JCA (1996d). Correspondence with Municipality of Rincon. 10 December 1996.
JCA (1996e). Correspondence with Municipality of Cabo Rojo. 19 December 1996.
JCA (1997a). Correspondence with Municipality of Cabo Rojo. 7 April 1997.
JCA (1997b). Correspondence with Municipality of Cabo Rojo. 19 May 1997.
JCA (1997c). Correspondence with Municipality of Cabo Rojo. 18 June 1997.
JCA (1999). Correspondence with Municipality of Cabo Rojo. 27 September 1999.
JCA (2002). Correspondence with Muncipality of Rincon. 19 March 2002.
Jordan, Jones, Goulding (1994). Cabo Rojo Municipal Landfill Closure Plan. Cabo Rojo,
Puerto Rico.
Municipality of Cabo Rojo (2000). Correspondence with the Junta de Calidad Ambiental.
17 March 2000.
US FWS (2009). Old Landfill, Rincon, Puerto Rico. Personal communication from Edwin
Muniz, Field Supervisor of US Fish and Wildlife Services to Patrick Durack, Deputy
Director of US EPA Region 2. No date on correspondence but the correspondence
references an 11 June 2009 site inspection.
USGS (2007). Historical Shoreline Changes at Rincon, Puerto Rico, 1936-2006. Open File
Report 2007-0107.
Wunderground (2011a). Weather History for Mayaguez, Puerto Rico on March 28, 2011.
Accessed 12 April 2011.
.
Wunderground (2011b). Weather History for Roosevelt Roads, Puerto Rico on March 29,
2011. Accessed 12 April 2011. <
http://www.wunderground.eom/history/airport/TJNR/2011/3/29/DailyHistory.html7req
_city=NA&req_state=NA&req_statename=NA>.
References 39
-------
Appendix A- USGS Quadrangle Maps and Approximate Site Boundaries
W ;-^
, ./•/••• -^
m
! JE
^^ . '•£*&. • , f •
»
Legend
Approximate Site
Boundary
5DO 1C03
'•<•-}-
Appendix Hgure A-l
Kincan Municipal Landfill
USGS (196G)
Source: U.SGeological Survey, Denver, CO, and Department
of Transportation and Public Works, San Juan, PR
Appendix A
-------
fe*> '&> ^
^ . -> Of,\vV^
legend
Approximate Site
Boundary
500 ICO3
ft
N
Appendix l-igure A-2
Closed Rlncon Landfill
Source: U.£ Geological Survey, Denver, CO, and Department
of 1 raimportation and Public Works, San Juan, PR
Appendix A
-------
t^'^-f'r^^^^y^^^^!^'^^^^w^^>/^-^:'-^ "* ' '-I
^VSr&S^'^rFM&tf™^^^ SftWwstAL^.Sirjs.. /'
'--, I
K. }
^O2lS&fi«w%tt(
:•& yffi ^Saii&jg
^S4^fe •*j
1 a •^If^i -, -J-rft B ». ^ 'I '
'B--^>;i%%v
SWi
^r^j^W
Approximate Site
Boundary
500 10OG
ft
Appendix l-igurc A-3
Cabo Rojo Landfill
USGS(1966)
Source: U.SGeolcBicdl Survey, Washingtun, O.C., and Depart-
ment of Transportation and Public Works, San Juan, PR
Appendix A
-------
Legend
Approximate Site
Boundary
10CO
2030
+
Appendix Hgure A-4
Vieques Landfill
USGS (19S1J
Source: U.S Geological Survey, Denver, CO, and Department
of 1 ra importation and Public Warts, San Juan, PR
Appendix A
-------
Appendix B - Supplemental Photographs
Photo #: Rincon Landfill 1-1
View to the east and the southern edge of the site
Photo #: Rincon Landfill 1-2
View to the north- northeast. Pile of mulch shown in the mid-ground.
Appendix B 1
-------
Photo #: Rincon Landfill 1-3
Unknown building near the site entrance
Photo #: Rincon Landfill 1-4
Stockpile of plastic bottles at the southern edge of the site
Appendix B
-------
Photo #: Rincon Landfill 1-5
Photo #: Rincon Landfill 1-6
Description
Close-up view of
ground mulch which
was placed on much
of the site's surface
Description
View of slope on the
edge of the property
Appendix B
-------
Photo #: Rincon Landfill 1-7
Photo #: Rincon Landfill 1-8
Description
View of vegetative
debris and bags with
municipal waste
towards the northern
portion of the site.
