RESPONSE ACTION CONTRACT FOR

REMEDIAL, ENFORCEMENT OVERSIGHT, AND

NONTIME-CRITICAL REMOVAL ACTIVITIES

IN REGION 6

FEASIBILITY STUDY REPORT FOR OPERABLE UNIT 2

MANY DIVERSIFIED INTERESTS SUPERFUND SITE

HOUSTON, HARRIS COUNTY, TEXAS

EPA ID NO. TXD008083404

Prepared For:

U.S. Environmental Protection Agency

Region 6

1445 Ross Avenue

Dallas, Texas 75202-2733

Work Assignment No. : 107-RICO-06CN

EPA Region : 6

Date Prepared : July 29, 2005

Contract No. : 68-W6-0037

Prepared by : Tetra Tech EM Inc.

Tetra Tech Project Manager : Luis Vega

Telephone No. : (214) 740-2007

EPA Work Assignment Manager : Stacey Bennett

Telephone No. : (214) 665-6729 

EPA Alternate Work Assignment Manager : Rafael Casanova

Telephone No. : (214) 665-7437
ii

CONTENTS

Section Page

ABBREVIATIONS AND ACRONYMS .............................................................................................v

EXECUTIVE SUMMARY.................................................................................................................1

1.0 INTRODUCTION..................................................................................................................1

1.1 PURPOSE..................................................................................................................1

1.2 SITE BACKGROUND...............................................................................................2

1.2.1 Site Location and Description..........................................................................2

1.2.2 Site History....................................................................................................2

1.2.3 Previous Investigations ...................................................................................5

1.3 SITE CHARACTERISTICS........................................................................................6

1.3.1 Site Climate ...................................................................................................6

1.3.2 Regional Geology...........................................................................................6

1.3.3 Regional Hydrogeology ..................................................................................7

1.3.4 Site Hydrogeology..........................................................................................8

1.4 SUMMARY OF RECENT RI ACTIVITIES................................................................8

1.5 SUMMARY OF RECENT REMOVAL ACTION ACTIVITIES................................. 10

1.6 SUMMARY OF SITE RISKS................................................................................... 12

1.6.1 Arsenic ........................................................................................................ 12

1.6.1.1 Arsenic in One Residential Yard.................................................. 14

1.6.1.2 Arsenic at Bruce Elementary School............................................ 14

1.6.2 Lead............................................................................................................ 15

1.6.2.1 Neighborhood Risk..................................................................... 15

1.6.2.2 Residential Yards and High-access Areas..................................... 15

1.6.2.3 Residential Crawlspaces.............................................................. 16

1.6.2.4 Lead Attribution ......................................................................... 16

2.0 REMEDIAL ACTION OBJECTIVES AND ARARS............................................................. 17

2.1 REMEDIAL ACTION OBJECTIVES....................................................................... 17

2.2 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS............... 17

2.2.1 Overview of ARARs..................................................................................... 17

2.2.2 Chemical-specific ARARs............................................................................ 19

2.2.3 Location-specific ARARs............................................................................. 19

2.2.4 Action-specific ARARs................................................................................ 19

2.2.5 To Be Considered......................................................................................... 20

2.3 GENERAL RESPONSE ACTIONS.......................................................................... 20

3.0 IDENTIFICATION OF TECHNOLOGIES............................................................................ 21

4.0 COMPARATIVE ANALYSIS OF ALTERNATIVES............................................................ 21
4.1 EVALUATION CRITERIA...................................................................................... 21

4.1.1 Threshold Criteria ......................................................................................... 21

4.1.2 Primary Balancing Criteria ............................................................................ 22

4.1.3 Modifying Criteria ........................................................................................ 23

4.2 INDIVIDUAL ANALYSIS OF ALTERNATIVES..................................................... 23

4.2.1 Overall Protection of Human Health and the Environment............................... 23

4.2.2 Compliance with ARARs.............................................................................. 23

4.2.3 Long-term Effectiveness and Permanence...................................................... 23

4.2.4 Reduction in Toxicity, Mobility, and Volume Through Treatment ................... 23

4.2.5 Short-term Effectiveness............................................................................... 23

4.2.6 Implementability .......................................................................................... 24

4.2.7 Cost............................................................................................................. 24

5.0 COMPARISON OF REMEDIAL ALTERNATIVES.............................................................. 24

6.0 REFERENCES..................................................................................................................... 25
CONTENTS (Continued)

iv

FIGURES

Figure Page

1 SITE LOCATION..................................................................................................................3

2 OU 2 SAMPLE LOCATIONS................................................................................................4

3 DISTRIBUTION OF LEAD IN SOILS AND SUMMARY OF REMOVAL ACTIONS............ 11

4 SUMMARY OF EPA AND TNRCC ACTIVITIES................................................................ 13
v

ABBREVIATIONS AND ACRONYMS

95UCL 95-Percent upper confidence limit 

AOC Area of contamination

ARAR Applicable or Relevant and Appropriate Requirement

ATSDR Agency for Toxic Substance and Disease Registry

bgs Below ground surface

Bruce Blanche Kelso Bruce

Can-Am Can-Am Resource Group

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act 

CFR Code of Federal Regulations

COPC Contaminant of potential concern

CRA Conestoga-Rovers Associates Services

EPA U.S. Environmental Protection Agency

FS Feasibility study

GRA General response action

HASP Health and safety plan

HDHHS City of Houston’s Department of Health and Human Services

HHRA Human health risk assessment

IC Institutional control

IEUBK Integrated Exposure Uptake Biokinetic

LDR Land disposal restrictions

MDI Many Diversified Interests 

mg/kg Milligram per kilogram

MSSL Medium-specific Screening Level

NCP National Oil and Hazardous Substances Pollution Contingency Plan

OU Operable unit

ppm Part per million

RA Remedial action

RAO Remedial action objective

RI Remedial investigation

ROD Record of Decision

SARA Superfund Amendments and Reauthorization Act of 1986

SJF San Jacinto Foundry

STAR Screening Targeted Areas at Risk

START Superfund Technical Assistance and Response Team 

SWBZ Shallow water-bearing zone

TAC Texas Administrative Code

TBC To be considered

TCEQ Texas Commission on Environmental Quality

TCLP Toxicity characteristic leaching procedure

TESCO Texas Electric Steel Casting Company

Tetra Tech Tetra Tech EM Inc.

