Photo 1. SCAT 481 Turner at Milwaukee CDF, 8/98

Technical Note DOER-C5

September 1999

SCAT 481 Turner at Milwaukee CDF, 8/98

Photo 1.

material from the surface of the CDF was excavated and moved to the treatment area on the CDF.

A mat of wood chips (25 cm thick) was laid down over the treatment area. Additional wood chips

were placed in the windrow locations to provide a dredged material:wood chip ratio of 4:1 (vol:vol).

Dredged material was then placed on top of the wood chips in the windrow locations and mixed

with the wood chips using the SCAT 481 Turner. Figures 3 and 4 show windrow cross sections

before and after mixing. The windrows are 150 m long.

Windrows were constructed during the late fall of 1997, but the turning operation could not be

initiated until the third week of July of 1998 because the turner was not available until then. The

thick vegetative cover that developed during the spring of 1998 demonstrated the potential of this

material for growing plants. The SCAT Turner 481 had no difficulty with turning this vegetation

into the dredged material/wood chip mix (Photo 2). Additional wood chips were mixed into the

windrows using the SCAT 481 Turner, and thereafter, the SCAT 481 Turner was used to turn

the dredged material/wood chip mix on a weekly basis. Within a month, the weekly mixing cleared

the windrows of plants. Debris such as tires and small stones (5-cm diam and 20-cm length) were

no problem for the SCAT 481 Turner. Items such as these are picked up by the turner; as they

bounce on the belt, they work themselves to the side where they fall off. Heavier debris that the

turner could not pick up, such as large chunks of concrete, had to be removed either manually or

with a front-end loader. The SCAT Turner takes about 30 min to make two passes on each

windrow for a total work time of about 2 hr. (The turner leases for $5,000.00 per month.) At the

end of turning, the windrows were well mixed and well aerated.