Visual inspection of
the bags suggested
they were placed at
the site in the past
few years.
Description
View downslope
towards the eastern
portion of the site
Appendix B
-------
Photo ft: Rincon Landfill 1-9
Photo ft: Rincon Landfill 1-10
Stockpile of intact
and broken cathode
ray tubes that were
placed in a trailer
Description
Description
Tank that was present
on the southern
portion of the site.
The use and contents
of the tank could not
be determined during
the site visit.
Appendix B
-------
Photo #: Rincon Landfill 1-11
Enclosures at plant
nursery on site
Photo #: Rincon Landfill 1-12
Mobile equipment
staged on site.
Appendix B
-------
Photo #: Rincon Landfill 1-13
Description
Municipality
collection vehicle that
arrived to pick up the
plastic bottles from
the stockpile.
Appendix B 7
-------
Photo #: Rincon Landfill 2-1
Photo #: Rincon Landfill 2-2
Description
View of the western
portion of the site.
Description
View of rocks placed
near the coast.
Anecdotal
information from
nearby residents
suggested that the
rocks were placed
thereto reduce
erosion of the shore.
Appendix B 8
-------
Photo #: Rincon Landfill 2-3
View near the site
entrance, where
varying amounts of
municipal waste were
found.
Photo #: Rincon Landfill 2-4
View of the borehole
and the bottom of
the Guelph
permeameter.
Appendix B 9
-------
Photo #: Rincon Landfill 2-5
View of the western
edge of the site,
where debris
appeared to be
contacting the ocean
and washing into the
ocean.
Description
Photo #: Rincon Landfill 2-6
Description
View of stream on
eastern portion of the
site. Cans, bottles,
and other debris were
found to be placed
adjacent to and in the
stream.
Appendix B 10
-------
Photo #: Rincon Landfill 2-7
Photo #: Rincon Landfill 2-8
Description
View of the stream
on the eastern
portion of the site.
Description
A fence running along
a portion of the site.
Appendix B 11
-------
Photo #: Rincon Landfill 2-9
Photo #: Rincon Landfill 2-10
Close-up of wall on
the western portion of
the site. Municipal
waste (mostly
consisting of metal,
plastic, and glass
containers) could be
seen at varying depths
along the wall.
Description
Description
View to the north on
the western portion
of the site. The wall
on the right side of
the photo was
approximately 3 to 4
ft deep. Small pieces
of municipal waste
and other debris can
be seen along the
wall.
Appendix B 12
-------
Photo #: Rincon Landfill 2-11
A view farther south
of photo 2-11. Debris
can be seen in the
cross-section of the
wall.
Appendix B 13
-------
Photo #: Cabo Rojo Landfill 1
Description
Photo #: Cabo Rojo Landfill 2
View to the west,
upslope. Photo taken
near the facility's
gated entrance.
Description
View of the eastern
slope of the landfill.
Appendix B 14
-------
Photo #: Cabo Rojo Landfill 3
Photo #: Cabo Rojo Landfill 4
Description
Vegetation towards
the edge of the top
deck of the landfill.
Description
View of a low-lying
wetland area that
appeared to be
outside of the landfill
footprint to the
northwest.
Appendix B 15
-------
Photo #: Cabo Rojo Landfill 5
Description
View from the top of
the landfill looking to
the northwest.
Photo #: Cabo Rojo Landfill 6
Description
Appendix B 16
-------
Photo #: Cabo Rojo Landfill 7
Photo #: Cabo Rojo Landfill 8
Description
Filling the water jug
used for hydraulic
conductivity testing.
Description
View to the south
from the top deck of
the landfill.
Appendix B 17
-------
Photo #: Cabo Rojo Landfill 9
View of an apparent
property boundary
marker towards the
south side of the
landfill.
Photo #: Cabo Rojo Landfill 10
Description
Description
View of borehole
prior to hydraulic
conductivity testing.
