Memo RE Unrestricted Use for Stockpiled Soils

March 3, 2016 Southside East Brownfields Project
Approximately 20 acres between Roxboro St., E. Lakewood Ave., and E. Piedmont Ave.
Durham, Durham County, NC Brownfields Project # 16008-12-32
Memorandum To File –
Two stockpiles exist on the Property which are planned for transport to off-site locations. These
stockpiles are planned for transport to non-landfill sites to be used as “beneficial fill”. The Soil Calculator used in noted below the table. Sandy Mort, Brownfields Program’s Toxicologist and Risk Assessor, was approached by JDR in her office this same morning at about 08:30 to 9:00
AM. The following data was requested:
1. Are the “Non-Cancer” Risk summary calculations the same as the “Hazard Index” found
on the VISL Calculators, where the HI ≤1.0 for acceptable risk? The answer the “Non-Cancer” column was the Hazard Index.
2. Is the Cumulative Risk goal the same as in the VISL Calculator, where CR ≤ 1 E-04 for
acceptable risk, and the goal for CR is < 1.0 E-04. 3. Then looking at the table below, and having used the Residential Risk Calculator, and
having the HI < 1.0, and having the CR < 1 E-04, the soil could be used for all
applications. Sandy Mort then stated soil meeting those criteria, such as those in the table below, are suitable for “unrestricted use”.
RISK ANALYSIS FROM STOCKPILE SAMPLING REPORTS
SOUTHSIDE EAST BROWNFIELDS SITE
Durham, NC Large and Small Stockpile Sampling Results
Table Generated by J Rudder on 3/2/16
Sample Date
Cumulative
Risk Residential
Hazard
Index Residential
Large Stockpile Results
SS-1-1 Lg 12/1-4/2015 4.3 E-06 4.9 E-02
SS-1-2 Lg 12/1-4/2015 4.5 E-06 8.3 E-02
SS-1-3 Lg 12/1-4/2015 4.3 E-06 6.0 E-02
SS-1-4 Lg 12/1-4/2015 4.8 E-06 6.0 E-02
SS-1-6 Lg 12/1-4/2015 3.7 E-06 6.3 E-02
SS-1-15 Lg 12/1-4/2015 3.9 E-05 7.8 E-02
SS-1-18 Lg 12/1-4/2015 6.6 E-06 7.1 E-02
SS-1-22 Lg 12/1-4/2015 8.8 E-06 7.4 E-02
SS-1-23C Lg 12/1-4/2015 2.9 E-05 9.8 E-04
SS-1-23D Lg 12/1-4/2015 4.6 E-05 1.7 E-03
SS-1-24 Lg 12/1-4/2015 5.5 E-06 3.7 E-02
SS-1-26 Lg 12/1-4/2015 4.1 E-06 6.0 E-02
SS-1-28 Lg 12/1-4/2015 4.4 E-06 5.1 E-02
Small Stockpile Results
SS2-8 Smal 9/29/2015 1.9 E-05 7.5 E-02
The Soil Calculator was sent by Hanna Assefa via email on Feb. 15, 2016 and is entitled “IHSB-
Brownfields Residential Soil Risk Calculator FINAL (November 2015 RSL.xls)”.