Wastewater Treatment for Little Mountain Service Area

Team: Tamma Bahr, Ella Leonelli, Sarah Miller, Jacob Ramsey, Jerron Stead, and Jessica Watkins

Sponsor: Carollo Engineers

Introduction/Summary

LMSA is expecting development, and the current treatment system willnot be able to treat the inflow expected from the population growth. Theteam has designed a mechanical wastewater treatment plant to replacethe current treatment system with methane recovery, power generationand the option for expansion

Background

  • Currently operates wastewater collection system, lift stations, and a three-cell lagoon system
  • Current population is 4,000 and is expected to grow to 42,000 in the next 5-10 years
  • Area is to be adopted by the Utah Inland Port Authority
top down view of the site map

Design Criteria

The design objective for this project is to evaluate LMSA’s availablealternatives to treat the anticipated flow from the new development.

Average Flow 5.2 MGD
Maximum Daily Flow 10.4 MGD
Total Phosphorus 1 mg/L
Biological Oxygen Demand 25 mg/L
Total Suspended Solids 25 mg/L
E.coli (organisms) 126/100 mL

Alternatives

Alternatives:

  • Do nothing
  • Send wastewater to Weber
  • Type 1 reuse
  • Type 2 reuse
  • Treat for purpose
  • Potable

Criteria:

  • Economics: low cost is important due to the number of people currently in the area
  • Environmental: area will be the West Weber Industrial District and Renewable Energy Hub
  • Adaptability: rapid development makes adaptability important for plant operation

Alternative Design

The selected alternative was type 2 reuse, with the lowest cost, goodadaptability, and reasonable environmental friendliness. Type 2 reusestandards are almost identical to Utah effluent standards, which makesthis design more adaptable, given that the initial water reuse permit wasdenied.

Design flow diagram

Our team had the honor of competing in the state competition. We werethen selected to present at the student design competition at WEFTEC,an international industry conference.

group 1
group 2
group 3
group 4

Reuse

reuse

Anaerobic digestion is used to producemethane, which fuels generators thatpower part of the mechanical treatmenplant.

LMSA requested that we consider water reuse in our alternatives. Ourdesign meets Utah regulations for water reuse. However, the submittedpermit was not approved, and new permits will not be approved.

Because aluminum is toxic to plants, the sludge from this treatment plantwill be dewatered on two parallel lines. This will allow for the digestedsludge to be composted and used as fertilizer, while the nutrient sludge willbe landfilled.

Cost Estimate

Operation and Maintenance cost graph Capital Cost graph

Cost estimates are based off the cost ofstandard plants with adaptation fornutrient removal, using a power seriesregression. The loan was assumed to be80% of cost, 20 years, and 1% interest.

Capital cost $52 million
Annual O&M $6.2 million
Cost during repayment $4.51/1000 gal
Cost after repayment $3.29/1000 gal

References and Acknowledgements

  • Team members: Tamma Bahr, Ella Leonelli, Sarah Miller, JacobRamsey, Jerron Stead, Jessica Watkins
  • Additional WEAU team members: Sterling Brinkerhoff, Donald OlsenMentors: Ryan Bench, Jade Echard, Matt Farley, Jayesh Charthal,Madeline Tennant
  • Teachers: Ryan Dupont, Austin Ball
  • Organizations: Water Environment Assocation of Utah, LittleMountain Service Area, Ted Miller Associates