Appendix B 18
-------
Photo #: Cabo Rojo Landfill 11
Description
Close-up view of
clayey cover
excavated as part of
borehole
advancement for
hydraulic
conductivity testing.
Appendix B 19
-------
Photo #: Vieques Landfill 1
Photo #: Vieques Landfill 2
Photo of facility sign
indicating that the
site is closed.
Description
Description
View of the landfill
top deck.
Appendix B 20
-------
Photo #: Vieques Landfill 3
Description
View of the landfill
top deck.
Accumulation of
debris in the
midground.
Photo #: Vieques Landfill 4
Description
Top deck of the
landfill.
V
Appendix B 21
-------
Photo #: Vieques Landfill 5
Photo #: Vieques Landfill 6
Description
View of slight surface
depression. It
appeared that some
animals had gathered
in the area based on
the presence of hoof
prints.
Description
Presence of visible
debris on the landfill
surface.
Appendix B 22
-------
Photo #: Vieques Landfill 7
Description
View of the landfill to
the north. Heavy
vegetation was
present along the
northern and western
borders of the site.
Photo #: Vieques Landfill 8
Description
View towards the
north of the landfill.
The beach was not
accessed during the
field visit to assess
whether the northern
edge of waste could
be seen.
Appendix B 23
-------
Photo #: Vieques Landfill 9
Photo #: Vieques Landfill 10
View of the facility
entrance. The south
portion of the site
abutted a paved road.
The facility's entrance
did not have a gate or
a lock. An earth berm
approximately two ft
high was in place to
limit access.
Description
Description
View of the southern
edge of the site from
the paved access
road.
Appendix B 24
-------
Photo #: Vieques Landfill 11
Photo ft: Vieques Landfill 12
Description
Description
Close-up view of the
cover soil at the site.
Appendix B 25
-------
Photo #: Vieques Landfill 13
Description
-..<"#•••,.•.
View of a path that
was worn towards
the edge of the site.
Several similar paths
were seen
throughout the site
and appeared to be
from the roaming of
the horses.
Photo #: Vieques Landfill 14
Description
Evidence of a small,
controlled burn on
the landfill surface.
Appendix B 26
-------
Appendix C - Rincon Landfill Hydraulic Conductivity
INNOVATIVE WASTE CONSULTING SERVICES, LLC
6628 NW 9th Blvd., Suite 3, Gainesville, FL 32605, USA
APPENDIX C-Field Saturated Hydraulic Conductivity of Cover Soil at
Rincon 2
ENGINEER: Brett Tooley
DATE:
4/5/2011
PROJECT NAME: Puerto Rico Landfill Closure Evaluation
CHECKED BY: Jon Powell
DATE:
4/8/2011
SUBJECT: This calculation package provides the calculation of the field saturated hydraulic conductivity of the
cover soil at Rincon 2 in Rincon, Puerto Rico, using field data collected with a Guelph Permeameter.
DESIGN CRITERIA AND APPROACH;
The methodology provided with the Model 2800K1 Guelph Permeameter (SoilMoisture Equipment Corp
2005) was used to calculate a steady-state rate of change value in the field, then using a series of constants
and assumptions with the field data to calculate the hydraulic conductivity.
First, the top 2 to 3 inches of soil were removed using a hand auger. Following initial removal of the topsoil
layer, the soil beneath was visually classified. The cover soil at the landfill was classified in accordance with
the guidelines provided with the field equipment. A a* value was assigned to the soil under evaluation,
where a* is the macroscopic capillary length parameter which represents the ratio of gravity to capillary
forces during infiltration or drainage.
