mjAflJI^ai WASTE MANAGEMENT ^ ^ » « ^ ^ ^ ^ ^ ^ H Closed Site Management Group • V V V "® 1000 Parkwood Circle W A S T E MANAlGEMEMT Suite 700

Atlanta, GA 30339 Ph. 770-805-3520

March 19,2009

Mr. Scott Miller Remedial Project Manager U. S. Environmental Protection Agency Atlanta Federal Center, 10* Floor 61 Forsyth Street Atlanta, Georgia 30303

RE: HIPPS ROAD LANDFILL

Dear Mr. Miller:

Waste Control ofFlorida, Inc. (WCF) is please to provide the attached review letter prepared by our consultant, Colder Associates Inc. (Colder). As you will read in the review letter, Colder examined the March 21,2007 EPA memorandum prepared by William O'Steen and concludes that the off-site groundwater remediation should be considered complete. As such, WCF requests that EPA provides written approval that the ofiF-site groundwater remediation is considered complete and that ofiF-site monitoring wells be properly abandoned. In addition, groundwater iinpacts from the landfill have not been reported for more than 20 years. WM requests that EPA delist the Hipps Road Landfill from the Superfund program.

We trust that this information is sufficient for your needs. Should you have any questions regarding this request, please call me at (770) 805-3366.

Sincerely,

Waste Control ofFlorida, Inc.

Mr. /^xander Lacsamana, P.E.

Enclosure

cc: March Smith, WCFI Don Miller, Golder

10536531

Golder Associates Inc. _

9428 Baymeadows Road, Suite 400 • M J K S M W G o l C l C l * Jaclcsonville. FL USA 32256 % # ^ r A ^ T ^ ' l ^ T l * _ Telephone (904) 363-3430 ^ m ^ ^ x L S S O C l c l l C S Fax (904) 363-3445 www.golder.com

March 18,2009 073-82629

Waste Control ofFlorida, Inc. 1000 Parkwood Circle Suite 700 Atlanta, Georgia, 30339

Attn: Mr. Alexander Lacsamana. P.E.

RE: REVIEW OF GROUNDWATER REMEDIAL ACTION HEPPS ROAD LANDFILL, JACKSONVILLE, FLORIDA

Gentlemen:

On March 21, 2007, EPA produced a memorandum conceming the Hipps Road Landfill. The memorandum was prepared by William O'Steen ofthe Technical Services Section and sent to Mr. Scott Miller, EPA's Remedial Project Manager for the Hipps Road Landfill NPL site. Waste Conlrol of Florida, Inc. asked Golder Associates Inc. (Golder) to review and comment on the memorandum with the aim of evaluating the effectiveness of the groundwater remedial action at the site. Contained herein is Golder's review.

Backeround

The Hipps Road landfill was closed consistent with the Superfund process. The remedial investigation (RI) and feasibility study (FS) were completed in 1986 and the Record of Decision (ROD) was signed in 1986. The remedial design (RD) was initiated in 1989. The remedy for the site included installation of a proper landfill cover, and the construction and operation of an off-site groundwater recovery and on-site treatment system. The groundwater recovery system operated from 1994 until 1999. Since that time, monitored natural attenuation (MNA) has been the remedial action for off-site groundwater.

Comments on March 21. 2007 Memorandum

The EPA memorandum provided a fairly detailed evaluation of conditions of the site in 1986 (using the ROD as a reference), hi addition, information from the early years was also obtained from the 1995 ATSDR summary of site conditions. The reviewer was probably unaware, but the ATSDR 1995 reporl was not considered scientifically unbiased at the time it was written as researchers for the reporl were heavily influenced by members ofthe public who were plaintiffs in a law suit against Waste Control of Florida at the time. When lhe ATSDR report was released, Golder conducted a review that pointed out many inaccuracies in the report. It is also unfortunate thai thc reviewer did nol consider information from the RI report, and then later from the RD report, as a lot more informalion was available in those reports.

The following provides comments on the memorandum.

