704560 Remedial Project Manager U.S. Environmental ...

Mr. Gary Miller (6SF-AP)Remedial Project ManagerU.S. Environmental Protection Agency Region 61445 Ross Avenue, Suite 1200Dallas, Texas 75202

Re:

Many Diversified Interests Superfund SiteRemedial Investigation Report for Operable Unit 1Screening-level Ecological Risk Assessment for Operable Unit 1Human Health Risk Assessment for Operable Unit 1

Draft Documents Review Comments

Dear Mr. Miller:

The Texas Commission on Environmental Quality (TCEQ) has completed its review of thereferenced draft documents prepared on behalf of the U .S. Environmental Protection Agency(EPA). Below find TCEQ’s review comments .

Draft Remedial Investigation Report for Operable Unit 1 (OU-1 RI)

November 5, 2003

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Response to 8579, 8580 and 8622file code IX.B.5.a.

CC/Task: 730009/704560

No. Section Comment1 Figure The legend needs correction to indicate that the blue line represents the

11, potentiometric contour elevation (MSL), not “judgmental sample location .”etc. Conflicting and crossing contour lines need to be resolved or explained . This

comment applies to the many other locations where this figure is used inother MDI documents .

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No. Section Comment2 5.0 The term “sediment” should be reserved for use in reference to

5.1 .2 contemporary sediments as contemplated by Section 4 .7. “Sediment” seemsetc. to be used interchangeably with the term “soil” in reference to soil types

which were laid down as sediments prehistorically . Suggest that the term“sediment” be deleted and the term “soil” be used in those cases throughoutthe report. The FSP and the scope summaries presented elsewhere in thisdocument refer to subsurface “soil” sampling.

3 5.1 .1, Reference is made to the statement “Under a residential land use scenario,Figure

15surface soils are those that extend to a depth of 1 .5 feet bgs.” The potentialARAR 30 TAC §350 .4(88) establishes that in this scenario the potentialexists for human exposure via contact, ingestion and inhalation to a depth upto 15 feet bgs .

Based on review of the available “subsurface” (greater than 1 .5 ft. bgs)sample data, TCEQ does not believe that there is widespread leadcontamination exceeding the 500ppm protective level at depths greater than1 .5 ft. bgs . However, is appears likely that some of the exceedance areasshown on Figure 15 may run slightly deeper than 1 .5 ft. bgs . TCEQ suggestthat it is likely that in the process of initial development as a residential area,excavation and relocation of soils deeper than 1 .5 ft. bgs may occur. Wetherefore suggest that an attempt should be made to establish the verticallimit of lead exceeding 500ppm at the identified “hot spots” and that suchmaterial be quantified for possible mitigation by either remediation orinstitutional control .

4 5.1 .1 The text makes reference to background occurrence of arsenic . Specific,detailed supporting discussion needs to be provided to describe how thearsenic background level was established and what that level is .

5 5.1 .1 Reference is made to the phrase “Figure X presents the areal extent of lead inFigures13, 14 &

soil ...” and the title “Distribution of Lead in Soils .” Both phrases areincorrect in that only the extent of lead above the residential screening level

15 is depicted and discussed . Depiction of the areal extent of lead would show,through isopleth or some other devise, the distribution of lead detected atany concentration .

TCEQ urges that these discussions of lead occurrence also providedistribution and quantitative data relating to lead exceeding the 500ppmremoval action level as that is likely to be the basis of the remedial action .

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No. Section Comment6 5.1 .1 There needs to be discussion about COPC occurrence in surface soil which

may exceed groundwater protective concentrations .7 5.1 .2,

Table 15TCEQ notes that a limited number of COPCs were evaluated against cross-media (soil to groundwater) migration potential . This section needs toexplicitly identify what COPCs were and were not evaluated for thispathway and why . This discussion should be particularly detailed inrelation to all COPCs identified in Section 5.3.1 . pertaining to constituent-specific groundwater contaminant detections . There should be someexplanation for the decision to use the lead screening level for industrialworker exposure to surface soil as a criteria for evaluating soil togroundwater migration potential .

TCEQ points out that absent an EPA screening level for potential soil togroundwater migration at concentrations of concern, the potential ARAR 30TAC §350, Tier 1 Protective Concentration Levels for the soil togroundwater to ingestion pathway provides those screening criteria .

8 5.2 Waste materials should be discussed in the context of human health screeningcriteria.