For the closed Rincon Landfill,
0.04 cm"
Based on the value of a*, the appropriate C Factor (a numerically-derived shape factor) equation was
selected. The C Factor curve, Cy is used for conditions where a* = 0.04 cm" and is calculated as follows
,••' H/a
where,
l.992
C2 = numerically-derived shape factor (dimensionless)
H = height of water in the well (cm)
a = well radius (cm) (always equals 3.0 cm for standardized procedure)
In the field, the steady-state rate of fall ( Rlss) was measured using the graduated cylinder in the Guelph
Permeameter. Readings (RJ were taken until the measurements stabilized (minimum 3 consecutive
readings of equal value). Rlss is calculated from measurements taken on the graduated cyclinder of the
Guelph Permeameter as follows:
where,
R!= the stabilized water level change (cm)
T= time interval between readings (sec)
Appendix C
-------
INNOVATIVE WASTE CONSULTING SERVICES, LLC
6628 NW 9th Blvd., Suite 3, Gainesville,
APPENDIX C -Field Saturated Hydraulic Conductivity of Cover Soil
at Rincon 2
PROJECT NAME: Puerto Rico Landfill Closure Evaluation
The flow rate is calculated fr
The value, X, represents the
value is typically used at site
is the cross-sectional area of
expected to be relatively low
procedure (thus the X value)
The field saturated hydraulic
i
CALCULATIONS:
Calculating the C ^
H =
a =
C2= 0.8
Calculating the Flc
Table ]
Note that the elap
taken at 2 minute
R1= 0.50
T= 120
FL 32605, USA
ENGINEER: Brett Tooley D
CHECKED
BY: Jon Powell D
ATE: 4/5/2011
ATE: 4/8/2011
Dm Rlss as follows:
-------
INNOVATIVE WASTE CONSULTING SERVICES, LLC
6628 NW 9th Blvd., Suite 3, Gainesville, FL 32605, USA
APPENDIX C-Field Saturated Hydraulic Conductivity of Cover Soil at
Rincon 2
ENGINEER: Brett Tooley
DATE:
4/5/2011
PROJECT NAME: Puerto Rico Landfill Closure Evaluation
CHECKED BY: Jon Powell
DATE:
4/8/2011
RISS= 4.17E-03 cm/sec
X= 35.22
cm
Qi = 0.147 cm3/sec
Calculating the hydraulic conductivity, K fs:
Kfc= 1.3E-04 cm/sec
CONCLUSION:
The calculated field saturated hydraulic conductivity of the cover soil at Rincon 2 was 1.3 x 10 cm/sec.
REFERENCES:
SoilMoisture Equipment Corp (2005). Model 2800K1 Guelph Permeameter Operating Instructions.
Santa Barbara, CA.
Appendix
1
-------
Appendix D - Cabo Rojo Landfill Hydraulic Conductivity
INNOVATIVE WASTE CONSULTING SERVICES, LLC
6628NW 9th Bivd. Suite 3, Gainesville. FL 32605, USA
APPENDIX D ^lew SatyratedHydraulicConduciMtvotCaverSon
for Cabo Rojo Landfil I
ENGINEER: Brett Tooigy
DATE: 4/S/2O11
PROJECT NAME: Puerto Rico Landfill Closure Evaluation
CHECKED 8¥: Jon Powell
DATE: 4/8/2011
SUBJECT: This calculation package provides the calculation of the field saturated hydraulic conductivity of the
cover sol at the dosed Cabo Rojo Landfill in Cabo Rojo, Puerto Rico, using fiefd data collected using a Guelph
Ptrmeamtter.
DESIGN CRITERIA AND APPROACH;
The methodology provided with the Model 2SOOK1 Guelph Perm ea meter {SoilMoisture Equipment Corp
2005) was used- to calculate a steady-state rate of change value in the field, then using a series of constants
and assumptions with the field data to cafculate the hydraulic conductivity.
First, the top 3 or 4 inches of soil were removed using a hand auger. Following initial removal of the tops-oil
layer, the soil beneath was visually classified., The cover soil at the landfill was classified in accordance with
the guidelines provided with the field equipment. A Q* value was assigned to the soil under evaluation,
where a* is the macroscopic capillary length parameter which represents the ratio of gravity to capillary
forces during infiltration or drainage.