TNRCC Texas Natural Resource Conservation Commission

TXDOT Texas Department of Transportation

USDA U.S. Department of Agriculture

XRF X-ray fluorescence
ES-1

EXECUTIVE SUMMARY

This report presents the feasibility study (FS) for Operable Unit 2 (OU 2) at the Many Diversified 

Interests (MDI) Superfund site located in Houston, Texas. The purpose of the FS is to evaluate remedial 

alternatives for OU 2 through a systematic approach that includes: (1) developing remedial action 

objectives (RAO); (2) identifying general response actions (GRA); (3) screening the GRAs; (4) 

combining these technologies into remedies; and (5) evaluating these remedies. These remedies were 

evaluated based on the following seven of the U.S. Environmental Protection Agency (EPA)’s nine 

criteria: (1) overall protection of human health and the environment; (2) compliance with Applicable or 

Relevant and Appropriate Requirements; (3) long-term effectiveness; (4) reduction in toxicity, mobility, 

and volume through treatment; (5) short-term effectiveness; (6) implementability; and (7) cost.

During the remedial investigation (RI), lead was detected at concentrations greater than or equal to the 

EPA Region 6 Human Health Medium-specific Screening Level (residential) in surface soils within the 

OU 2 Study Area (Tetra Tech EM Inc. 2005a). During the RI, EPA conducted a removal action at those 

residences where lead concentrations in soil met or exceeded the EPA Region 6 cleanup level of 500 parts 

per million (ppm). Five residences were not addressed during the initial removal action. During May 

and June 2005, a second removal action was performed to address these five remaining properties.

The RAO for OU 2 is:

Reduce the risk posed to residential receptors by lead concentrations in the soil greater than or 

equal to the EPA Region 6 cleanup level established for the site (500 ppm).

Based on the previously conducted removal actions at Operable Unit 2, the RAO for the site has already 

been achieved. Therefore, only one alternative was evaluated:

Alternative 1 – No Action
1

1.0 INTRODUCTION

This report presents the feasibility study (FS) for Operable Unit (OU) 2 at the Many Diversified Interests 

(MDI) Superfund site located in Houston, Texas. This FS report was prepared in accordance with the 

National Oil and Hazardous Substances Pollution Contingency Plan (NCP) and the U.S. Environmental 

Protection Agency (EPA) “Guidance for Conducting Remedial Investigations and Feasibility Studies 

under the CERCLA [Comprehensive Environmental Response, Compensation, and Liability Act]” (EPA 

1988). Tetra Tech EM Inc. (Tetra Tech) prepared this FS report for EPA Region 6 as part of Work 

Assignment No. 107-RICO-06CN under Response Action Contract No. 68-W6-0037.

OU 2 consists of surface soils in off-site residential and high-access areas that may have been impacted 

by heavy metals as a result of activities at the MDI facility. During the 2003 remedial investigation (RI) 

for MDI, off-site soil samples were collected at residential yards, including apartment complexes, and 

from exposed soils in high-access areas (schools, parks, and daycare centers) within the Blowdown Area 

and the East Blower Area, which are collectively referred to as the “OU 2 Study Area” throughout this 

report. 

For the purposes of this report, “off-site” refers to the neighborhoods surrounding the MDI site, while 

“on-site” refers to the area within the fenced boundaries of the former Texas Electric Casting Company 

(TESCO) foundry site. Both on-site and off-site areas comprise the MDI Superfund Site (Site).

1.1 PURPOSE

The CERCLA RI/FS process is an iterative process that (1) characterizes threats to human health and the 

environment posed by hazardous substances released at a site, and (2) evaluates potential remedial 

alternatives to mitigate those threats. The RI report for OU 2 has been submitted under separate cover 

(Tetra Tech 2005a). The FS process of developing and evaluating remedial alternatives consists of the 

following steps: 

• Develop remedial action objectives (RAO) that specify contaminants and media of concern, 

volume of each affected medium, and remediation goals. 

• Develop general response actions (GRA) that can be taken for each medium to satisfy RAOs. 

Consider containment, treatment, removal, or other actions singly or in combination in 

developing GRAs.

• Identify and screen technologies for each GRA to eliminate technologies that technically 

cannot be implemented or are not cost-effective.

• Evaluate process options for each technology.
2

• Assemble retained technologies into alternatives and develop the alternatives.

• Conduct a detailed analysis of the alternatives based on the criteria identified in the NCP at 

Title 40, Code of Federal Regulations (CFR) Part 300.430(e)(9).

The purpose of this FS is to identify remedial alternatives that are appropriate for OU 2, and evaluate the 

alternatives based on the following criteria: (1) overall protection of human health and the environment; 

(2) compliance with Applicable or Relevant and Appropriate Requirements (ARAR); 

(3) long-term effectiveness; (4) reduction in toxicity, mobility, and volume through treatment; (5) shortterm effectiveness; (6) implementability, and (7) cost.

1.2 SITE BACKGROUND

The following sections provide site background information, including site location and description, 

ownership, history, and previous investigations.

1.2.1 Site Location and Description

The MDI site (OU 1), located at 3617 Baer Street in Houston, Harris County, Texas, is an abandoned 

foundry facility located approximately 2 miles east of downtown Houston and approximately 1 block 

south of U.S. Interstate Highway 10 (Figure 1). The MDI property occupies approximately 36 acres in an 

area of mixed industrial and residential land use. The MDI property is bounded by Hare Street to the 

north; National Vinegar Company and Press Street to the east; the former Texas & New Orleans Railroad 

right-of-way beyond the easement to the south; and Bringhurst Street to the west. 

OU 2, which is the focus of this FS, is the off-site area that was speculated to have been impacted by 

releases from activities at the MDI site. For the most part, the OU 2 Study Area consists of single-family 

homes, although several churches, a community center, and the Kelly Village housing complex are also 

located within the study area. Figure 2 shows the layout of the MDI Superfund Site (both OU 1 and OU 

2), as well as all investigative samples collected during the OU 2 RI.

1.2.2 Site History

In 1926, TESCO began operations as a metal casting foundry. The TESCO foundry initially occupied the 

former Houston Brick Works facility. The foundry expanded operations north of Baer Street and south of 

Gillespie during World War II. A second foundry facility was built on the eastern portion of the site 

during the latter half of 1970. TESCO primarily manufactured specialty molded parts such as large 

wheels, tracks, and mining equipment. The process area consisted of two casting plants: Plant I produced 

large castings, while Plant II produced smaller castings. Both plants maintained separate sand systems, 

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2
5

core ovens, mold makers, electric arc furnaces, pouring facilities, and cleaning, annealing, and heattreating process areas (Texas Natural Resource Conservation Commission [TNRCC] 1996). 

During the mid-1980s, the southern portion of the site was leased to Can-Am Resource Group (Can-Am; 

TNRCC 1996). Can-Am conducted a spent catalyst recycling operation using an experimental process. 

