SITE DESCRIPTION

Technical Note DOER-C5

September 1999

and trace nutrients, and water is usually available on or near by CDFs. Keeping oxygen in abundant

supply, however, is a problem in dredged material because of the high biochemical oxygen demand

of the material and the slowness of diffusive oxygen transfer. Oxygen transfer can be enhanced by

the creation of biomounds (mounds or windrows of contaminated soil or sediment, mixed with a

bulking agent such as wood chips and often a biosolid, such as sewage sludge). Biomound

composting technology has been successfully used in Minnesota to treat petroleum-contaminated

soil for several years (Kamnikar 1996). Biomound-type composting is relatively inexpensive

compared with bioslurry, bioventing, and temperature-controlled composting technologies. There

is a potential, therefore, to cost-effectively enhance intrinsic bioremediation processes in

dredged material by improving oxygen transfer from the atmosphere using biomound composting

technology.

SITE DESCRIPTION: The 44-acre Jones Island CDF at Milwaukee, WI, was constructed in 1975

and is located in the south outer harbor (Figure 2). The CDF serves as a disposal facility for

maintenance dredged material that is unsuitable for open-lake disposal from both Milwaukee Harbor

and Port Washington Harbor, located 25 miles north of Milwaukee. The design capacity of the

Jones Island CDF is 1.2 million cubic meters (MCM) (1.6 million cubic yards, MCY). Until

recently, annual maintenance dredging quantities typically ranged from 38,000 to 73,000 CM

(50,000 to 95,000 CY). Completion of a storm-water interceptor system in Milwaukee in 1994

reduced annual dredged quantities to around 19,000 CM (25,000 CY). The remaining capacity is

325,000 CM (425,000 CY), and it is expected that the CDF will be filled in 20 years.

PROJECT OBJECTIVES: The short-term objectives for the Jones Island bioremediation project

are to reduce PAH concentrations to levels that will allow offsite beneficial use at the lowest costs.

The long-term objectives involve developing a cost-effective treatment train for handling and

managing dredged material and eventually creating a marketable product. Supporting objectives

for the Jones Island demonstration project are as follows:

Obtain cost and performance data to assist the Corps in developing management options for

contaminated dredged material.

Provide data of sufficient quality to make a determination with regard to offsite beneficial

use options for dredged material in the Jones Island CDF.

Test and evaluate an innovative piece of equipment for turning and aerating dredged material.

Table 1 lists PAH concentrations in surface material from the Jones Island CDF and State of

Wisconsin criteria for reuse. A specific objective of this project is to reduce the concentrations of

benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, dibenzo(a,h)anthracene, and indeno-

(1,2,3-cd)pyrene to meet Wisconsin's standards for beneficial use of industrial byproducts.

MATERIALS AND EQUIPMENT: Wood chips were provided by the Port of Milwaukee in

coordination with the City of Milwaukee right-of-way maintenance program. Wood chips facilitate

aerobic biodegradation of pollutants in the following ways:

Contain white rot fungi (very good at degrading complex organic compounds).