Average person produces 1700 lbs of MSW per year Solid Waste Any unwanted material that is not liquid or gas 98.5% is from mining, oil & gas production, industry, sewage sludge and agriculture 1.5% is known as municipal solid waste (MSW) from homes and businesses (aka garbage) Average person produces 1700 lbs of MSW per year

How do we deal with solid waste? 1. Burn/Incinerate Advantages Reduced trash volume Less need for landfills Low water pollution Disadvantages High cost Air pollution (especially toxic dioxins) Produces a highly toxic ash Encourages waste production 16% of MSW is burned in mass-burn incinerators

2. Land disposal Sanitary landfill  solid wastes are spread out in thin layers, compacted and covered daily with a fresh layer of clay or plastic foam In modern landfills the bottom is covered with an impermeable liner to collect leachate Rainwater contaminated as it percolates through the solid waste Collected leachate is pumped from the bottom, stored in tanks and sent to a sewage treatment plant More than half of the MSW in the U.S. is buried in sanitary landfills

Methane produced by anaerobic bacteria must have a way to escape the landfill or be collected. Monitoring wells surround the landfill to check the groundwater and make sure no contamination is occurring. Some landfills collect the methane produced and use it to generate electricity  cogeneration

Hazardous Waste Any discarded solid or liquid that . . . . contains one or more toxic, carcinogenic, mutagenic, or teratogenic compounds at levels that exceed limits catches fire easily is reactive or unstable enough to explode or release toxic fumes is capable of corroding tanks, drums, or barrels

Official US definition does NOT include radioactive waste hazardous materials discarded by households mining and oil drilling wastes This means 95% of hazardous waste is not regulated by hazardous waste laws

80% of hazardous waste is incinerated How do we deal with hazardous waste? 1. Burn/Incinerate 80% of hazardous waste is incinerated

2. Detoxify * Bioremediation  using microorganisms and enzymes to convert toxic or hazardous substances to harmless compounds effective for organic wastes, pesticides, liquid fossil fuels, PCBs, and organic solvents * Phytoremediation  using plants as ”pollution sponges” to filter and remove contaminants effective for organic solvents, radioactive metals and toxic metals such as lead and mercury

3. Land disposal * Deep underground wells wastes are pumped under pressure through a pipe into dry, porous geologic formations far below aquifers * Surface Impoundments excavated depressions such as ponds or pits into which liquid hazardous waste are drained and stored * Secure landfill * Above ground buildings two-story buildings of reinforced concrete

Resource Conservation and Recovery Act Hazardous waste LAWS Resource Conservation and Recovery Act aka RCRA (RICK-ra) Requires the EPA to identify hazardous wastes and set standards for their management by states Firms that store, treat or dispose of more than 100kg (220 lbs) of hazardous waste per month have to have a permit Permit holder keep track of waste from point of origin to disposal facility

aka CERCLA or Superfund Act Comprehensive Environmental Response, Compensation, and Liability Act aka CERCLA or Superfund Act identifies abandoned hazardous waste dump sites and underground tanks leaking toxic chemicals protects and if necessary cleans up groundwater near such sites cleans up the sites when they can be found, requires responsible parties to pay for the cleanup the worst sites are put on a National Priorities List (NPL)

Brownfields are abandoned industrial and commercial sites that are in most cases contaminated