Very little is known about operations at the site during this time. Can-Am reportedly obtained between 

2,000 and 4,000 drums of spent catalyst from chemical plants and refineries along the Houston Ship 

Channel. By 1988, Can-Am ceased operations and the drums of spent catalyst were abandoned on site.

In 1990, MDI bought the TESCO note from Texas Commerce Bank. TESCO ceased operations in 

February 1991, and MDI foreclosed on the property. MDI reopened as the San Jacinto Foundry (SJF) on 

March 1, 1991. SJF continued operations until about June 1, 1992. MDI filed for Chapter 7 Bankruptcy 

in the U.S. Bankruptcy Court for the Southern District of Texas, Houston District on May 20, 1992. The 

on-site facilities were demolished as a salvage operation under order of the U.S. district bankruptcy court 

between March 1995 and January 1996 (TNRCC 1996). 

1.2.3 Previous Investigations

In 1996, EPA collected soils samples from approximately 100 residential properties north and west of the 

MDI site and identified 41 residences where lead concentrations in soils exceeded 500 milligrams per 

kilogram (mg/kg) (Agency for Toxic Substance and Disease Registry [ATSDR] 2000). In 1998, TNRCC 

(now known as the Texas Commission on Environmental Quality [TCEQ]) collected 143 residential soil 

samples (including Bruce Elementary School) and identified an additional 48 yards with similar lead 

concentrations in a study performed (ATSDR 2000). In 1999, the TNRCC conducted a removal and 

restoration of 89 residential yards to the north and west of the MDI site (Eagle Construction & 

Environmental Services, L.P. 1999). The removal action was conducted to remove surface soil with lead 

concentrations that exceeded 500 mg/kg to reduce the exposure of children and adults to lead. Following 

each removal, TNRCC conducted confirmation sampling to ensure that lead-contaminated soils did not 

extend below the 18-inch bgs excavation depth. Approximately 12,025 tons of soil were removed, 

characterized, and disposed of at a permitted landfill, with some of the soils being taken to a hazardous 

waste landfill, and some of the soils taken to a Subtitle D landfill.

Other work around the perimeter of the MDI site entailed the construction of temporary ground water 

monitoring wells to evaluate water quality near the MDI site (TERA, Inc. 1994; TNRCC 1998). The 

ground water investigations concluded that ground water contamination, if present, was localized, and did 

not occur on a broad scale. 
6

1.3 SITE CHARACTERISTICS

The following sections pertain to the characteristics of the MDI site only. A complete discussion of the 

geologic and hydrogeological setting is provided in the MDI RI for OU 2 (Tetra Tech 2005a).

1.3.1 Site Climate

The site’s proximity to Galveston Bay and the Gulf of Mexico affects the climate area, resulting in mild 

weather conditions and an average daily temperature of 70 °F. The minimum average daily low 

temperature is 43.6 °F occurring during January. The maximum average daily high temperature is 92.8 

°F occurring generally during August. The average total annual precipitation for Harris County is 46 

inches, with recorded annual extremes of 92.6 inches in 1900 and 17.7 inches in 1917 (U.S. Department 

of Agriculture [USDA] 1976). The mean annual lake evaporation for the area is approximately 18 inches 

(Bomar 1983).

Two principal wind regimes are present in the Texas Coastal Zone: southeasterly winds from March 

through November, and intermittent northerly winds from December through February. Prevailing winds 

in Harris County are from the south-southeast. The highest average wind speeds generally occur during 

April. The strongest seasonal winds in the area are produced by winter polar air masses arriving from 

the north, producing wind speeds of 20 to 40 miles per hour over a time period of 12 to 36 hours 

(Bomar 1983).

The most severe weather occurring in Harris County is produced by hurricanes and tornadoes. Only 20 

miles from the Gulf of Mexico, the Harris County area has an estimated one in eight chance of being 

affected by direct landfall of a hurricane in any given year; historically, the area is struck by a tornado 

approximately every other year (Bomar 1983).

1.3.2 Regional Geology

The MDI site is located within the Texas Coastal Plain region. This region is underlain by thousands of 

feet of sand and clay (coastal plain) deposits, which are mostly unconsolidated. Pliocene-Pleistocene 

sediments of the Texas Gulf Coast were deposited in fluvial, deltaic, and marine environments. The MDI 

site is directly underlain by the Beaumont Formation of the Pleistocene Epoch, which consists of former 

barrier island and beach deposits. The Beaumont Formation is made up of clay, silt, and sand formed 

from stream channel, point-bar, natural levee, back swamp, coastal marsh, and mud flat deposits. The 

Beaumont Formation contains calcium carbonate concretions, iron oxide, and iron-manganese nodules in 
7

zones of weathering. According to Fisher and others (1972), the Beaumont Formation under the site is 

made up of fluvial deltaic system deposits consisting of abandoned, mud-filled channels, and courses.

In the Houston area, the Beaumont Formation is underlain by the Pleistocene Lissie Formation. The 

Lissie Formation consists primarily of clay, silt, sand, and minor amounts of siliceous gravel, and is 

approximately 200 feet thick (Fisher 1982).

Underlying the Lissie Formation is the Willis Formation of the Pliocene-Pleistocene age. The Willis 

Formation is approximately 75 feet thick (Fisher 1982). The Willis Formation is underlain by the Goliad 

Formation (30 to 2,000 feet thick) and the Lagarto Formation (1,400 to 1,700 feet thick). Both of these 

formations are of Miocene age and were deposited in fluvial environments. The Goliad Formation 

consists primarily of sand, while the Lagarto Formation consists of mud and sand (Fisher 1982).

1.3.3 Regional Hydrogeology

The two uppermost regional aquifers present in the Houston-Galveston area are the Chicot and the 

Evangeline. Although there are other saturated zones nearer the ground surface, these units–which are 

used for drinking water supply–are encountered at depths of more than 500 feet below ground surface 

(bgs). The Chicot and underlying Evangeline are composed of alternating beds of clay, silt, sand, and 

gravel deposited in a series of fluvial-deltaic environments that were affected by rapid changes in 

sedimentation rate, regional subsidence of the Gulf of Mexico, and changes in sea level since at least the 

end of the Tertiary. 

The Chicot aquifer is composed of the Beaumont and Lissie Formations of Pleistocene age, as well as the 

overlying Holocene-age alluvium, where present. In some areas, the Chicot aquifer consists of one to 

four laterally discontinuous sand units (Beaumont Formation), which constitute the upper Chicot aquifer, 

underlain by the lower Chicot aquifer (Lissie Formation), which is one continuous sand body. Sand 

bodies in the upper Chicot aquifer vary in thickness and lateral continuity. Sands of the upper Chicot 

aquifer are typically less than 100 feet thick, although they coalesce locally, forming thicker bodies. 

