In-Situ Treatment Calculator

Calculate injection well spacing, reagent volumes, and costs for in-situ chemical oxidation or reduction.

Treatment zone length (m)

Treatment zone width (m)

Treatment depth (m)

Effective porosity

Contaminant in groundwater (mg/L)

Radius of influence (m)

Stoichiometric ratio (kg/kg)

NOD multiplier

Reagent cost ($/kg)

Tab to move between fields

Well spacing (m)

4.24

Number of injection wells

Total reagent (kg)

675

Treatment volume (m³)3,000

Pore volume (m³)900

Contaminant mass (kg)45

Reagent per well (kg)16.9

Solution per well (gal)149

Reagent cost ($)$2,700.00

How to Use This Calculator

Enter treatment zone dimensions (length, width, depth in meters) from the site plan.
Set effective porosity and the contaminant concentration in groundwater (mg/L).
Review the calculated pore volume and total contaminant mass to size the treatment system.
Check recommended well spacing and total number of injection/extraction wells.
Use total volume of reagent needed to prepare material orders and cost estimates.

How the result changes with Radius of influence (m)

Radius of influence (m)	Well spacing (m)	Number of injection wells	Total reagent (kg)
2.45	3.46	54	675
7.32	10.35	6	675
13	18.38	4	675
18	25.46	2	675

Treatment zone length (m): Length of the target treatment zone.
Treatment zone width (m): Width of the target treatment zone.
Treatment depth (m): Vertical extent of the contaminated interval.
Effective porosity: Fraction of soil volume that is pore space.
Contaminant in groundwater (mg/L): Average dissolved contaminant concentration in pore water.
Radius of influence (m): Effective reagent delivery radius per well. Sand 3-5m, silt 1-2m.
Stoichiometric ratio (kg/kg): kg reagent per kg contaminant. KMnO4 for TCE ~2.4, persulfate ~4.7.
NOD multiplier: Natural oxidant demand multiplier. Typical 3-10x stoichiometric demand.
Reagent cost ($/kg): Unit cost of chemical reagent. KMnO4 ~$3-5/kg, persulfate ~$1-2/kg.

Treatment volume (m³): Total volume of the treatment zone.
Pore volume (m³): Volume of groundwater in the treatment zone.
Well spacing (m): Center-to-center distance for injection wells (diagonal overlap pattern).
Number of injection wells: Total wells needed for grid coverage of treatment zone.
Contaminant mass (kg): Total dissolved contaminant mass in the pore water.
Total reagent (kg): Total chemical reagent mass including natural oxidant demand.
Reagent per well (kg): Chemical mass to inject at each well.
Solution per well (gal): Volume of 3% reagent solution to inject per well.
Reagent cost ($): Total chemical cost (does not include mobilization, wells, or labor).

Identify Input Parameters
4 parameters
Treatment zone length (m) = 30, Treatment zone width (m) = 20, Treatment depth (m) = 5, Effective porosity = 0.3 = 9 input(s) provided
Calculate Well spacing
Well spacing = roi * sqrt(2)
4.24 = 4.24
Calculate Number of injection wells
Number of injection wells = wellsAlongLength * wellsAlongWidth
40 = 40
Calculate Total reagent
Total reagent = stoichDemand * nodMultiplier
675 = 675
Calculate Treatment volume
Treatment volume = treatLength * treatWidth * treatDepth
3000 = 3000
Calculate Pore volume
Pore volume = treatVolume * porosity
900 = 900