For the closed Cabo Rop Landfill
a* = 0.01 cm"1
Based on the value of a", the appropriate C Factor {a numerically-derived shape factor) equation was
selected. The C Factor curve, C ? is used for conditions where a* = 0.01 crrf1 and is calculated as follows:
/ °*?-
€j " '
,2.031 +0.l21(W/
where, Cs = numerically-derived shape factor (dimension less)
H = height of water in the well (cm)
a = well radius (cm) (always equils 3.0 cm for standardized procedure)
in the field, the steady-state rate of fall ( R^ } was measured using the graduated cylinder in the Guelph
Per mea meter , Readings (Rt) were taken until the measurements stabilized (minimum 3 consecutive
readings of equal value). Ru. is calculated from measurements taken on the graduated cylinder of the
Gueiph Permeameter as follows:
where,
Rj= the stabilized water level change (cm)
T - time interval between readings (sec)
Appendix D 1
-------
Innovative Waste Consulting
Services, ILC
for Cabo ftojo Landfill
PROJECT NAME; Puerto Rico Landfill Closure Evdluation
The flow rate is calculated rrorr
The value, X, represents the cros
typically used at sites where the
cross-sectional area of the inner
relatively low), At Cabo Ro|o, th€
used to calculate Q.
The field saturated hydraulic «
K
CALCULAT
Calculating
H ™
a =
C, =
Calculating
•NGINEER: Brett Tooley
;HECKIP BY- Jon Powell
DATE: 1/5/2011
DATE: 4/8/2011
i Rlss as follows;
i-sectional area of the Inner and outer reservoir of the instrument (this value is
ivdraulic conductivity is expected to be relatively high}. The value Y is the
reservoir only (used at sites where the hydraulic condyctivity is expected to be
> inner reservoir was used while taking measurements, thus the V value was
>nductivity (Kfl) of the cover soil at the site is calculated as follows:
2~H.l + 'C-C^ 2-{^-]
QMS;
trie C Factor, C ,~ ;
5 cm
3 cm
Q.SQ9
the Flow Rate, Qt:
Table 1. Field Data
Reading
1
2
3
4
5
6
7
§
9
10
11
12
13
14
Elapsed
Time
(sec)
22
82
142
202
262
322
382
442
502
562
682
862
982
1162
Time
Interval
(sec)
0
60
§0
60
60
60
60
60
60
60
120
180
120
180
• H:c
"' -2.031 +0.12 l-:H-c; '
Water Level
fern)
32.9
38.5
42,9
44,9
47,0
48,2
49.2
50.7
51.4
52.3
54.3
56.3
58.5
59.9
Water Level
Change, R : (cm)
0.0
5.6
4,4
2,0
2,1
1,2
1.0
1.5
0.7
0.9
2.0
2.0
2.2
1.4
"
Rate of Water
Level Change
(cm/s}
O.OOE+00
9.33E-02
7.33E-02
3.33E-02
350E-02
2.00E-02
1.67E-02
2.50E-02
1.17E-02
150E-02
1.67E-02
1.11E-02
1.83E-02
7.78E-03
Continued on Next Page
Appendix D
-------
Innovative Waste Consulting
Services, LiC
E NGtNEER; _ BreMToolei DATE; 4/5/2011
ffiOJECT NAME: Puerto Rico landfill Closure Evaluation CHECKED BY: Jon Powell DATE; 4/8/2011
R,=
T =
Y =
Calculating
CONCLUSH
Continued from Previous Page
15 1342 180 62.1 2.2 1.22E-02
16 1522 180 635 1.4 7.7SE-03
17 1702 180 65A 1.9 1.06E-02
18 1882 180 67.1 1.7 9.44E-03
19 2062 180 68,6 1.5 8.33E-03
20 2242 180 70.1 1.5 8.33 E-03
21 2422 180 71,6 1.5 833E-03
RI
1.50 cm
180 sec
8.33 E-03 cm/sec
2.15 cm2
0,018 cmVsec
the hydraulic c on ducti vity, Kfi: C^Qi
•V«- , , /|f \
4.4E-06 cm/sec
DN;
The calculated field saturated hydraulic conductivity of the cover soil at the closed Cabo Rojo Landfill was
4.4 x 10"* cm/sec,
REFERENCES:
SdlMdssuit EquipmeittCoip (2005), Model 2SOOK1 Guelph Peimeamet«f Operating Instructions. Satta B^bara, CA.
Appendix D
-------
Appendix E - Viegues Landfill Hydraulic Conductivity
INNOVATIVE WASTE CONSULTING SERVICES, LLC
6628 NW 9th Blvd., Suite 3, Gainesville, FL 32605, USA
APPENDIX E -Field Saturated Hydraulic Conductivity of Cover Soil
at the Vieques Landfill
ENGINEER: Brett Tooley
DATE:
4/5/2011
PROJECT NAME: Puerto Rico Landfill Closure Evaluation
CHECKED BY: Jon Powell
DATE:
4/8/2011
SUBJECT: This calculation package provides the calculation of the field saturated hydraulic conductivity of the
cover soil at the closed Vieques Landfill in Vieques, Puerto Rico, using field data collected with a Guelph
Permeameter.