The Evangeline aquifer, consisting of materials of the upper Miocene to Pliocene, is a thick, sanddominated interval occurring below the Chicot aquifer. The Evangeline aquifer is generally composed of 

the Willis and Goliad formations. The uppermost sands of the Evangeline aquifer are separated from the 

overlying Chicot aquifer by a continuous mud to sandy mud that is 30 to 200 feet thick. Several thinner, 

less continuous sands and muds separate the lower part of the Evangeline from the underlying Burkeville 

aquitard. In some areas, the Evangeline aquifer may contain brackish water (Hamlin and others 1988).
8

Reportedly, there are four active ground water wells located within a 1-mile radius of the site, none of 

which are used as a private or public drinking water supply (Tetra Tech 2005a). Three of the wells are 

within 1⁄2 mile of the Site and are operated by National Vinegar Company to generate process water; one 

well has been described as being screened in the undifferentiated Gulf Coast aquifer and the other two are 

screened in the Chicot aquifer. The fourth reportedly active well is within 1 mile of the site and operated 

by Houston Packing Company is screened in the Evangeline aquifer. Residences within close proximity 

to the site receive their potable water from the City of Houston water supply (Ecology & Environment, 

Inc. 1998). 

1.3.4 Site Hydrogeology

Because the focus of the RI for OU 2 was surface soils only, a ground water investigation was not 

performed as part of the OU 2 RI. Local information was collected as part of the OU 1 RI (Tetra Tech 

2003). In general, fine-grained sediments consisting of silty clays to clayey silts extend to 22 to 26 feet 

bgs. Beneath these fine-grained sediments, a more transmissive unit consisting of silty sands and poorly 

graded fine sands was encountered. These transmissive materials comprise the shallow water-bearing 

zone (SWBZ). Regionally, ground water in the SWBZ is reported to flow south toward Buffalo Bayou.

1.4 SUMMARY OF RECENT RI ACTIVITIES

An RI was performed at the MDI Superfund site during the spring and summer of 2003. The purpose of 

the OU 2 RI was to determine the nature and extent of heavy metals contamination in surface soils in 

those areas that were potentially impacted as a result of Site operations (OU 1). During the OU 2 RI, the 

following field activities were performed: 

• Collection of five-point composite shallow soil samples from 181 residences and highaccess areas within the predicted impact area, or OU 2 Study Area, with samples 

collected in both front and back yards at most houses; at each sample location, soil 

samples were collected from four depth intervals: 0 to 0.08 foot, 0 to 0.5 foot, 0.5 to 1.0 

foot, and 1.0 to 1.5 feet bgs.

• Collection of five-point composite soil samples from 40 locations that were not impacted 

by site activities; samples from each location were collected from the four depth intervals 

listed above; this data was used to establish site background concentrations of metals for 

comparative analysis.

• Collection of five-point composite soil samples from 10 locations at Blanche Kelso Bruce 

(Bruce) Elementary School; samples from each location were collected from the four 

depth intervals listed above.
9

• Collection of composite soil samples from 23 residential crawlspaces; crawlspace 

samples were collected from 0 to 0.08 foot bgs.

• Collection of five-point composite soil samples from seven locations at the National 

Vinegar Company facility immediately east of the MDI site; samples from each location 

were collected from the four depth intervals listed above.

The locations of these samples are presented on Figure 2. 

As discussed in the RI Report (Tetra Tech 2005a), air quality impact modeling was conducted to predict 

where (1) particulate matter from historical stack emissions would have been deposited onto the ground 

surface and (2) soil-lead concentrations may potentially meet or exceed the EPA Region 6 MSSLs for 

heavy metals associated with foundry activities. The planning-level modeling that was performed 

resulted in the delineation of contours (isopleths) with different estimates of deposition rates 

corresponding to different total lead concentrations:

• At the 1.8 gram per square meter per year (g/m2-year) isopleth, the lead concentration is expected 

to be about 1,600 mg/kg (immediate vicinity of the site [OU 1]).

• Between the 0.8 and 1.8 g/m2-year isopleths, the lead concentration is expected to be greater than 

400 mg/kg, but less than 1,600 mg/kg (concentration decreases with increasing distance from the 

site).

• Beyond the 0.8 g/m2-yr isopleth, the lead concentration is expected to be less than 400 mg/kg. 

During the 2003 RI, all residences within the predicted impact area of the OU 2 Study Area 

corresponding to lead concentrations ranging greater than 400 mg/kg (outer boundary of the OU 2 Study 

Area) to 1,600 mg/kg (immediate vicinity of the MDI site), as expressed by the 0.8 g/m2-yr isopleth (see 

Figure 4), were targeted for sampling.

With the exception of the samples collected at Bruce Elementary School, all samples were analyzed with 

a portable Niton® XL-702 x-ray fluorescence (XRF) device at the field command post. Samples 

collected from Bruce Elementary School were analyzed by a fixed laboratory prior to bringing the XRF 

analyzer on line; however, samples collected from the 0 to 0.08 foot bgs depth interval were subsequently 

analyzed for lead using XRF. At 10 percent of the sample locations, split samples were also submitted to 

a fixed laboratory for chemical analysis for verification of XRF results and to develop a site-specific 

correlation between lab and field lead concentrations. The XRF was used because it has been shown that 

for several metals–including lead, the primary contaminant of potential concern (COPC) at the MDI site–

an excellent correlation exists between the two analytical methods. A complete discussion of the 

comparative statistics has been included in the MDI OU 2 RI report (Tetra Tech 2005a).
10

Composite soil samples collected from the residences were compared to several screening criteria: 

(1) EPA Region 6 Medium-specific Screening Levels (MSSL); (2) median Site background concentration 

calculated from the 40 samples described in the previous bullets and identified on Figure 2; and (3) 

Texas-specific median background concentrations for metals in soils codified in the Texas Risk 

Reduction Program (TNRCC 1999). Figure 3 presents the distribution of lead in soils across the OU 2

Study Area, based on data collected during the 2003 RI.

1.5 SUMMARY OF RECENT REMOVAL ACTION ACTIVITIES

Following completion of the off-site field investigation in 2003, EPA tasked Weston Solutions, Inc. 

(Weston) with performing a time-critical removal action under the Superfund Technical Assistance and 

Response Team (START) contract. Surface soils with lead concentrations equal to or greater than 500 

parts per million (ppm; or mg/kg) were excavated and replaced with clean soils. The cleanup goal for 

lead in soils is protective of human health based on Integrated Exposure Uptake Biokinetic (IEUBK) 

modeling of actual data collected from other EPA Region 6 Superfund lead sites, namely RSR 

Corporation (EPA 1995), Tar Creek Superfund Site (EPA 1997), and Delatte Metals Superfund Site (EPA 

2000c). 

