Environmental Science
Name: _______________
Lab: Not in My Backyard
Introduction
A landfill is an area where solid waste is placed and covered daily. As population size and
resource use increase, many communities are running out of places to put their garbage.
In this lab, you will first construct a model landfill to learn of its components. The class will
then try to determine the best location for a new landfill in Yoretown.
Procedure
Construction of Model Landfill
1. Obtain a plastic planter. Line the planter with a plastic sheet or pat out clay into a thin
layer like a piecrust and place it along the bottom.
2. Attach a piece of nylon stocking to one end of plastic aquarium hose with a rubber
band. Put the covered end at the bottom of your landfill (on top of the clay or plastic). This
represents a monitoring well.
3. Cut your trash into small pieces (about 5 cm square).
4. Alternately place trash and soil in planter until they are filled.
5. Place a plastic tray or cake pan under your planter. Water your landfill with 2 beakers
of water and wait several minutes.
a. Does any leachate come through the bottom?
b. If yes, describe the condition of the water.
c. Compare your results with other groups. Does plastic or clay make a better
liner?
6. Siphon (with blue pump) leachate from the monitoring well (hose) into a beaker.
Describe its condition.
Choosing a Site for a New Landfill
Yoretown has a waste disposal problem. The landfill used for the disposal of its solid waste
is near maximum capacity. Yoretown is so far from other disposal sites, it would not be
cost effective to have the community’s waste hauled there, although this remains an
option.
The city council and the solid waste district committee have identified four possible landfill
sites for a new county landfill as indicated on the map. The committee now seeks technical
advice on which is the best site.
Each group will be given specific information about one site. There is information below
on laws concerning the location of landfills. Evaluate your site based on the.
Landfill Siting Criteria
I. Hydrogeologic and surface drainage conditions:
1. Slope and terrain—These conditions can be important because they determine
how much earth must be moved to prepare the site and which direction the water
will flow off the site.
2. Soil Depth—shallow soils might not provide enough soil for daily cover of the
landfill. Some alternative daily covers, such as foam or a canvas blanket, could
possibly be used where appropriate soil would be difficult to obtain.
3. Soils permeability—The more permeable the soil, the more chance that rainwater
can collect in the landfill and become a carrier for leachate. The more impermeable
the soil layer at the bottom of the landfill the less likely leachate can seep trough to
the groundwater.
4. Bedrock—exposed bedrock can have pores or fractures that allow water to flow
through. Bedrock of a less porous nature lessens the chance for liquids to drain out
of the landfill.
5. Depth of uppermost aquifer system—Many farms and cities rely on ground water
for drinking water. Particularly important sources of groundwater are aquifers that
are wholly or partially saturated with water capable of storing, transmitting, and
yielding significant amounts of water. Sites close to an existing water well or well
field should be carefully evaluated. There should be at least 15 feet between the
bottom of a landfill and the uppermost aquifer.
6. Potential explosive gas migration—Over a period of time as waste decomposes
explosive gases such as methane can develop. Potential pathways for this gas to
migrate beyond the landfill include underground utility structures (sewers,
waterlines, electric cables), pipelines, oil wells, and gas wells, especially if these are
within 1,000 feet of emplaced solid waste.
7. Wells, mines and quarries—Wells, mines and quarries can be sources of
potential subsidence, especially if within 2000 feet of emplaced solid waste.
Subsidence can cause rupturing of the liner systems that are designed to prevent
leachate from reaching groundwater.
II. Impact on surrounding area
1. Access—Can trucks get to it? Can traffic be managed?
2. Zoning and land use—What is the land currently used for? Is the land valuable for
other uses? How will a landfill affect growth and development in general, and in
particular, at this specific site.
3. Location—Would its presence cause any detriment to an already established
cultural feature? (The new Gallia Academy High School cost 25-30 million dollars.)
4. Residence—No solid waste placement can be within 1000 feet of a domicile whose
owner has not consented to construction of the landfill.
5. Natural features—It is unacceptable to locate solid waste within 200 feet of a
stream, lake, or natural wetland unless proof of satisfactory diversion of stream or
protection of the lake is offered.
6. Nature preserve—It is illegal to place a landfill within 1000 feet of a nature
preserve.
7. Airports—If solid waste is placed within 10,000 feet of an airport serving turbinepowered aircraft or within 5,000 feet of an airport serving piston-type aircraft, the
permit application must demonstrate that the facility will not pose a bird hazard to
aircraft.
After the class discussion, answer the following questions:
1. Which site was chosen by the class and why?
2. List 3 alternatives the town might consider before building this landfill.
3. What questions (list at least 3) do you have after doing this activity?