9 5.2.4 Reference is made to the statement “TCLP analysis indicated that thefoundry sands are nonhazardous and, if excavated, could be managed as solidwaste.” This statement and section is misleading in that it is not made clearthat the characterization only applies to foundry sands which are notidentified as being contaminated with COPCs . Clearly, foundry sandsexcavated from a high-concentration lead hot-spot, may well exhibit thecharacteristic of toxicity when subjected to TCLP testing .

10 5.34.1

Reference is made to the SWBZ constituting “a Class A aquifer as defined inTexas Administrative Code, Title 30, Part 350 .” Please note that TexasAdministrative Code, Title 30, Part 350 (30 TAC §350 .52) does not useletter classification of groundwater but uses numerals to designategroundwater resource classification . Based on a review of the data includedin the OU-1 RI it appears that the SWBZ constitutes a “Class 2groundwater resource” as defined in 30 TAC §350.52 (Note the proper termis Class 2, not Class II) .

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Draft Screening-level Ecological Risk Assessment for Operable Unit 1

This document was reviewed by Mr. Larry Champaign of TCEQ’s Remediation DivisionTechnical Support Section . Mr. Champaign’s comments follow :

I have completed my review of the SLERA for this site . It is my understanding that thefollowing site conditions/circumstances exist :

•

The site is located within two miles of downtown Houston and is surrounded by amixture of residential and industrial land use that is not very conducive to inhabitation byecological receptors .

•

Most of the site is covered by asphalt, concrete, roadways, or other man-made cover thatdoes not provide habitat for ecological receptors .

•

Buffalo Bayou is 3000 feet from the site, but studies indicate that neither sitegroundwater nor site storm water runoff reach the bayou .

•

There is an intermittent pool on-site that does not retain runoff for more than two daysafter a rainfall event .

•

There is also a non-ephemeral pool on-site that because of its shallow depth and substratetype does not support a benthic community or fish, but may contain a few amphibiansand is occasionally visited by waterfowl .

•

The site has been sold and there are plans for imminent residential redevelopment .

Based on these conditions, I concur with the findings of this report that there is little apparentecological risk at this site but that if this property is not redeveloped in the near future, that amore thorough ecological risk evaluation may be necessary . In the event of further investigation,the following general comments should be considered :

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No. Section Comment11 5.3.1 .X,

FiguresThroughout this section the text and figures state that they show thedistribution of contaminants in groundwater at the site . TCEQ suggests thatthese figures only show the distribution of ‘hits’ at sample points . It wouldbe most useful if the figures did in fact show an estimated extent ofcontamination exceeding screening levels in groundwater and the extent ofNAPL, similar to the approach used to depict lead distribution in soil onFigures 13 through 15 .

12 5.3.1 .4 In regard to arsenic, the possibility of an offsite source should be confirmedby placement of sampling points at the most upgradient edge of the sitewhere the suspected contaminant would enter the site boundary .

023012

1 .

With the exception of those Texas surface water quality standards (TSWQS) evaluated inthe kingfisher exercise described in Section 3 .4.2 of the TCEQ ERA guidance (TNRCC,2001), TSWQS are not protective of wildlife and should not be used to screen for theprotection of ingestion of water by wildlife . With regard to some of the site COPCs, theresults of the kingfisher exercise indicated that the TSWQS for cadmium, copper, lead,nickel, and (for the most part) selenium are protective of wildlife (i.e., whenconcentrations of these COPCs are below their respective water quality standards, theyneed not be retained in the SLERA because of bioaccumulation) .

2 .

Eliminating a COPC from the SLERA because of a lack of toxicological data isinappropriate. A thorough review of the open literature (including compilation references)should be conducted to obtain toxicity values for these COPCs, or for suitable surrogatecompounds. Relevant toxicological endpoint(s) associated with the surrogate selectionshould be reviewed to evaluate whether the candidate surrogate is appropriate given theselected receptors/ food web . At a minimum, these COPCs and their lack of toxicologicaldata should be discussed in the uncertainty analysis .

3 .

PAHs are well-known to exert additive effects an should therefore be evaluatedcollectively . Sediment benchmarks for Total PAHs (e.g., MacDonald et al., 2000) are themost relevant for evaluating risk in a SLERA because PAHs almost always occur in theenvironment as mixtures. Benchmark values for individual (and, for marine sediments,low and high molecular weight) PAHs, should be used as guidelines to aid in thedetermination of disproportionate concentrations within the mixture that may be maskedby the total. If a PAH compound is present above detection and has not been eliminatedin accordance with any prior agreements, it should not be screened out unless itsconcentration has been combined with those of the other detected PAHs and the sum isbelow the benchmark for Total PAHs . Also, for a non-detected PAH, it may beappropriate to include a proxy value (e.g., one-half of the detection limit) in the sum,depending on prior agreements and/or policies in place at the site .

