Surface water. Surface water that infiltrates the cover soil can
increase the rate of waste decomposition and eventually cause
leachates to leave the solid waste and create water pollution
problems. This problem can be minimized by rejecting sites
containing surface water features, diverting upland drainage, and
designing facilities with sufficient grade and slope to allow surface
water runoff. Sites shall be selected on. the basis of a
geohydrological evaluation of surface water problems.
Terrain. A sanitary landfill can be constructed on virtually any
terrain; however, some land features require extensive site
improvements and expensive operational techniques. The best terrain
consists of flat or gently rolling land not subject to flooding.
While depressions such as canyons and ravines are more efficient than
flat areas, cover material may not be available. Also, special
difficulties may occur in depressions and control of surface waters
may be difficult. Such manmade features as strip mines, quarries,
and open pit mines can often be safely and economically reclaimed by
the government as sanitary landfills. Some offer excellent
protection against leachate pollution, while others require more
extensive improvements. Terrain features that shall exclude a site
for consideration include the following:
a. hilltops and other similar land forms
b. highly permeable and porous areas such as gravel beds
c. swamps and marshes
d. natural drainage channels
e. wildlife sanctuaries
g. land having karst features such as limestone formations which
can lead to the formation of sinkholes and depressions
h. steep slopes.
22.214.171.124 Hydrogeological Characteristics
126.96.36.199 Liner Systems: Soil and Membrane (Robinson 1986). Both the
need to protect the environment and regulatory agency requirements have
resulted in the installation of liners at the base of many landfills. The
liner's purpose is to limit the movement of leachate through the base of the
landfill and into the underlying formations. Many materials and techniques
have been tried in an effort to prevent leakage at a reasonable cost.
188.8.131.52 The liner must endure chemical and physical attack mechanisms.
Many chemicals found in leachate have the potential to damage liner materials.
Also, the liner must not fail structurally during installation or from the
strain of the solid waste.