DESIGN CRITERIA AND APPROACH;
The methodology provided with the Model 2800KlGuelph Permeameter (SoilMoisture Equipment Corp
2005) was used to calculate a steady-state rate of change value in the field, then using a series of constants
and assumptions with the field data to calculate the hydraulic conductivity.
First, the top 2 to 3 inches of soil were removed using a hand auger. Following initial removal of the topsoil
layer, the soil beneath was visually classified. The cover soil at the landfill was classified in accordance with
the guidelines provided with the field equipment. A a* value was assigned to the soil under evaluation,
where a* is the macroscopic capillary length para meter which represents the ratio of gravity to capillary
forces during infiltration or drainage.
Forthe closed Vieques Landfill,
a* = 0.04 cm"1
Based on the value of a*, the appropriate C Factor (a numerically-derived shape factor) equation is selected.
The C Factor curve, C^ is used for conditions where a* = 0.04 cm"1 and is calculated as follows:
H/a
.. C <=S3
where,
- V1.992 + 0.091(tf/o)>
C2 = numerically-derived shape factor (dimensionless)
H = height of water in the well (cm)
a = well radius (cm) (always equals 3.0 cm for standardized procedure)
In the field, the steady-state rate of fall ( Rlss) was measured using the graduated cylinder in the Guelph
Permeameter. Readings (RJ were taken until the measurements stabilized (minimum 3 consecutive
readings of equal value). Rlss is calculated from measurements taken on the graduated cylinder of the
Guelph Permeameterasfollows:
where,
R!= the stabilized water level change
(cm) T= time interval between readings (sec)
The flow rate is calculated from R1cc as follows:
Iss
Appendix E 1
-------
INNOVATIVE WASTE CONSULTING SERVICES, LLC
6628 NW 9th Blvd., Suite 3, Gainesville, FL 32605, USA
APPENDIX E-Field Saturated Hydraulic Conductivity of Cover Soil
at the Vieques Landfill
PROJECT NAME: Puerto Rico Landfill Closure Evaluation
ENGINEER: Brett Tooley DATE: 4/5/2011
CHECKED BY: Jon Powell DATE: 4/8/2011
Q! = XR lss or d = YRlss
The value, X, represents the cross-sectional area of the inner and outer reservoir of the instrument
(this value is typically used at sites where the hydraulic conductivity is expected to be relatively high).
The value Y is the cross-sectional area of the inner reservoir only (used at sites where the hydraulic
conductivity is expected to be relatively low). Based on visual classification of the soil at Vieques, the
combined reservoir procedure (thus the X value) was used.
The field saturated hydraulic conducivity (Kfs) of the cover soil atthe site is calculated as follows:
s* -
"•fs — • H '
271 H? +71 d2 C-. + 27T { — )
1 - Vc ' -
CALCULATIONS:
Calculating
r _ i
H/c ^"°
1 the C Factor, C2: "2 Vl.992 + 0.09 l(ff fa)/
1-1= 5 cm
a= 3 cm
C2 =0.842 Table 1. Field Data
Elapsed Time
Water Level
Reading Time Interval
(cm)
(sec) (sec)
0
I
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
0
120
240
360
480
600
720
840
960
1080
1200
1320
1440
1560
1680
1800
1920
2040
0
120
120
120
120
120
120
120
120
120
120
120
120
120
120
120
120
120
. Rate of Water
_ Water Level LevefChange
Change, R (cm) &
1 (cm/s)
0.0
4.6
5.8
6.5
7.2
7.8
8.3
8.8
9.2
9.6
9.9
10.2
10.6
10.9
11.3
11.6
11.8
12.2
0.0
4.6
1.2
0.7
0.7
0.6
0.5
0.5
0.4
0.4
0.3
0.3
0.4
0.3
0.4
0.3
0.2
0.4
O.OOE+00
3.83E-02
l.OOE-02
5.83E-03
5.83E-03
5.00E-03
4.17E-03
4.17E-03
3.33E-03
3.33E-03
2.50E-03
2.50E-03
3.33E-03
2.50E-03
3.33E-03
2.50E-03
1.67E-03
3.33E-03
Appendix E
-------
INNOVATIVE WASTE CONSULTING SERVICES, LLC
6628 NW 9th Blvd., Suite 3, Gainesville, FL 32605, USA
APPENDIX E-Field Saturated Hydraulic Conductivity of Cover Soil
at the Vieques Landfill
ENGINEER: Brett Tooley
DATE: 4/5/2011
PROJECT NAME: Puerto Rico Landfill Closure Evaluation
CHECKED BY: Jon Powell
DATE: 4/8/2011
Fhe rate of change between the 16th and 34th minute of testing continued oscillating around a central
/alue, which was selected to be a rate of change of 0.35 cm per interval.
