OAR Box 1131 

Prepped by Ollie Stewart 

Document Number: 

146) H-l-26 

Docket Number: 

A-83-22 

Printed 4/21/2008 2:34:13 PM Sheet 146 of 162 

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E 8 E 1 W 

Will 3 199? 

XK ALLIANCE 

MIWAWA Technologies Corporation 

February 12, 1988 

EPA AIR DOCKET 

-TZ-I'Ja^ 

DATE: 

TO: 

FROM: 

SUBJECT: 

Dave McLamb 

William Battye kM 

Reconciliation of Population Estimates Around Major Point Sources of 

Lead Emissions 

In response to Items (1) and (2) under Work Assignment 23 (EPA Contract No. 

69-02-4317, I have reviewed and compared the TRC estimate and our two estimates 

of populations around lead emission sources. I have also revised our 1987 

estimates to incorporate changes suggested by Donna Sledge, and to reflect the 

list of secondary lead smelters received from the Lead Industries Association 

in October 1987. 

Revisions to the 1987 Analysis 

In the 1987 analysis, we had assumed a typical distance of 600 meters between 

plant center and plant boundary for secondary smelters, and 400 meters for 

battery plants. This assumption was based on a review of a topographic maps 

for a small number of plants. Donna asked that we use smaller distances to 

represent the typical case, based on the example of primary smelters, where 

plant boundaries are sometimes within 200 meters of the plant center. In 

Table 1, I have revised the population estimates for these two categories using 

plant boundary distances of 200 meters for secondary smelters and 150 meters 

for battery plants. The Table 1 estimates also use the 1987 LIA secondary 

smelter list, reproduced in Table 2. 

Differences in Population Estimates 

As you know, the 1987 analysis used HEM-SHEAR to estimate the affected 

population around lead point sources. In 1985, we had estimated affected 

populations using the HEM-SHED model and 1983 lists of emission sources. 

TRC's estimates of affected populations (1986) were based on a survey of the 

emission sources. Our 1985 estimates covered total populations and 

populations of children within 1 kilometer of lead-acid battery plants, 2 

kilometers of secondary lead smelters, and 5 kilometers of primary lead 

smelters. TRC's 1986 estimate and our 1987 estimate both covered severa-1 

different exposure areas, including the 1 km, 2 km, and 5 km zones. This memo 

does not address the sizes of areas affected by emissions from lead sources, 

but only addresses the differences in population estimates for the 1 km, 2 km, 

and 5 km zones. 

500 Eastowne Drive, Chapel Hill. North Carolina 27514 919-489-6550 
P.3 

/X ALLIANCE 

Technologies Corporation -2-

TABLE 1. REVISIONS TO ESTIMATES OF EXPOSED POPULATIONS 

Distance from 

plant center (km) 

