Waste Source-seperation Versus Co-mingling: The Constast For Water Recycling

As the Indiana County Solid Waste Authority was developing its process for collecting and recycling materials for curbside collection in Indiana Borrough and White Township; we deliberated intensively on the issues associated with source-separation versus co-mingling.  The more the system depends on source-seperation, the more responsibilities are delegated to the household (decentralized); while the more the households are allowed to co-mingled the solid wastes, the more responsibilities are placed on some centralized processing system to recycle them.  Source-separation depends on the household to adequately expend the energy to prepare the materials for the next stage of recycling at the curbside.  Co-mingled systems ask the household to expend very little energy in material preparation.  Indiana's curbside system asks the household to separate newspapers in bags or bundles; and place co-mingled metals and glass in a 8 gallon recycling container.  I would classify it as a moderate source-separation system.  it permits a bit of commingling of different colored glass and the by-metals.  The packers then sort the comingled materials into seperate bins in the truck at the curb.  The center we operate permits NO co-mingling.  We ask drop-off participants to place seperated materials into designated containers for plastics (1 & 2), newspapers, metals, newsprint, magazines, clear glass, brown glass, green glass, grass clippings, corregated.  The decisions relating to where, when and who separates the recyclable materials has significant ramifications to the kind of processes and organization that is necessary, as well as the efficience and effectiveness of the operation (e.g., participation rates, volumes and the quality of the recycled materials).  The Indiana County Solid Waste Authority regularly revisits the issues of what we allow to be co-mingled and what must be separated, because they impact the processing system so profoundly.

Household water recycling (all water must be recycled - that's nature) faces similar issues and ramifications.  Traditionally households have employed systems that completely co-mingle all the househould liquid waste in a single stream.  Typically, the rural household employs a septic system that has a single 4" pipe into which the commode, sinks, laundry and other water sources in the house dump.  This pipe typically goes to a septic tank of several hundreds of gallons (tanks can be thousands of gallons), which then dumps to a leaching system for discharge into the environment.  Urban households connect their 4" co-mingled pipe to a larger sewage piping network that pumps the effluent to a large sewage treatment facility, which usually discharges the treated waste water into a nearby waterway.  The idea of source-seperation for household water systems has not really been considered very seriously.  The traditional technology assumes it is best to co-mingle a concentration; and treat the mixture in a centralized manner, then dilute the effluent.  Not much is expected of the household except the building of massive treatment facilities, paying to keep them running, and acceptance the dilution by existing wayerways is effective.  The assumption is that co-mingling is convenient, economical and environmentally sound!!!

However, if we begin to think about the possibilities regarding decentralized source-seperation for household waste water, many new ideas arise, just as it has in the solid waste recycling arena.  Some of these ideas may be more economical, convenient and environmentally sound.  Once we begin to imagine the aspects of separating the different waste water streams in the typical household (commode, shower, kitchen sink, laundry and lavatory), a whole new realm of processing and recycling opportunities emerge to be considered.  For instance, the shower provides an interesting type of waste water; that has a variety of characteristics and features  (it's warm, it has unique types of impurities, it has it's seperate drain) that can create specific recycling opportunities, and an array of processing possibilities for recycling water never really considered when the extreme co-mingling approach dominates thinking.  Begin to imagine the opportunities available when you decide to deal only with recycling shower water (source-seperation to the extreme); then imagine doing the same for the commade, the kitchen sink and so froth - I am.