OFFICES ACROSS AFRICA. ASIA. AUSTRAUA, EUROPE. NORTH AMERICA AND SOUTH AMERICA

Waste Control of Florida, Inc. ' " March 18,2009 Attn: Alexander Lacsamana -2-_ 073-82629

Page 2, Table l - I believe that all detections reported in Table 1 (in the memorandum referred to as data from around the landfill) actually represent data collected from boreholes completed within the landfill (i.e., leachate). During the 1985 RI sampling event, groundwater samples from monitoring wells in well clusters immediately downgradient of the landfill (MW-D, MW-E, and

MW-F), contained estimated values of a Few constituents, but most reported detections were constituents that are considered laboratory or sampling artifacts. Carbon disulfide was reported in groundwater samples from clusters MW-E (at 55 feet below ground surface [bgs]) and Cluster F (al 10 feet bgs). Chloroform was reported in groundwater samples from cluster MW-D (at 55 feet bgs and 80 feet bgs). Only the shallow well at cluster MW-E (at 10 feet bgs) had groundwater samples that reported toluene and chlorobeneze (two of the constituents on Table 1). Both constituents were validated as estimated values, as detections were below.the established minimum quantitation limils. As part of the remedial design process groundwater samples were collected from these same wells in November 1998 and analyzed' with better minimum quantitation limits. No organic constituents were detected in groundwater samples from; any of these wells during the RD sampling. This is significanl as it relates to time of release. If the off-site impacts came from the landfill, the release had to have occurred prior lo the mid 1980s. In fact, it must have occurred so much ahead ofthe mid 1980s that the plume had completely passed the near-site monitoring points by that timeframe.

Page 3, 2"^ paragraph - The reviewer notes that different off-site wells are currently sampled than were sampled in the RI. The reason for this was that the RI relied on a number-of private wells and USGS wells for the delineation of off-site impacts. Concem was raised at the time because private wells were not constructed appropriately for groundwater sampling and the USGS wells were constructed of PVC pipe with joints glued together using PVC glue. Therefore, a complete set of new wells were installed during the pre-design investigation of the RD.

Page 5, Contaminant Fate & Transport - The first two paragraphs discuss the possible timing of a release frora the landfill. In paragraph 1, the reviewer notes that by 1983 much of the contamination from the landfill had dispersed. Later in the same paragraph, the reviewer notes that post-Rl monitoring data indicate that the landfill is no longer a source for groundwater impacts. However, in the next paragraph, a calculation is performed that suggests no movement from the landfill over the prior 12 years or more. Considering the memorandum was prepared in 2007, the timing should be something like 22 years from the RI dala of 1985 and 19 years from the RD data. This information is important as it is used in later contaminant distance projections.

It is interesting lo go back further and review a timeline of the landfill operation, closure, and contaminant manifestations. The site was.used as a landfill from 1967 to 1970 (three years). Off-site contamination was noted in 1972 (five years after start of landfill operations), ll is not indicated where the private well was in which contaminants were reported in 1972, however if it was even just a few hundred feel from the landfill, the landfill would not likely have been the source, as the contaminant would have had to migrate down into the lower portion ofthe aquifer and then migrate the distance to the well. More contaminants were delected in private wells in the lale 1970s early 1980s. Some of these detections were on the order of 2,000 feet from thc northeast comer of the landfill. If the landfill was the source for these impacts, again the rate of Iravel would have lo have been very rapid. By the lime of the RI and RD (1980s), impacted groundwaler was nol present in the vicinity ofthe landfill, based on wells installed adjacent to the landfill. The end of the release must have occurred significantly before the mid 1980s as there was not even a trace of residual contaminants in the wells adjacent to the landfill in 1988. Since then, contaminants have been delected in this same off-site area for 20 years or more. It seems

Golder Associates

Waste Control ofFlorida, Inc. March 18, 2009 Attn: Alexander Lacsamana ^3- 073-82629

unlikely that there would be such'a rapid movement away from the site (in the early years) and then contaminant migration stops and contaminants remain in the area of off-site contamination for so many years.

