Agenda - Council - 01/13/1981 - Laserfiche WebLink

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- 24 - DEFINITIONS 1. Sludge - the byproduct from the treatment of domestic and industrial sewage. 2. Agronomic rates - the spreading of sludge such that it will supply the nitrogen requirement of the crop grown without exceeding toxicity limits from heavy metals. 3. Non-agronomic rates - the disposal of sludge at large rates far in excess of the requirement for plant growth. ~. Grit - large heavy material, such as sand and rocks, removed from sewage by reducing the velocity of the sewage. 5. Screenings - the material, such as sticks and rags, removed from 4It sewage by bar screens with 2 inch openings. 6. Incinerator ash - the solid residue remaining after the burning of sewage sludge. 1. Leachate - the water that will percolate through the landfill or landspreading site which may pick up contaminents contained in the ash, sludge or soil. 8. Primary sludge - easily settled solid organic materials contained in sewage. 9. Secondary sludge - harder to settle organic material and biological solids produced in the treatment of sewage. 10. Thickened sludge - the concentration of sludge by gravity ~ settling. Usually the solid content is 6-10 percent. 11. Unthickened sludge - raw primary and/or secondary sludge. 12. Thickeners - tanks that are used to thicken the sludge. 13. Anaerobic digestors - large enclosed tanks where microorganisms grow in the absence of oxygen, which consumes the sludge producing methane gas and stabilizes the sludge (reducing the amount of pathogens). 1~. Lime stabiliza~ion - chemical conditioning or sludge to reduce the amount of pathogens. 15. Industrial Pretreatment Program - A program of the MWCC which will require industries that discharge into the MWCC's system to remove pollutants that could contaminate the sludge or affect the water Quality of the receiving water. 16. Development Program - A capital improvement program prepard by the MWCC in accordance with Council Policy Plans.