Although the cleanup goal for lead in soil was set at 500 ppm, the practical cleanup level was set at 463 

ppm. This lower value takes into account the average relative standard deviation for the XRF instrument 

of 37 ppm. The average relative standard deviation (a measure of the precision of the XRF instrument) 

was determined by averaging the reported instrument error values associated with field XRF lead analysis 

for all residential soil samples analyzed; therefore, any property with reported lead concentrations in soil 

greater than 463 ppm (or 500 ppm minus 37 ppm) was remediated as a conservative measure. Properties 

with lead contamination in soil extending to 1.5 feet bgs were over-excavated to 2 feet bgs. Confirmation 

samples were collected and submitted for fixed-laboratory analysis to ensure that lead-contaminated soils 

did not extend below the bottom of the excavation. 

During May and June 2005, a second removal action was performed under the START contract, with 

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ppm) that were not previously addressed during the 2003 EPA removal action. Three of the five 

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the 2003 EPA removal action; however, not all soils with lead concentrations greater than 463 ppm had 

been removed. 

Lead concentrations in soil samples collected from the Kelly Village housing complex (northwest corner 

of the OU 2 Study Area) were found to be greater at depth than at the surface. The Kelly Village housing 

complex did not have surface soil concentrations of lead above the EPA clean-up concentrations from 0-

0.5 foot bgs; therefore, there is no current risk to children or the community. The soil sample data did 

identify lead contamination at nine grid areas ranging from 0.5 to 1.5 feet bgs in the northeastern portion 

of the complex, but this also does not pose a current, immediate threat to the children or the community 

because of the clean soil and grass cover from 0 to 0.5 foot bgs. 

Figure 3 summarizes OU 2 removal action activities that were performed by EPA and TNRCC. Figure 4 

summarizes all of the EPA and TNRCC activities that have occurred within the OU 2 Study Area. More 

detailed information concerning the 2003 and 2005 EPA removal actions is available in the final reports 

submitted to EPA by its START contractor, Weston (2004; 2005). 

1.6 SUMMARY OF SITE RISKS 

For the MDI off-site areas, lead and arsenic (the latter in a single residential yard and at Bruce Elementary

School) were the only soil COPCs detected above the EPA Region 6 MSSLs after consideration of 2003 

and 2005 EPA removal activities. 

1.6.1 Arsenic

As discussed in the HHRA Report for OU 2 (Tetra Tech 2005b), arsenic was a COPC for OU 2 based on 

exceedances of the MSSL and background levels in three residential samples and five samples collected 

from Bruce Elementary School. Two of the three residential exceedances and one of the five Bruce 

Elementary School exceedances were addressed during removal actions when the locations were 

remediated for lead. Therefore, the remaining five samples (one residential and four from Bruce 

Elementary School) with arsenic concentrations exceeding the MSSL for residential soil and the 

maximum background concentration were evaluated in the HHRA. This evaluation involved performing 

a proportional comparison to the MSSLs for residential soil to estimate the cancer risk and noncancer 

hazards, as well as through the computation of an exposure point concentration (EPC). The uncertainties 

associated with these arsenic exceedances are discussed in the following sections.
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14

1.6.1.1 Arsenic in One Residential Yard

One residential yard had a reported arsenic concentration of 9.7 mg/kg (ppm; laboratory results reported 

in mg/kg) that exceeded its residential MSSL and the maximum median background concentrations (5.9 

mg/kg [ppm]). As discussed in the human health risk assessment (HHRA) for OU 2 (Tetra Tech 2005b), 

a resident exposed to an arsenic concentration of 9.7 mg/kg (ppm) would have an estimated cancer risk 

and non-cancer hazard index within the target thresholds. If a resident was assumed to be exposed daily 

for 30 years to the 9.7 mg/kg concentration, this would correspond to a cancer risk of 25 in 1 million (or

2.5 x 10-5), which is within the risk management range but below the “bright line” of 1 in 10,000 (or 1 x 

10-4) that would trigger CERCLA remediation. If a resident was exposed daily for 30 years, this would 

correspond to a noncancer hazard of 0.4, which is below the target threshold of 1.0. Therefore, risks 

associated with these arsenic exceedances of the MSSL are within the target risk range and do not require 

further evaluation. 

1.6.1.2 Arsenic at Bruce Elementary School

As described in the HHRA (Tetra Tech 2005b), a 95-percent upper confidence limit (95UCL) of 5.1 

mg/kg was calculated for the arsenic results reported for the Bruce Elementary School samples. In 

general, arsenic was not detected in the top inch of soil across the Bruce Elementary School property. 

The calculation of the 95UCL allowed an evaluation of arsenic across the sampled areas, not just the 

maximum concentration detected in the one limited strip of land adjacent to Bringhurst Street. A resident 

exposed daily for 30 years to the 95UCL concentration of 5.1 mg/kg at Bruce Elementary School, would 

(1) result in a cancer risk of 13 in 1 million (or 1.3 x 10-5), which is within the risk management range 

(10-6 to 10-4); and (2) correspond to a noncancer hazard of 0.2, which is below the target threshold of 1.0. 

Exposure at the elementary school yard is not the same as exposure over 30 years, so in this case, 

comparison of the arsenic maxima to residential soils is conservative; a site-specific child assessment 

would yield even lower cancer risks and noncancer hazards, given that exposure would be expected to 

occur only over the elementary school-age years (ages 4 to 12 at Bruce Elementary School), which would 

amount to approximately 8 years of exposure (for partial days only and limited soil access time during 

recess) rather than 30 years of exposure. Therefore, risks associated with these arsenic exceedances of the 

MSSL at Bruce Elementary School are within the target risk range and may not require further evaluation.
15

1.6.2 Lead

For the evaluation of lead in residential yards, lead results that exceeded 400 ppm and were below the 

practical removal action level of 463 ppm, or 500 minus 37 ppm (relative standard deviation of the XRF 

instrument), and thus not addressed during the removal actions, were evaluated using the IEUBK Model. 

1.6.2.1 Neighborhood Risk

The HHRA evaluated exposure to lead in soil on a “neighborhood” scale (Tetra Tech 2005b). That is, all 

soil lead results for the 0 to 0.08 foot bgs interval collected from residential property yards located in the 

OU 2 Study Area that were less than the practical removal action level of 463 mg/kg were evaluated using 

the IEUBK Model. No lead results from commercial properties or non-residential properties were included 

in the evaluation of “neighborhood risk.” The soil lead results for the residential properties were used as the 

soil/dust model input, and the “neighborhood risk” was determined by averaging the individual percentages 

(output of the model). The “neighborhood risk” for OU 2 was estimated at 1.433 percent of the exposed 

children in the neighborhood with a blood-lead level greater than 10 micrograms per deciliter; this 

percentage is below the EPA OSWER goal of 5 percent.

