1. Wastewater Pre-treatment System for Terrapin Beer Co.
Team Members: Ryan Brush, Kaitlyn Ruff, Justin Rey, Kevin Metz, & Veronika Crumpler
Faculty Advisor: Dr. Tom Lawrence
Introduction Financial Analysis
Site Selection
Sponsor/Client: Terrapin Beer Company
Decision Matrix
Conclusions & Recommendations
Founded in 2002, Terrapin Beer Co. is a stable landmark in the city of Athens, Georgia.
However, their large-scale brewing process has resulted in a significant waste stream
hazardous to the environment. Athens Clarke County will now begin to regulate and fine the
brewery if a solution is not found. The objectives of this design project were to determine the
most efficient and sustainable solution to pre-treat effluent to meet Athens-Clarke County
standards, maintain the aesthetics of the brewery, and determine actual sizing, location, and
design for the implementation of the chosen system within the Terrapin facility.
Process Flow Design
Terrapin Brewery Wastewater Pretreatment System Site
No Pre-
treatment
Aerobic Anaerobic Living
Machine
Criteria WF UW W UW W UW W UW W
Initial Cost 10 4 40 3 30 2 20 1 10
Operating Cost 8 1 8 2 16 4 32 3 24
Allows for Growth 5 4 20 1 5 3 15 2 10
Discharge Water
Quality
7 0 0 4 28 2 14 3 21
Aesthetics, odor 5 4 20 1 5 3 15 2 10
Public outreach,
local impact
3 0 0 2 6 3 9 4 12
Total, unweighted 13 12 17 15
Total, weighted 88 90 105 87
★ Dr. K.C. Das, Anaerobic Digestion Specialist, provided expertise in
designing the equalization tank and grit chamber.
★ Brian Hollinger, VP of Operations at Terrapin, provided valuable
information regarding the company’s current production rates and future
benchmarks.
★ Bob Salvatelli, Sustainable Water Representative, provided information
about a similar project at Emory University.
ACC Water Requirements Average Water Quality
BOD < 500 8357
TSS < 500 1888
Phosphorus < 15 44
Nitrogen < 100 160
● Anaerobic digestion is the least disruptive method of pretreatment and is
most advantageous financially
○ Biogas generation, while neglected in calculations, offers potential
renewable source of fuel
● Inconsistent flows create design challenge and warrant use of an
equalization tank
● A 24 hour composite flow measurement and effluent sample would yield
more accurate model for design
● Additional front end methods of solids removal could greatly impact quality
of wastewater
○ Screening wastewater before pretreatment
○ Decanting centrifuge for yeast recovery
Acknowledgements
Year BBL/year Anaerobic Aerobic No Pre-Treatment
2018 85,000 $3,196,628 $3,160,429 $3,132,915
2020 105,000 $5,408,242 $5,373,492 $4,916,404
2025 150,000 $11,043,430 $11,006,333 $9,254,262
2030 150,000 $15,511,885 $15,470,097 $12,647,120
2035 150,000 $18,697,831 $18,652,700 $15,066,182
Comparison of present value at 7% interest of aerobic, anaerobic, and no
pretreatment options
Water quality criteria for design of pretreatment process (ppm)
Introduction Financial Analysis
Water Quality Criteria
Process Flow Diagram
Tank Design
● Grain particle density determined experimentally using Stokes equation
○ vc
= gD2
( p
- f
)/(18* )
● Scouring velocity of grain particles and inorganics determined using
Shield’s equation
○ vscour
= (8 ( p
-1)Dp
/f)½
● Scouring velocity used to determine grit chamber sizing and flow rate
● Equalization tank designed using model of variable flow rate shown below
○ VEQ
= 3700 ft3
Decision matrix used to quantify the degree to which each option satisfies criteria. Weighted
values based upon percieved importance to overall design.