4 .

It is recognized that significant toxicological data gaps exist for both reptiles andamphibians ; however, data resources to assist in evaluating potential risk are emerging .For example, a database called the Reptile and Amphibian Toxicological Literature(RATL) has been issued by the Canadian Wildlife Service of Environment Canada (Pauliet al., 2000) and should be reviewed for applicable reptile and amphibian toxicologicaldata. The RATL database can be found on the Internet at :

http://www.cws-scf.ec.gc.ca/pub/tr/tech357/index_e .htm. Ecotoxicological information on reptiles andamphibians is also presented in Sparling et al.(2000) .

It is acknowledged that there may not be oral dose toxicity data for amphibians andreptiles for all COPCs . However, there are immersion and dermal absorption dataavailable and these are appropriate pathways for evaluation in place of or in conjunction

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with oral dose data, particularly for amphibians . In the event that no amphibian toxicitydata for the specific COPCs can be found, if it can be shown that concentrations areprotective of aquatic and benthic invertebrates and fish, then amphibians (not countingthreatened/endangered species) can assumed to be protected . For reptiles with no toxicitydata, a small bird with similar habitat niche and feeding habitats can be used as a surrogatefor the reptile (again not counting threatened/endangered species), but it is generallyadvisable to refrain from across-class extrapolations . Either of these assumptions, if used,will need to be discussed in the uncertainty analysis .

In addition to an evaluation of toxicity data for the amphibian water exposure pathway,the risk assessment should qualitatively evaluate (minimally) potential risks to reptilesthat may be exposed to releases from the facility, particularly where toxicity endpointsrelated to an ingested dose are not available. Qualitative evaluations could include anevaluation of the literature to identify :•

general information concerning reptilian sensitivity to broad classes of chemicals•

evaluation of body tissue residue studies associated with effects•

comparison of residue studies at impacted and non-impacted sites•

general population studies at impacted and non-impacted sites•

blood dosing studies related to effects associated with site chemicals, and•

evaluation of the toxicity of these chemicals to birds with similar habitat andfeeding requirements .

References

MacDonald, D.D., C.G. Ingersoll, and T.A. Berger. 2000. Development and Evaluation ofConsensus-Based Sediment Quality Guidelines for Freshwater Ecosystems. Arch. Environ.Contam. Toxicol. 39:20-31 .

Pauli, B.D., Perrault, J.A., Money, S.L. (2000) RATL: A Database of Reptile and AmphibianToxicology Literature. Technical Report Series No. 357E. Canadian Wildlife Service,Headquarters, Hull, Quebec, Canada.

Sparling, D.W., G. Linder, and C.A. Bishop (Editors). 2000. Ecotoxicology of Amphibians andReptiles . SETAC Press . SETAC Technical Publication Series .

TNRCC. 2001 . Guidance for Conducting Ecological Risk Assessments at Remediation Sites inTexas. Final. RG-263 (revised). December 2001 .

Draft Human Health Risk Assessment for Operable Unit 1

Based on a limited review of this document the TCEQ offers the following comments :

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Thank you for providing the TCEQ an opportunity to review the subject draft documents andplease do not hesitate to contact me at 512-239-2139 if you have any questions regarding thesecomments.

Sincerely,

Alan Etheredge, Project ManagerSuperfund Cleanup Section

AFE/mmw

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No. Section Comment1 3.2.3.3 See comment No . 9 on the OU-1 RI relating to groundwater classification

systems used in Texas .2 8.4 The report states that “installation of a water well in the SWBZ within

the site boundary for domestic use is prohibited by the city due tosubsidence issues .” TCEQ believes that this assertion is false andrequests that the specific city ordinance, if any, which effects this controlbe identified.

We are aware that the Harris-Galveston Coastal Subsidence District isempowered by the state to regulate certain wells in the county of the site .However, that District is not empowered to regulate wells for singlefamily dwellings with casing less than 5-inches diameter and generallydoes not prohibit the extraction of groundwater but regulates rates ofwithdrawal and charges fees for withdrawal . In summary, the TCEQ doesnot believe that the rules of the Harris-Galveston Coastal SubsidenceDistrict serve as an institutional control to prevent potential exposure togroundwater under the site.

Further, the TCEQ is not aware of any City of Houston Ordinance whichprecludes the extraction of (and potential human exposure to)groundwater within the City’s jurisdiction . We are aware of regulationswhich preclude the cross-connection between external water sources andthe City’s municipal water supply system, but again do not believe thatthese regulations serve as an institutional control to prevent potentialexposure to groundwater under the site .

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