1.6.2.2 Residential Yards and High-access Areas

The lead concentrations across the four depth intervals yielded estimated percentages of children with 

elevated blood-lead ranging from 4.994 percent to 7.494 percent. Although the estimated percentages at 

individual residential locations with lead concentrations greater than 400 mg/kg exceed the EPA 

OSWER’s recommended threshold of 5 percent, the “neighborhood risk” of 1.433 percent is below the 

EPA OSWER goal. 

At Location 329 (Kelly Village housing complex), exposure to lead in soil in the common areas sampled

during the RI was evaluated. The common areas were evaluated as a combined exposure area, on a 

block-by-block basis, and as half-block areas. The 95UCL for each of these exposure areas was modeled 

using the IEUBK model. The percentage of exposed children predicted to have a blood-lead level greater 

than 10 μg/dL was 0.409 percent for the combined common areas, which is below the EPA OSWER goal 

of 5 percent. The risks for children exposed to soil in Blocks No. 1 and No. 3 (and the corresponding 

half-blocks) were below the EPA OSWER goal of 5 percent; risks for Block No. 2 (and its corresponding 

half-block) were greater than the EPA OSWER goal of 5 percent.
16

1.6.2.3 Residential Crawlspaces

For the crawlspace areas, 18 samples (including two field duplicates) had lead results that exceeded 400 

mg/kg and were evaluated using the IEUBK Model. Two exposure scenarios were evaluated (1:6 and 

3:4), which assumed 1 or 3 day per week exposure to soil in crawlspace areas. Although the percentage 

for several crawlspace samples for the 1:6 and 3:4 scenarios exceed the EPA OSWER-recommended 

threshold of 5 percent, the “neighborhood” risk of 1.433 percent is below the EPA OSWER goal.

Evaluation of the IEUBK results for the crawlspace samples should consider several important sources of 

uncertainty including (1) statistical data that indicates that the sources of lead in crawlspaces may not be 

attributable to the site; (2) limitation on access to crawlspace areas, and (3) assumptions that 

infants/toddlers would spend appreciable amounts of time each day in the crawlspace areas. Each of 

these uncertainties may result in an overestimation of site-related risk for the crawlspace areas. 

1.6.2.4 Lead Attribution

Several factors should be considered in interpreting these results. 

On July 29 and August 21, 2003, the City of Houston’s Department of Health and Human Services 

(HDHHS, Childhood Lead Poisoning Prevention Program) performed blood-lead screening of Fifth Ward 

resident children during the “Screening Targeted Areas at Risk (STAR) Project.” The EPA participated 

in the August 21st effort that targeted the OU 2 Study Area. The HDHHS’s analysis of the STAR Project 

blood data indicated that, out of the 49 children tested, none of these children exhibited blood-lead levels 

greater than the level of concern established by the Federal Centers for Disease Control and Prevention. 

A statistical evaluation comparing the off-site soil data with both the on-site soil and on-site waste (bag 

house) sample data has revealed that the MDI site is not the sole source of elevated lead concentrations in 

OU 2 soils. Other probable sources include historical deposition from vehicular lead-based fuel 

emissions and residential lead-based paint and plumbing solder. 
17

2.0 REMEDIAL ACTION OBJECTIVES AND ARARS

The cleanup goal for lead in soils at the site has been established at 500 ppm, which is protective of 

human health based on IEUBK modeling of actual data collected from other EPA Region 6 Superfund 

lead sites, namely RSR Corporation (EPA 1995), Tar Creek Superfund Site (EPA 1997), and Delatte 

Metals Superfund Site (EPA 2000c). Unacceptable risks at the site are associated with the properties with 

lead in soils above the EPA Region 6 cleanup level of 500 ppm. Once these properties have been 

addressed by removing those soils with lead concentrations greater than or equal to the cleanup level, no 

further action will be required for OU 2. The following subsections discuss the RAOs, ARARs, and 

GRAs for MDI OU 2. 

2.1 REMEDIAL ACTION OBJECTIVES

RAOs identify site-specific COPCs, media of concern, potential exposure pathways, and remediation 

goals, which are derived from the risk assessment findings and the evaluation of potential ARARs. 

Ground water at the MDI Superfund Site was addressed in the FS for OU 1 (Tetra Tech 2004), and is not 

a media of concern in OU 2. Because OU 2 has been well characterized and the focus of a removal 

action, there is only one RAO:

Reduce the risk posed to residential receptors by lead concentrations in the soil greater 

than or equal to the EPA Region 6 cleanup goal for the site (500 ppm).

2.2 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS

CERCLA, as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA), and its 

implementing regulation, the NCP at 40 CFR Part 300, require that CERCLA remedial actions (RA) 

achieve ARARs established under federal and state environmental laws and regulations that address 

wastes, pollutants, contaminants, RAs, location, or other circumstances at a CERCLA site. CERCLA 

also provides six ARAR waivers that may be invoked under specific circumstances. In addition to 

ARARs, EPA and the states may, as appropriate, identify other advisories, criteria, or guidance to be 

considered (TBC) for a particular release. 

2.2.1 Overview of ARARs

According to Section 300.5 of the NCP, “applicable requirements” means those cleanup standards, 

standards of control, and other substantive requirements, criteria, or limitations promulgated under federal 

environmental or state environmental or facility siting laws that specifically address a hazardous 
18

substance, pollutant, contaminant, RAs, location, or other circumstance found at a CERCLA site. 

According to EPA’s ARAR guidance “CERCLA Compliance with Other Laws Manual,” in order for a 

requirement to be applicable, (1) it must be substantive as opposed to administrative, (2) it must be 

promulgated through a federal rulemaking procedure or for state standards it must be of general 

applicability and legally enforceable, and (3) its jurisdictional prerequisites must be satisfied by the 

circumstances at the CERCLA site.

Section 300.5 of the NCP defines “relevant and appropriate requirements” as those cleanup standards, 

standards of control, and other substantive requirements, criteria, or limitations promulgated under federal 

environmental or state environmental or facility siting laws that, while not “applicable” to a hazardous 

substance, pollutant, contaminant, RA, location, or other circumstance found at a CERCLA site, address 

problems sufficiently similar to those encountered at the CERCLA site that their use is well suited to the 

particular site. 