R1= 0.35cm
T= 120 sec
= 2.92E-03 cm/sec X =
35.22 cm2
Qi = 0.103 cm3/sec
Calculating the hydraulic conductivity, K fs:
Kfs= 9.0E-05 cm/sec
0, =
K*. =
CONCLUSION:
The calculated field saturated hydraulic conductivity of the cover soil at the closed Vieques Landfill was 9.0 x
10~5 cm/sec.
REFERENCES:
SoilMoisture Equipment Corp (2005). Model 2800K1 Guelph Permeameter Operating Instructions. Santa Barbara, CA.
Appendix E
-------
Appendix F - Supplemental Site Figures: An Evaluation and Analysis of Past Landfill
Closures in Puerto Rico as Guidance for Current and Future Closures
Approximate Waste Limit
Figure F-l. Aerial Photograph of the Rincon Municipal Landfill with Supplemental Site Information.
1. Groundwater well locations are approximate based on information gathered from a site inspection
conducted by EQB in February 2002.
2. The downward surface grade arrows shown in the figure are conceptual and represent only relatively
steep slopes as identified in the field by the project team.
3. The waste limit shown is approximate based on information provided in the closure plan prepared
for the site by Garcia, Cabot y Asociados in 1994.
4. The location of the stream, "Quebrada Los Ramos/' is approximate and was adapted from a similar
depiction within Google Maps.
5. The location of the stockpiled plastics is approximate and is based on the visual observations of the
project team during the site visit.
6. The closed landfill has been used as a plant nursery for an unknown period of time. Historical documents
indicate that the municipality sought permission for an alternative use of the landfill sometime before
March 2002. Greenhouses and numerous potted plants were found at the site during the site visit.
Appendix F 1
-------
Figure F-2. Aerial Photograph of the Closed Rincon Landfill with Supplemental Site Information.
1. The waste limit shown is approximate based on information gathered in the field.
2. The "Area of Recent Waste Deposits" shown in the figure points to the general location where
apparently fresh garbage had been deposited. Numerous discrete piles were observed
throughout the site; however, the piles were predominantly concentrated at the south end of
the site near the entrance.
3. Inhabitants of the buildings identified in the figure confirmed that the structures constructed on
the landfill surface were, in fact, residential buildings.
Appendix F
-------
Approximate Waste Limit
Figure F-3. Aerial Photograph of the Cabo Rojo Municipal Landfill with Supplemental Site
Information.
1. The downward surface grade arrows shown in the figure are conceptual and represent only
relatively steep slopes as identified in the field by the project team.
2. The waste limit shown is approximate based on information provided in the closure plan
prepared for the site by Jordan, Jones, and Goulding in 1994, and information gathered in the
field.
Appendix F
-------
Figure F-4. Aerial Photograph of the Closed Vieques Landfill with Supplemental Site Information.
1. The downward surface grade arrows shown in the figure are conceptual and represent only
relatively steep slopes as identified in the field by the project team. The site was predominantly
flat with the only significant elevation change observed at the north end adjacent to the beach.
2. The waste limit shown is approximate based on information gathered in the field.
3. The "Area of Recent Waste Deposits" shown in the figure points to the general location where
apparently fresh garbage had been deposited. Discrete piles were observed throughout the
site.
Appendix F
------- |