Contents

F23 Exercise Set 5

LAST NAME, FIRST NAME

R00000000

Purpose :

Apply selected analytical models for reactive transport

Assessment Criteria :

Completion, results plausible, format correct, example calculations shown.

Problem 1 (Problem 11-1, pg. 594)

A contaminated site has been surveyed and a contaminated region \(100~ft. \times 150~ft. \times 15~ft.\) was delineated. The average concentration of total petroleum hydrocarbons (TPH) in soil is \(10,000~\frac{mg}{Kg}\)

Determine:

  1. The total mass of contaminants at the site in kilograms. Assume the soil has a specific gravity, \(SG _{soil} \approx 2.0\)

  2. Estimate total volume of petroleum hydrocarbons released assuming 50% of the hydrocarbins are lost to volatization, biodegredation, and dissolution (report the answer in gallons). Assume the hydrocarbons were gasoline with a constant specific gravity, \(SG_{\text{gasoline}} \approx 0.8\)

  3. Estimate the residual saturation of the hydrocarbon-soil system. Assume soil porosity is, \(n=0.35\)

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Problem 2 (Problem 11-2, pg. 594)

A sampling program at a Supermanfund site indicated the following DNAPL zones:

  • A pool of free phase DNAPL in a stratigraphic depression in an unfractured clay. The pool is 200 \(ft^2\) in area and 5 \(ft\) thick.

  • A zone of residual DNAPL extending directly underneath an old disposal pit 100 \(ft^2\) in area. The residual zone extends through the 5 \(ft\) thick unsaturated zone and 15 \(ft\) through the saturated zone until it reaches the DNAPL pool.

Supporting data:

Residual saturation in the unsaturated zone:

0.10

Residual saturation in the saturated zone:

0.35

Saturation in the free-phase zone:

0.70

Average porosity in water zone:

0.30

Determine:

  1. The total volume of DNAPL at the site

  2. The recoverable volume using ordinary pumping.

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Problem 3 (Problem 11-4, pg. 595)

Gasoline is found in a monitoring well with \(SG=0.80\). A total depth of 6 \(ft\) of gasoline is found in the well.

Determine:

  1. Estimated thickness of free-phase LNAPL in the formation.

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