The preliminary identification of ARARs involves considering a number of site-specific factors, including 

potential RA chemicals of concern at the site, physical characteristics of the site, and site location. A 

requirement is applicable if it specifically addresses or regulates the hazardous substance, pollutant, 

contaminant, action being taken, or other circumstances at the site. To assess whether a particular 

requirement would be legally applicable, it is necessary to evaluate specific jurisdictional prerequisites of 

the statute or regulation. All pertinent jurisdictional prerequisites must be met for the requirement to be 

applicable. Jurisdictional prerequisites include: 

• Who, as specified by the regulation, is subject to its authority.

• The types of substances and activities listed as falling under the authority of the regulation

• The time period for which the regulation is in effect

• The types of activities the regulation requires, limits, or prohibits

• If jurisdictional requirements are met, the requirement is applicable; if not, the next step is to 

consider whether the requirement is relevant and appropriate (EPA 1988).

ARARs identified for RAs are based on the chemicals present, the location of the site, and possible RAs 

for the site. The following sections present the chemical-, location-, and action-specific state and federal 

ARARs that may be pertinent to the MDI site. These ARARs are discussed again in Section 3 as they 

relate to specific potential RAs.
19

2.2.2 Chemical-specific ARARs

Few federal standards have been promulgated for contaminants in soil. Most screening and cleanup 

standards for soil are developed using EPA’s risk assessment and preliminary remediation goals 

processes. During the OU 2 RI, the extent of soils with lead concentrations equal to or greater than the 

EPA Region 6 residential MSSL were delineated (Tetra Tech 2005a). The MSSL for lead in residential 

soil was a TBC criterion. The action level established for the site was 500 ppm.

2.2.3 Location-specific ARARs

Location-specific ARARs restricts the concentration of hazardous substances or the conduct of activities 

due to characteristics of the site or its immediate environment. For example, location of the site or 

proposed RA in a flood plain, wetlands, historic place, or sensitive ecosystem may trigger locationspecific ARARs. Any RA that would affect these special locations must comply with the associated 

regulations. 

• Construction Permits. Proper permits for construction in rights-of-way would be required, 

and the city, county, or Texas Department of Transportation (TXDOT) may require roadway 

crossing agreements, if any additional excavation were required.

• Floodplain or Wetland Environments. 40 CFR Part 6 Appendix sets forth EPA policy for 

carrying out the provisions of Executive Orders 11988 (Floodplain Management) and 11990 

(Protection of Wetlands) and are potential location-specific ARARs. The site is not located 

within a floodplain and there are no wetlands near the site that would be impacted by cleanup 

actions at the site. 

• The Endangered Species Act, the National Historic Preservation Act, and the Archaeological 

and Historic Preservation Act also are potential ARARs that were considered. The MDI site 

is not located in an area affected by these acts. 

2.2.4 Action-specific ARARs

Action-specific ARARs are technology- or activity-based requirements or limitations for RAs. These 

requirements are triggered by the particular remedial activities conducted at the site and suggest how a 

selected remedial alternative should be achieved. These action-specific requirements do not in 

themselves determine the remedial alternative; rather, they indicate how a selected alternative must be 

conducted. 

There are no federal ARARs for institutional controls (IC). The NCP allows the use of ICs to supplement 

engineering controls as appropriate for short- and long-term site management to prevent or limit exposure 

to site-related contamination (NCP Section 300.430 [a][1][iii][D]). ICs may be required in order to 
20

prevent exposure to contaminated soils depending upon the remedy selected. State regulations that are 

potential action-specific ARARs regarding ICs are codified in Title 30, Texas Administrative Code 

(TAC) Part 350.111 (f). These regulations provide authority for the TCEQ to have a “deed notice” placed 

as an IC. Although the deed notice requires that information regarding potential site risks be recorded 

with the deed, they are not an enforceable prohibition against any activities occurring on a given parcel. 

Since the previously conducted EPA and TNRCC removal actions addressed all soils exceeding the cleanup criteria within the yards, ICs in the form of deed notices are not required. The EPA will be evaluating 

crawlspaces under a separate investigation and report for OU 3.

2.2.5 To Be Considered

In addition to ARARs, the preamble to the NCP provides agency advisories, criteria, or other “TBC 

guidance in helping to determine what is protective at a site or how to carry out certain actions or 

requirements” (55 Federal Register 8666, 8745, dated March 9, 1990). The preamble to the NCP states, 

however, that provisions in the TBC category “should not be required as cleanup standards because they 

are, by definition, generally neither promulgated nor enforceable, so they do not have the same status 

under CERCLA as do ARARs.” 

The Texas Risk Reduction Program Rule (30 TAC 350) is a TBC. The HHRA was used to evaluate the 

risks posed by site COPCs and may also be used to establish appropriate cleanup levels for contaminants 

in soil (Tetra Tech 2005b). 

2.3 GENERAL RESPONSE ACTIONS

GRAs are medium-specific actions capable of achieving the RAOs. EPA presumptive remedy guidance 

establishes treatment and/or containment of contaminated media as the GRA for metals-in-soils sites 

(EPA 1999). Treatment can be combined with other appropriate general actions to accomplish the RAOs. 

Consequently, GRAs may include treatment, containment, reduction/separation, disposal, extraction, 

monitoring, and ICs, or a combination of these and other general actions.
21

3.0 IDENTIFICATION OF TECHNOLOGIES

Since the soil exceeding the cleanup criteria for OU 2 has already been removed, no additional 

remediation is needed; therefore, no technologies have been identified or screened. 

4.0 COMPARATIVE ANALYSIS OF ALTERNATIVES

Since the soil exceeding the cleanup criteria has already been removed from OU 2, only the No Action 

Alternative was evaluated in the following sections. 

4.1 EVALUATION CRITERIA

This section presents the criteria used to evaluate the potentially applicable remedial technologies and 

summarizes those technologies that satisfied the criteria. EPA has established nine evaluation criteria to 

address these statutory requirements for CERCLA. The criteria can be classified into the categories of 

threshold criteria, primary balancing criteria, and modifying criteria. The evaluation is based on seven of 

the nine criteria. Modifying criteria (state or support agency acceptance and community acceptance) will 

be evaluated after the public comment period on the FS and proposed plan and prior to the finalization of 

the Record of Decision (ROD). The evaluation criteria categories and nine evaluation criteria are 

presented below. (Note: only eight criteria are listed because state or support agency acceptance and 

community acceptance are discussed together.)

4.1.1 Threshold Criteria

The following threshold criteria are requirements that each alternative must achieve to be eligible for 

selection as a permanent remedy:

Overall Protection of Human Health and the Environment – The overall protection of human health 

and the environment is evaluated for each alternative on the basis of the alternative’s ability to reduce the 

risk of exposure to contaminants. Each alternative also is examined to determine whether it creates 

unacceptable short-term risks to human health.