Secondary 

0.20 -

0.35 -

0.50 -

0.65 -

0.80 -

0.95 -

1.10 -

1.25 -

1.40 -

1.55 -

1.70 -

1.85 -

Totals 

Smelters 

0.35 

0.50 

0.65 

0.80 

0.95 

1.10 

1.25 

1.40 

1.55 

1.70 

1.85 

2.00 

Battery Plants 

0.10 -

0.25 -

0.40 -

0.55 -

0.70 -

0.85 -

Totals 

0.25 

0.40 

0.55 

0.70 

0.85 

1.00 

Total 

population 

1,792 

3,455 

10,355 

10,446 

8,608 

10,083 

9,687 

9,764 

10,870 

11,975 

13,080 

14,186 

114,301 

29,652 

52,924 

62,197 

54,470 

61,742 

61,015 

322,000 

Children 

191 

368 

1,102 

1,112 

916 

1,073 

1,031 

1,039 

1,157 

1,274 

1,392 

1,510 

12,165 

3,156 

5,632 

6,619 

5,797 

6,571 

6,494 

34,269 

Sensitive 

Pregnant 

women 

30 

58 

174 

176 

145 

170 

163 

164 

183 

201 

220 

239 

1,923 

499 

891 

1,047 

917 

1,039 

1,027 

5,418 

a 

groups 

Adult 

men 

155 

299 

895 

903 

744 

872 

837 

844 

940 

1,035 

1,131 

1,226 

9,880 

2,563 

4,574 

5,376 

4,708 

5,337 

5,274 

27,832 

Populations of sensitive groups were derived form the total estimate and 

relative population group sizes from the lead criteria document. 
P.4 

/ k ALLIANCE 

Technologies Corporation -3-

TABLE 2. REVISED LIST OF SECONDARY SMELTERS 

Plant name 

Alco Pacific 

Exide 

East Penn 

Exide 

General Smelting and Refining 

GNB 

GNB 

Gopher 

Gulf Coast Lead 

Interstate Lead Co. 

Master Metals 

Pacific Chloride Metals 

Refined Metals 

Refined Metals 

Ross Metals 

Roth Brothers 

RSR 

RSR 

RSR 

Sanders Lead 

Schuylkill Metals 

Schuylkill Metals 

Standard Industries 

City 

Gardenia 

Dallas 

Lyons Station 

Reading 

College Grove 

Frisco 

Los Angeles 

Eagan 

Tampa 

Leeds 

Cleveland 

Columbus 

Beach Grove 

Memphis 

Rossville 

Syracuse 

Indianapolis 

State 

CA 

TX 

PA 

PA 

TN 

TX 

CA 

MN 

FL 

AL 

OH 

GA 

IN 

TN 

TN 

NY 

IN 

City of Industry CA 

Middletown 

Troy 

Mound City 

Baton Rouge 

San Antonio 

NY 

AL 

MO 

LA 

TX 
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f< ALLIANCE 

JFjMp^p^ Technologies Corporation -4 -

Table 3 compares the three population estimates. Data presented for the 

Alliance 1987 estimate incorporate the revisions discussed above. Because the 

TRC estimate addressed only children, the comparison is made on this basis. 

The estimates differ considerably for secondary smelters and battery plants, 

with the largest difference, a factor of 8, between the Alliance 1985 and 1987 

estimates for secondary smelters. Two major factors present themselves as 

possible explanations for the discrepancies. First, different analytical 

methods were used in each of the three studies, and, second, the three analyses 

covered different sets of plants. Changes in plant lists arose both as a 

result of updates made to the lists and as a result of plant openings and 

closures between 1983, when plant lists were developed for the first Alliance 

estimates, and 1987. 

Changes in plant lists affect the population estimates both by virtue of the 

numbers of plants covered, and because of population density differences from 

plant to plant. The difference in population from the Alliance 1985 and 1987 

secondary smelter estimates is a factor of 4.5 on a per plant basis, compared 

to the factor of 8 cited above for the straight population estimates. 

The factor of 4.5 must result from a combination of the differences between 

population densities among the plants covered in the two analyses, and the 

differences in methodology. It is difficult to quantify the impact of either 

of these factors. Based on our SHEAR results for secondary smelters and 

battery plants, I was able to compare the relative population densities for 

cities on the 1983 secondary smelter list use in the first Alliance analysis, 

and the latest smelter list used in the TRC analysis and our most recent 

analysis. The difference in population density between cities on only the 1983 

list, and cities on only the latest list was a factor of 3.8. Because SHEAR 

was not rerun for all smelters on the 1983 list, the figures for the 1983 list 

are based on incomplete samples. Data were only available for 19 of 42 

locations. But the above list indicates that the population density 

differences could account for a substantial difference in the population 

estimate. In fact, population density in individual cities ranged over 2 

orders of magnitude. 

