Technical and Regulatory Guidance for In Situ Chemical ... - ITRC

APPENDIX D – Cost Estimates
Although many of the costs for ISCO are site-specific, generic cost equations may be used to at least
calculat e t he chemical costs associated with ISCO treatment based on site-specific soil and
groundwater carbonate and COD values. These equations can provide a first step in evaluating if the
cost of ISCO remediation is cost-prohibitive based merely on the cost of the treatment chemicals.
However, in using these equations, one must keep in mind that the chemical costs typically constitute
between 15 to 30 percent of the total remediation life-cycle costs. The equations for estimating the
ISCO treatment chemical costs are summarized below, and are based on the following assumptions:
One mg/kg COD calculated by chromic acid titration is equivalent to a 2.5 mg/kg KMnO4
demand
based on carbon to carbon dioxide stoichiometry;
One mg/kg COD calculated by chromic acid titration is equivalent to 2.1 mg/kg H2O 2
demand based
on carbon to carbon dioxide stoichiometry;
The specific gravity of 11% hydrogen peroxide is 1.1;
Carbonate/bicarbonate concentration refers to total calcium carbonate alkalinity as determined by
acid titration to a pH value of 4.0;
1.07 grams of sulfuric acid neutralizes one gram of calcium carbonate;
3
The soil density is 1.85 g/cc (1,400 kg/yd );
The ferrous iron demand is 0.5 percent of the total peroxide demand;
Ferrous sulfate heptahydrate is comprised of 20 percent ferrous iron;
The cost of hydrogen peroxide is $0.25/lb (1999 vendor quote);
The cost of potassium permanganate is $1.60/lb (1999 vendor quote);
The cost of sulfuric acid is $0.10/lb (1999 vendor quote); and
The cost of ferrous sulfate heptahydrate is $1.00/lb (1999 vendor quote).
Chemical cost per cubic yard of subsurface treatment zone using Fenton's oxidation:
3 3
H2O 2
($/yd ) = [(COD
gw/1.85)x(.25) +(COD
soil)x(.75)]x(2.1 mg H2O 2/g soil) x (1,400 kg/yd ) x (1
lb H2O 2
/453,600 mg) x ($0.25/lb)
= [(COD
gw /1.85)x(.25) +(COD
soil )x(.75)]/617
3 3
H2SO 4
($/yd ) = [(Alkalinity
gw/1.85)x(.25) +(Carbonatesoilx(.75)]x (1.07) x (1,400 kg/yd ) x (1 lb
H SO /453,600 mg) x ($0.10/lb)
2 4
= [(Alkalinity
gw/1.85)x(.25) +(Carbonate
soil)x(.75)]/3028
3
FeSO
4
.7H2O ($/yd ) = [(H2O 2
costs)x(0.5)x($1.00/$0.25)/0.2]
Chemical cost per cubic yard of subsurface treatment zone using permanganate oxidation:
3
KMnO
4
($/yd ) = [(COD
gw/1.85)x(.25) +(COD
soil)x(.75)]x(2.5 mg KMnO
4/g soil) x (1,400
3
kg/yd ) x (1 lb KMnO
4/453,600 mg) x ($1.60/lb)
= [(COD
gw/1.85)x(.25) +(COD
soil)x(.75)]/81
Oz one is generated on-site from ambient air using an electrical discharge or similar means.
Therefore, the costs associated with its use include the purchase of the generating equipment and the
electricity required to operate it. Information on the cost of the generating equipment is included in
the Case Studies section of this document.
D-1