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Learn about the Metropolitan Water Reclamation District of Greater Chicago and their innovative process for producing Class A biosolids. Explore the evolution of solids management, the benefits of biosolids utilization, and their PFRP-equivalent certification.
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Metropolitan Water Reclamation District of Greater Chicago Producing Class A Biosolids The Chicago Way – A Unique PFRP Equivalency Process Dr. Lakhwinder S. Hundal Sr. Environmental Soil Scientist EM&R Department Metropolitan Water Reclamation District of Greater Chicago NWBMA Conference, Chelan, WA Sept 19 – 21, 2010
About The MWRD Founded in 1889 to protect water quality of Lake Michigan Services Cook County Illinois including city of Chicago and 125 suburban communities Service area covers 875 sq. miles and includes 5.5 million people + industry equivalent to 5.7 million people Operates seven water reclamation plants handling daily flow of 1.5 billion gallons – Fill 450 acre swimming pool 10 ft. deep daily Produces ~180,000 dry tons biosolids annually– Takes ~ 15,000 semi trailers to haul annual production It is a Big Pile of Poop!!
Evolution of Solids Management … • Solids management was not an issue in 1889 • Became a necessity in 1920s • Constructed Imhoff Tanks • Calumet WRP in 1922 • Stickney WRP in 1930 • Imhoff tanks provided sludge storage and digestion
Evolution of Solids Management … contd. • Installed lagoons in 1937 to handle IHS, WAS, & PS • Long-term storage discontinued in 1970s • Due to horrific odor and public outcry • Dwindling lagoon capacity Disposal in lagoons – Not a good option
Evolution of Solids Management … contd. • Evaluated feasibility and economics of three alternatives: • IHS drying on sand beds • Separate digestion in heated tanks and drying on sand beds • Mechanical dewatering IHS, heat drying & incineration • Adopted the 3rd alternative; built a mechanical dewatering facility, a heat drying, and an incineration plant in 1937
Era of NitroganicTankage • Sold as: • Bulk to citrus farmers in Florida • In bags as Nitrorganic Tankage • Heat drying abandoned in 1981 • Energy shortage in 1979 • O&M costs too high • Environmental awareness
Era of Nu Earth (1930s – 1987) • Air-dried Imhoff sludge “Give Away” program • Used in home gardens as a “soil builder” • Public loved it Promoting Nu Earth
Demise of Nu Earth • Discontinued in 1987 due to: • High metal content – Cd > >300 mg/kg • Bad press • The District commit to distribute biosolids only under controlled practice
Using Liquid Sludge For Reclamation of Strip-Mined Land “Prairie Plan” Fulton County, IL - 1971 Barging Liquid Sludge 200 miles Down the Illinois River to Fulton County Won the engineering award of 1974 – Competition was BART in San Francisco, CA and Sears Tower in Chicago
“Prairie Plan” Fulton County, IL • No biosolids to site since 2004 because: • Production of air-dried EQ biosolids • Ability to find local outlets for EQ biosolids • Plain economics – Cost savings • Air-dried EQ biosolids readily accepted as topsoil substitute for daily and final covers in municipal landfills • Increased local demand for air-dried EQ biosolids
Common Beneficial Uses • Soil Amendment / Soil Conditioner • Improve soil fertility and soil tilth • Substitute for Commercial Fertilizers • Top dressing golf courses • Fertilizing agricultural crops • Substitute for Topsoil • Construction of recreational facilities • Landfill Cover – Daily and final cover
Cinder Ridge Golf Links Area: 100 acres, 18-hole courseQuantity = 500 – 600 ton/yrSavings: >$25,000
Harborside International Golf Course • 453-acre site including two 18 hole courses and golf academy • Over 500,000 dry tons of District’s biosolids used in final cover of landfill • Hosted Georgia-pacific senior PGA pro Am and SBC senior open • Voted third best municipal golf course in USA by the golf week magazine ?
Chicago River Sculpture Park in Chicago Area: 4 acresApplication rate = 650 ton/acSavings: >$75,000
BIOSOLIDS Utilization SUMMARY Farmland (80%) Golf Courses, Parks (10%) Daily & Final Cover (7%) Landfill Co-disposal (3%)
Major Initiatives Undertaken to Attain Current Program • PFRP-Equivalent Class A Certification • Increase Research and Demonstration Activities
PFRP-Equivalency Certification • After 1993 the District started evaluating its solids processing trains for Class A PFRP • Evaluated pathogen analyses of 344 samples from 1991-1996 monitoring • Filed a petition to USEPA’s Pathogen Equivalency Committee • Pathogen analysis on additional 1,400 samples • Stickney and Calumet WRPs processing trains granted Class A PFRP equivalency in July 2002
PFRP-Equivalent Codified Operation • Anaerobic Digestion • Temperature – 95ºF minimum • Retention time – minimum 20 days • Centrifugation (High Solids Processing Train) • Solids content – 25 to 30 percent • Lagoon Aging • Holding time – 18 months minimum after last addition • Air-Drying • Agitation frequency – 3 to 4 times per week • Solids content – 60 percent minimum
PFRP Certification Requirements • Demonstrate compliance by testing 12 samples per year for helminth ova & virus • Report data semi-annually • Annual PFRP compliance audit • Cost of helminth & virus testing for each Project • Eliminates logistics associated with 4-6 wk turnaround for helminth ova testing • Good PR Benefits
Lessons Learned Good working relationship with state and federal regulators Establish good public relations program Low tech processing trains very effective in pathogen reduction
Lessons Learned Codify PFRP-equivalent processing to allow more operational flexibility Modify processing trains by blending to with other materials to address odors, salinity, and excess nutrients Air-drying and stockpiling subject to will of “Mother Nature” and can severely affect coordinating timing of production and demand