The impact of methodology can be isolated by studying the estimates for primary 

smelters and refineries, since list of primary smelters and refineries changed 

the least. The difference between the TRC estimate and the 1987 Alliance 

estimate for primary smelters, which are based on identical plant lists, is 

only 3 percent on a per plant basis. The 1985 Alliance estimate, which 

includes the closed Bunker Hill primary smelter, differs from the other two 

estimates by 23 percent on a per plant basis. 
P.6 

/ * ALLIANCE 

Technologies Corporation -5-

TABLE 3. COMPARISON OF POPULATION ESTIMATES 

Primary Smelters/Refineries 

Number of plants 

Children 

Children per plant 

Density—children/km 

—people/km 

Secondary Smelters (2 km) 

Number of plants 

Children 

Children per plant 

Density—children/km 

—people/km 

Battery Plants (1 km) 

Number of plants 

Children 

Children per plant 

Density—children/km 

—people/km 

(5 km) 

TRC 

(1986) 

6 

15.0 

2500 

31.9 

23 

19.7 

857 

68.3 

98 

15.8 

175 

51.4 

Alliance 

1987 

(revised) 

6 

14.6 

2433 

31.1 

289 

23 

12.2 

635 

54.6 

508 

87 

34.3 

394 

125.4 

1167 

Alliance 

1985 

7 

21.0 

3000 

38.2 

364 

60 

187.3 

3122 

248 

2387 

132 

25.0 

189 

60.3 

579 
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#4 

#4f4 ALLIANCE 

#^^ 4 Technologies Corporation • 6-

Because of limits to the resolution of both HEM-SHED and HEM-SHEAR (determined 

by the size of census enumeration block groups) both models would lose accuracy 

as the study area is decreased. Therefore, secondary smelter estimates would 

be less accurate than estimates for primary smelters, and estimates for battery 

plants by HEM would be the least accurate. 

In summary, it is difficult to pinpoint the source of the differences among the 

three population estimates. For the largest discrepancy, in the case of 

secondary lead smelters, a large portion of the discrepancy can be explained by 

changes in the location and size of the plant population as a whole between 

1983 and the present. However, a residual difference of at least 25 percent 

remains that must be attributed to uncertainties in methodology. In fact, 

given the resolution of SHED and SHEAR, accuracy of these methods at scales of 

1 and 2 kilometers is probably no better than plus or minus 50 percent. 

However, the accuracy of the TRC analysis is also subject to limitations. As 

noted above, the TRC analysis was based on a survey of emission sources. 

Response to the survey was 100 percent for primary smelters, but only 50 

percent for secondary smelters and battery plants. In addition, methods used 

by the individual plants to develop population counts are undocumented and 

their accuracy is unknown. 

The 1987/88 SHEAR estimate is similar to the TRC estimate for primary and 

secondary smelters, but differs by a factor of two for battery plants. This 

difference, while substantial, is probably within the limits of accuracy of the 

methods. (Coincidentally, the 1985 SHED estimate is very similar on a perplant basis to the TRC estimate.) A reasonable estimate of population would 

probably be an average of the counts obtained by the two methods, HEM modeling 

and plant surveys. The 1987 SHEAR modeling results should be used in place of 

the 1985 SHED results. It is not possible to determine which of these two 

models gives a better population estimate, but the 1985 results (SHED) should 

be discounted because of the age of the plant lists used to produce them 

(1983). 
P.8 

Xk ALLIANCE 

#jMM 4 Technologies Corporation -7-

REFERENCES 

Memo for R. Hill and W. Battye, Alliance Technologies Corp., to J. Haines 

and D. Sledge, Ambient Standards Branch. Estimation of Populations Living 

Near Major Lead Emission Sources. October 9, 10987. 

Memo from W. Battye, Alliance Technologies Corp. to J. Haines and J. 

Cohen, Ambient Standards Branch. Estimated Numbers of Children Residing 

Near Lead Point Sources. April 6, 1985. 

Hoffnagle, G.F., and W.A. Klinger. Exposure to Airborne Lead from 

Stationary Sources: an Evaluation of Proposed National Ambient Air 

Quality Standards for Lead. Prepared by TRC Environmental Consultants for 

the Lead Industries Association. March 1986. 

Air Quality Criteria for Lead. 

EPA-600/8-83-028. 1986. 

U. S. Environmental Protection Agency. 

Letter from R. Putnam, Putnam Environmental Services, to J. Haines, 

Ambient Standards Branch. List of Secondary Lead Smelters. October 8, 

1987.