|
130
<br /> CommunitySmall Collection Construction Costs
<br /> Table 15.WERF Wastewater Planning Model:Effluent and Grinder Sewers(200 EDU).
<br /> Cost Description Effluent Sewer Grinder Sewer
<br /> Cost of collection network $516,179 to $774,268 $525,950 to $788,925
<br /> Installation cost of on-lot $2,625 to $3,938 $4,291 to $6,436
<br /> Total installation cost $1,041,232 to $1,561,848 $1,384,090 to $2,076,135
<br /> Total system cost/connection $5,206 to $7,809 $6,920 to $10,381
<br /> Annual on-lot 0&M $63 to $78 $224 to $336
<br /> Table 16.WERF Wastewater Planning Model:Vacuum and Gravity Sewers(200 EDU).
<br /> Cost Description Vacuum Sewer Gravity Sewer
<br /> Cost of collection network $2,120,188 to $3,180,283 $3,092,330 to $4,638,494
<br /> Installation cost of on-lot $3,761 to $5,641 $726 to $1,088
<br /> Total installation cost $2,120,188 to $3,180,283 $4,638,494 to $5,001,322
<br /> Total system cost/connection $10,601 to $15,901 $23,192 to $25,007
<br /> Annual on-lot 0&M Maintained by utility $16 to $24
<br /> Conclusion
<br /> Small communities face enormous challenges when constructing and maintaining wastewater infrastructure. Conventional collection system tech-
<br /> nologies—when applied to small, rural communities—typically result in costs that exceed affordability thresholds and ultimately require grant
<br /> subsidies to attain reasonable user rates.Without economies of scale, operational budgets are often underfunded, ultimately jeopardizing system
<br /> sustainability and threatening permit non-compliance.
<br /> Alternative collection systems were developed and designed to avoid the shortcomings associated with applying gravity sewers to small communi-
<br /> ties. Historically, effluent sewers($9,702/connection) have resulted in an average cost savings of$6,692 (41%),when compared to gravity sew-
<br /> ers($16,394/connection).The monthly debt retirement savings—per connection—equates to$28.44/month/connection (30 years,3%),well
<br /> above the estimated uniform equivalent monthly 0&M costs for effluent(Orenco) sewers of$7.05/month/EDU.
<br /> With increasing energy costs, uncertainties about future fossil fuel supplies, and increasing awareness of the impacts of greenhouse gas emis-
<br /> sions,the efficient management of energy is now of greater concern among both private and public entities." Orenco effluent sewer systems are
<br /> largely immune to extraneous flows, resulting in a major cost savings, both capital and electrical, at the WWTP. Orenco effluent sewer systems, by
<br /> design,also enable simpler operations, less expensive operational equipment,and less reactive maintenance with respect to immediate response
<br /> time relative to individual onsite problems versus gravity or lift station problems.
<br /> NFS-EFS-CC-1 ®2014 Orenco Systems®Inc.
<br /> Rev.1.6,©08/14
<br /> Page 12 of 13
<br />
|