Section 14. LAND DISPOSAL
LAND APPLICATION OF LIQUID WASTE VIA
SUBSURFACE INJECTION
Sam W. Maphis, President
Briscoe Maphis, Inc.
Boulder, Colorado 80302
SLUDGE MANAGEMENT-A SERIOUS DILEMMA
The most serious technical problem we face today in wastewater treatment, one that wdl
require much additional research and development, is sludge handling and disposal. New federal regulations, with their primary aims to restore the chemical, physical and biological integrity of our nation's waters, coupled with our existing technical abdities to accomplish this
task, have created a tenfold increase in the quantity of sludge being produced at our wastewater facdities. The cost, and operational and environmental impact of handling and disposing
of this increase in quantities of material, present a serious ddemma.
LAND APPLICATION VS. TRADITIONAL METHODS
Of the three places to dispose of this material—land, air or water—the air and water alternatives have come under increasing criticism in recent years due to escalating cost and potential
environmental hazards. In the past, we have focused on short-range objectives and pursued
solutions in terms of disposing of a waste material. We are now learning that we must readjust this old throw-away attitude and examine a more balanced system, one which includes
disposal and beneficial reuse objectives.  Land application of these sludges is gaining renewed
support among wastewater facdity planners as an alternative to accomplish this balance over
the more conventional disposal techniques such as:
• Ocean Dumping: By barging or pipeline transport, this method of disposal is under
environmental pressure and appears to be fading fast as a feasible alternative.
• Incineration: Due to its high capital and operational costs and the reduced availability of energy, this method may be a less practical alternative given the limited
resources available to communities.
• Dewatering and Drying: This alternative is costly both in capital and in operation.
Moreover, it does not encourage a beneficial use of the waste material.
LAND APPLICATION-DISPOSAL BENEFICIAL REUSE
Therefore, the trend today is leaning toward land application of the undewatered liquid
sludge. Too often no attempt is made to dispose of sludge by integrating the material into the
natural system. Consequently, much of the conventional disposal technology represents a
nonbeneficial use of this potential resource.  Land disposal offers a technology for use of an
"out-of-place" resource, thus providing economical and beneficial solutions to the waste disposal problem. A real technical challenge and a worthy goal is using this material at locations
within our urban setting, thus minimizing transportation cost and at the same time receiving a
benefit.
SUBSURFACE INJECTION-ADVANTAGES CONVENTIONAL LAND APPLICATIONS
Subsurface injection offers an efficient alternative and solution to the many objections to
land application. Subsurface injection has several advantages over other sludge handling technologies:
• Capital outlays for costiy dewatering equipment, dryers, incinerators, etc., are avoided.
Capital costs for subsurface application are concentrated in the acquisition of land,
a nondepreciating asset. With proper management and dependence on local goals/
objectives, it is often possible to add value to land used as a disposal site.
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