Page 8, 3"* paragraph - The reviewer performs a calculation that provides some justification that landfill derived contamination could still be upgradient of TM W-9I and the other two monitoring points discussed in the memo. What the analysis fails to consider is that at the time lhat the RD investigations were conducted, the contamination identified as off-site contamination was separate and distinct from the landfill. The clean contaminant boundary was only about 300 feet upgradient of TMW-9I. Consequently with the 19 to 24 years (instead of 12), the significantly shorter distance (300 feet), and five years of active remediation, the clean waterfront vvould have flushed through the area around TM W-9I, even considering back-diffiision out of lower hydraulic conductivity zones. ^

The reviewer then conducted an interesting analysis looking at a number of organic constituents and in particular the magnitude of concentrations and frequency of detections measured. Vinyl chloride concentrations decreased and the frequency of detection decreased over the period examined. The reviewer noted that this behavior was consistent with the conceptual model of groundwater behavior resulting from landfill source control and groundwater remediation. It is noted lhat the behavior is consistent with a historical release (long since controlled) from any source (not necessarily the landfill). The olher constituents did not follow the vinyl chloride behavior pattem. The trends for three of the constituents (benzene, chlorobenzene, and 1,4-dichlorobenzene) were not consistent with the vinyl chloride trend in either concentrations or frequency of detections (sometimes increasing and sometimes decreasing). The logical conclusion is that these releases did not come from the same source as the vinyl chloride, and in fact are not consistent wilh a source lhat has been cut off, as the assumed landfill source has been for the past 20 years or more.

The reviewer examined septic tanks as possible sources of contamination. The reviewer noted thai all of the detected constituents were present in household products, gasoline, and other lliels. While septic tanks were the focus in the memorandum, it would presume that all of these house­hold products were flushed down the drain, which may or may not be the case. The Hipps Road Landfill site is located in an area where there arc a substantial number of "do-it-yourselfers." During the RD investigations, it was noted that one property converted an old shed into an automobile painting shop. It would not be inconceivable lhat releases of these types of compounds occurred while oil changes were conducted and while fiieling lawn mowers and other household equipment. These incidental sources could produce the contamination rioted, without the classical septic tank signature that is discussed in the memorandum.

Recent Groundwaler Data

Data from the August 2008 semi-annual sampling event included results from six wells. Groundwater samples from four of the wells had dctcctible levels of organic constituents with only two samples having exceedances of the ROD cleanup criteria. Benzene, which as described above likely comes from a source olher than the landfill, was reported in samples from wells RW-2 (3.2 Hg/L) and TMW-9I (3.9 Hg/L), which are above the cleanup criteria of 1.0 ug/L. Other compounds, such as chlorobenzene and 1,4-dichlorobenzene, which were described above as likely coming from a different source, were also present in the samples but not above cleanup criteria. Vinyl chloride, which was described above as possibly coming from the landfill, was nol detected in any of the

Golder /^sociates

Waste Control of Florida, Inc. March 18,2009 Attn: Alexander Lacsamana ^4- 073-82629

samples. Data from the February 2009 sampling was also reviewed. Data from the six wells sampled in February 2009, indicated no constituents above cleanup criteria.

Conclusions

The EPA memorandum, with certain corrections, provides two lines of evidence that groundwater remediation at the Hipps Road landfill should be considered complete. The first line of evidence is the groundwater flow, or flushing analysis. In 1988, at the time of the RD investigations, the impacted groundwater was separate and distinct from the landfill. A "clean" groundwater boundary was identified as only marginally upgradient ofthe well TMW-9I. In the 19 years since, the flushing of uncontaminated groundwater should have occurred and the groundwater in 'l'MW-9I would not be impacted, imless groundwater in the vicinity of TMW-9I was receiving impacts from different and local sources. Monitoring between the edge of the landfill and TMW-9I has confirmed that there has been no subsequent release from the landfill. The second line of evidence suggests that compounds other than vinyl chloride likely originated from sources other than the landfill. These compounds are the only constituents remaining in groundwater at the site. Therefore, remediafion of groundwater impacts from the Hipps Road landfill should be considered complete.

We trust that this review meets with you approval. Should you have any questions or comments, please call.

Sincerely,

GOLDER ASSOCIATES INC.

Donald J. Miller Principal/Senior Consultant

DJM/me

cc: March Smith

Golder Associates