Compliance with ARARs – This criterion evaluates each alternative’s compliance with location-specific, 

chemical-specific, and action-specific ARARs. It also evaluates the potential for a waiver. These 

ARARs were identified and screened for relevance to the site in Section 2.1. 
22

4.1.2 Primary Balancing Criteria

The following primary balancing criteria are factors that identify key tradeoffs among alternatives:

• Long-term Effectiveness and Permanence – Long-term effectiveness and permanence are 

evaluated for each alternative on the basis of the magnitude of residual risk and the adequacy 

and reliability of controls used to manage remaining waste after response objectives have 

been achieved. Alternatives that offer long-term effectiveness and permanence halt, or 

otherwise mitigate, any potential for off-site contaminant transport and minimize the need for 

future engineering controls.

• Short-term Effectiveness – The evaluation of alternatives for short-term effectiveness takes 

into account protection of remedial workers, members of the community, and the 

environment during implementation of the RA and the time required to achieve cleanup 

goals. In this FS, schedule estimate durations are based on projected availability of materials 

and labor and may have to be updated at the time of remediation. Estimated durations are 

also based on good weather, the ability to create and receive adequate and authorized access, 

and the availability of required utilities. All time estimates assume that the selected remedial 

design, including construction drawings, has been approved and that all negotiations with 

contractors have been concluded.

• Reduction of Mobility, Toxicity, or Volume through Treatment – The statutory 

preference is to select an RA that employs treatment to reduce the mobility, toxicity, or 

volume of hazardous substances. The degree to which alternatives employ recycling or 

treatment is assessed, including how treatment is used to address the principal threats posed 

by the site.

• Implementability – Each alternative is evaluated with respect to the technical and 

administrative feasibility of implementing the alternatives as well as the availability of 

necessary equipment and services. This criterion includes such items as the ability to obtain 

services, capacities, equipment, and specialists necessary to construct components of the 

alternative; the ability to operate and monitor the permanence and effectiveness of the 

technologies; and the ability to obtain necessary approvals from other agencies.

• Cost – Accuracy of present worth costs is +50/-30 percent, in accordance with EPA guidance 

(EPA 1988; 2000b). Cost estimates are derived from current information, including vendor 

quotes, conventional cost-estimating guides (R.S. Means Company, Inc. 2002a; 2002b), and 

costs associated with similar projects. The actual cost of the project will depend on labor and 

material costs, site conditions, competitive market conditions, the final project scope, and the 

implementation schedule at the time the remedial activities are initiated. In estimating the 

present worth cost, discount rate and inflation are based on published values (EPA 2000a). 

Present worth costs for these items are based on 30 years of operation.
23

4.1.3 Modifying Criteria

The following modifying criteria must be considered during remedy selection:

• State or Support Agency Acceptance and Community Acceptance –The preferred 

alternative should be acceptable to state and support agencies. Also, the concerns of the 

community should be considered when selecting a remedy. The evaluation of these two 

criteria will be based on comments on the FS report and the proposed plan received during 

the public comment period and will be addressed in the Responsiveness Summary of the 

ROD.

4.2 INDIVIDUAL ANALYSIS OF ALTERNATIVES

The No Action Alternative was evaluated as detailed in the following sections. Under the No Action 

Alternative, no RAs will be conducted.

4.2.1 Overall Protection of Human Health and the Environment

The No Action Alternative will be protective of human health under current conditions. The IEUBK 

modeling predicts that blood-lead levels in residents at those locations where lead in soil is greater than 

500 ppm would exceed acceptable thresholds (Tetra Tech 2005b). The surface soils exceeding the 500 

ppm criteria have been removed; therefore, the No Action Alternative is protective.

4.2.2 Compliance with ARARs

This alternative will comply with the ARARs for the MDI site described in Section 2.2.

4.2.3 Long-term Effectiveness and Permanence

Long-term effectiveness has been achieved with the removal of contaminated soils.

4.2.4 Reduction in Toxicity, Mobility, and Volume Through Treatment

No reduction in toxicity, mobility, or volume will occur under the No Action Alternative.

4.2.5 Short-term Effectiveness

Implementation of the No Action Alternative at the MDI site does not present short-term risks to nearby 

residents because soils exceeding the cleanup criteria have already been removed from OU 2. The No 

Action Alternative can be implemented immediately. Because no RAs are included, no schedule of 

completion is included.
24

4.2.6 Implementability

The No Action Alternative can be readily implemented and will not hinder the implementation of RAs in 

the future. No equipment or services are required for the No Action Alternative.

4.2.7 Cost

The total cost for the No Action Alternative is $50,000. The total cost includes no capital costs. 

Operating costs are based on a review of site conditions every 5 years over a 30-year period. No other 

operation and maintenance costs will be included.

Five-Year Reviews are generally required on a site-wide basis by statute or program policy when siterelated hazardous substances remain at a site above levels which permit unrestricted use and unlimited 

exposure. Statutory Five-Year Reviews will be required for OU 1, since contaminants were found in the 

ground water, which prevents unrestricted use and unlimited exposure. These site-wide reviews will also 

include OU 2.

5.0 COMPARISON OF REMEDIAL ALTERNATIVES

Based on the previously conducted removal actions at OU 2, the RAO for the site has already been 

achieved. The EPA will be evaluating residential crawlspaces under a separate investigation and report 

for OU 3. 

Therefore, only one alternative was evaluated: 

Alternative 1 – No Action

Because only the No Action Alternative was evaluated, no comparison of remedial alternatives was 

conducted.
25

6.0 REFERENCES

Agency for Toxic Substance and Disease Registry. 2000. “Public Health Assessment for Many 

Diversified Interests, Incorporated, Houston Harris County, Texas, CERCLIS no. 

TXD008083404.” March 31.

Bomar, George W. 1983. “Texas Weather.” University of Texas Press. Austin, TX. 

Conestoga-Rovers Associates Services. 1999. “Drum Removal Action Final Report Many Diversified 

Interests Site, Houston Texas.” Prepared for the U.S. Environmental Protection Agency, Region 

6, Dallas, Texas. Reference ID 25986-16. December. 

Ecology & Environment, Inc. 1998. HRS Documentation Record, Many Diversified Interests, Inc., 

Houston, Texas, CERCLIS ID Number: TXD008083404. Prepared for the U.S. Environmental 

Protection Agency, Region 6, Dallas, Texas. September.

Fisher, W.L., J.H. McGowen, L.F. Brown Jr., and C.G. Groat. 1972. “Environmental Geologic Atlas of 

the Texas Coastal Zone, Houston-Galveston Area.” Bureau of Economic Geology, University of 

Texas at Austin. Austin, TX.

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