Industrial Laundry Facility
Western Washington
The project site is occupied by a large-scale commercial and industrial laundry facility. Uniforms, shop rags, and work area floor mats comprise a large portion of the items laundered. A Washington State “Dangerous Waste Book Designation” was completed to determine the toxicity criteria for 11 toxic metals and effect on the 96-Hour Standard Static Acute Fish Toxicity Test on composite samples of the bentonite clay pressed commercial laundry sludge waste. The plant generates about 1,500 pounds of pressed sludge cake every operational day and uses about 100 pounds of bentonite clay.
The pressed sludge waste originally generated at the facility was designated as a Washington State-Only Dangerous Waste; waste code WT02. The facility installed a new Electro/Hydraulic Sidebar Filter Press to treat process wastewater using bentonite clay to produce filter cake. The bentonite clay used is classified as a treatment binder which acts as a metal scavenger, coagulant, and flocculant.
The first objective of the sampling and testing program was to determine if the generated filter press cake meets the Washington State-Only Dangerous Waste “Book Designation” toxicity criteria for the generator-known 11 toxic metals. Washington accredited laboratory test results for the 11 toxic metals on the collected samples were designated using the ECOLOGY “Book Designation” procedure following Chapter 173-303-100 (5) (b) – Book Designation Procedure. The second objective was to determine if the generated waste meets the Washington State-Only Dangerous Waste Designation for the 96-Hour Standard Static Acute Fish Toxicity Test. The results of the fish bioassay test (Pass / Fail) were used to make the final determination to see if the waste designated as a Washington State-Only Dangerous Waste.
The sampling and testing confirmed that the generated commercial laundry bentonite clay pressed sludge waste cake did not designate as Washington State WT02 waste under the Washington State Dangerous Waste Regulations (Chapter 173-303).
The facility was able to get out of the dangerous waste classification and they realized a savings of $70,000 on an annual basis for sludge disposal. The facility also saved $20,000 a year from the ECOLOGY surcharge from the Large Quantity Generator (LQG) classification.
