AEP Water/Wastewater SeminarDelphos, Ohio

May 25, 2016

Michael Atherine, P.E.

Senior Managing Principal

I. Original Wastewater System Overview

II. Problems / Issues Encountered

III. Evaluation Process

IV. Selected Replacement Process

V. Comparison – Original vs. Replacement

Wastewater Treatment Overview

Original WWTP

Original WWTP

• Membrane Bioreactor Technology

• Constructed 2005/2006

• Construction Cost - $32 Million

• Average Day Design Capacity – 3.83 MGD

• Peak Day Capacity – 12.0 MGD

• Design Population Equivalent – 70,000

• Number of Bioreactor Trains – 5

• Flat Plate Membrane Plates Per Train – 10,400

• Total Number of Flat Plate Membranes – 52,000

• Largest Flat Plate Membrane Bioreactor Facility in the World at Time of Construction

Original MBR Trains

Original MBR Schematic

Membrane Cassettes

Membrane Unit

Membrane Plate

Membrane Blowers

Wastewater Treatment Plant Issues

• Fouled-Failed Membranes/Reduced Plant Capacity

• Blower Failures/Common Air Header

• Blower Turn-Down Flexibility

• High Electric Power Consumption Associated with Membrane Bioreactor Process ($400,000 Annually)

• Influent Raw Sewage Screening

• Hydraulic Flow

• Peak Wet Weather Flow

Fouled Membrane Cassette

Fouled Membrane

Membrane Replacement Evaluation Process

• Replacing with same membrane ruled out due to both high membrane cost ($6,000,000+/-) and high annual power cost ($400,000)

• Evaluated ten (10) different membrane types including flat plate, hollow fiber and a combination of flat plate and hollow fiber.

• Also evaluated converting to a non-membrane conventional-type wastewater treatment process.

• Membrane replacement evaluation team consisted of two (2) City Administrative Staff, four (4) City Plant Operational Staff and PDG.

• Presentations given by manufacturers of the eleven (11) replacement options to evaluation team.

Membrane Replacement Evaluation Process

• Short-listed four (4) membrane manufacturers/types• Two (2) manufacturers of hollow fiber membranes

• Flat plate membrane

• Hybrid hollow fiber/Flat plate membrane (new on market)

• Detailed presentation including cost from each short-listed manufacturer/membrane type

• Evaluation also included non-monetary criteria:

• Equipment reliability• Fouling potential• Experience• Manufacturer’s team• References contacted

• Operability• Handling peak flows• Cleaning requirements• Owner preference

Non-Monetary Evaluation CriteriaType of Impact Weight Value Impact Vale Total

1. Equipment Reliability 5

a. Ease of Replacementb. Cleaning Frequencyc. Fouling Potentiald. Warranty

2. Experience 3

a. No. of Larger Installationsb. Manufacturer’s Teamc. No. of Years in Service

3. References 3

a. Contactsb. List of Plants in Operations

4. Operability 5

a. Handle Peak Wet Weather Flowb. Automated Cleaningc. No. of Membranes

5. Owner Preference 5

Weight Value1 – Minimal Importance3 – Important5 – Very Important

Impact Value1 – Minimal Rating or Beneficial Impact3 – Average Rating or Beneficial Impact5 – Significant Rating or Beneficial Impact

Cost Comparison Summary

Membrane Replacement Type

Hybrid Hollow Fiber/Flat Plate

Hollow FiberType 1

Hollow FiberType 2

Flat Plate

No. of Membrane Trains 4 4 3 3

Equipment Cost $2,687,000 $2,828,000 $3,025,000 $4,740,000

Blower Annual Power Cost $80,000 $85,000 $102,000 $236,000

Note: Existing Annual Power Cost: $400,000 +/-

Non-Monetary Evaluation Summary

Membrane Replacement Type

EvaluatorHybrid Hollow Fiber/Flat Plate

Hollow FiberType 1

Hollow FiberType 2

Flat Plate

City 1 114 120 88 37

City 2 116 104 78 57

City 3 105 99 81 36

City 4 83 96 81 33

City 5 107 102 81 44

City 6 111 98 76 31

PDG 94 92 68 34

Selected Membrane Replacement

• Based on both monetary and non-monetary criteria, the hybrid hollow fiber / flat plate membrane as manufactured by Fibracast, was the selected membrane replacement process.

Membrane Replacement Process

Fibracast Membrane Cassette

Fibracast Membrane Demo Train

Full Build-Out Schematic

Membrane Replacement Process

Comparison – Original vs. Replacement

ItemExisting Membrane

SystemReplacement Membrane

System

Membrane Trains 5 3

Membrane Cassettes 130 12

Membrane Units 52,000 16,128

Actual Monthly Avg. Power Usage (kWh) 531,600* 237,400**

* Based on 2015 power usage at 0.8 to 1.0 MGD** Based on February, March & April 2016 Replacement System at 1.2 MGD