Table 1. Example of Dredged Material and Blend Metal Concentrations, mg/kg

Technical Note DOER-C6

May 1999

Cooperating Company

Aspect of Manufactured Soil

Reconditioned biosolids from cow manure

BION Technologies, Inc.*

Formulation and blending equipment

Recycled Soil Manufacturing

Technology (formerly Terraforms)

Reconditioned biosolids from sewage sludge

N-Viro International

Bagged soil products

Scott and Sons Company*

Several bench-scale screening tests have been conducted using uncontaminated dredged material

from Toledo Harbor, Ohio, North Blakeley CDF in Mobile, Alabama, and St. Lucie Estuary,

Florida; nutrient-depleted soils from Fort Drum; New York; sandy soil from the Herbert Hoover

Dike surrounding Lake Okeechobee, Florida, and contaminated dredged material from the New

York/New Jersey Harbor-Newtown Creek site (Lee et al. 1998; Lee and Sturgis 1996). These

screening tests have been successful in determining the optimal percentages of dredged material,

cellulose, and biosolids to manufacture a fertile soil product. Manufactured soil using uncontami-

nated dredged material can potentially be used without restrictions as topsoil, while artificial soil

manufactured from contaminated dredged material may have restricted use (e.g., potential cover

for landfills, superfund sites, and reclamation of mineland) depending on the level of contamination

and the potential for contaminant release. The fertile soil product manufactured from dredged

material has been shown to contain lower levels of contaminants than the original dredged material

because of the dilution of material in the blend. Table 1 shows an example of a manufactured soil

blend that contains total metal concentrations below specified acceptable limits of the USEPA 503

regulations for biosolids-amended agricultural soils. Adding organic waste material to the manu-

factured soil product appears to bind and immobilize the contaminants reducing their bioavailabil-

ity. The quality of manufactured soil with respect to contaminant content will determine the final

use of the manufactured soil product.

Table 1

Example of Dredged Material and Blend Metal Concentrations, mg/kg

USEPA 503

Analytes

Dredged Material

Blend

Regulation

1,752.0

514.0

2,800.0

Zinc

39.0

37.0

7.9

Cadmium

231.0

300.0

Lead

617.0

1,500.0

393.0

Copper

1,172.0

140.0

Chromium

377.0

1.3

17.0

Mercury

18.4

6.1

Silver

12.5

41.0

Arsenic

33.5

<0.3

Beryllium

<0.6

95.0

420.0

Nickel

297.0

10.3

2.1

Antimony

3.3

Selenium

3.2

<1.6

Thallium

<2.8

BENCH-SCALE SCREENING TESTS: A specific blend (e.g., x1 percent dredged material, y1

percent cellulose, and z1 percent biosolids) can be prepared by mixing predetermined volume

percentages of cellulose, biosolids, and dredged material. Different blends are made by decreasing

the volume percentage of dredged material and increasing the appropriate volume percentage of

cellulose and biosolids. For the manufactured soil technology to be successful, the recommended