© 2015 HDR, Inc., all rights reserved.

Hastings Utilities Water Pollution Control Facility ImprovementsBrian Bakke , HDR

ASCE Environmental Conference

4/6/2017

Review Existing Facilities

Need for the Project

Study Phase

Design Phase

Construction Phase

Start-Up and Operation

01 Review Existing Facilities

Existing Facility Site Plan

Rotating Biological Contactors (not in operation)

Trickling Filter provides bulk of treatment

Existing Facility

02 Need for the project –Permit Limits

Existing permit (effective July 1, 2008) includes transition to final lower

ammonia limits

Permit Compliance Dates

January 31, 2012 – Submit Design for Upgrades

June 30, 2012 – Initiate Construction

April 2014 – Be in Compliance

Permit Limits - Ammonia

Condition 2003 Permit

2008 Permit

Interim

2008 Permit

Final

Fall and Winter Ave. 8.1 mg/l 8.7 mg/L 2.48 mg/L

Spring and Summer Ave. 8.5 mg/l 8.1 mg/L 1.88 mg/L

Residential growth projected at

0.5% per year. Same as Water

Master Plan

Study: Future Flows and Loadings

Year Population

2010 25,226

2015 25,862

2020 26,516

2025 27,185

2030 27,872

Prior to June 2009 Influent to PCF - 50-65% industrial wastewater

Since July 2009 two major industries have not been in operation.

New tenants plan on resuming operation in the near future.

Discussions with each industry helped establish projected flows and

loads when they resume operation. (60% of previous contributions)

Industrial reserve of built into planning numbers to account for potential

future industries.

Industrial Contributions

Projected Flows

Projected CBOD Loadings

Biochemical

Oxygen Demand

(BOD) removed

before ammonia

is removed.

High BOD load

does not leave

enough room for

ammonia removal

zone.

Existing Facility: Trickling Filter

BOD Removal

Zone

Ammonia

Removal Zone

Inflow

Outflow

Existing plant has capacity to meet interim permit with trickling filter

through 2015 with some reserve for industry

Existing plant does not have capacity to meet final permit limits, even at

current loadings.

Additional facilities are needed to achieve the new limits.

Existing Treatment Facility

What should be built and how much??

What other regulatory drivers should be considered??

Future Permit Limits

Future Permit Scenarios Considered:

• 10 mg/L TN and 1.0 mg/L TP (7-12 years)

• 5 mg/L TN and 0.5 mg/L TP (15-20 years)

• 3 mg/L TN and 0.3 mg/L TP (>20 years)

Recommended Improvements: Evaluation Methodology

Regulatory Timeline

Current

Limits

Lower Ammonia

Limits

10 mg/L TN

1 mg/L TP

5 mg/L TN

0.5 mg/L TP3 mg/L TN

0.3 mg/L TP

Long Term

Improvements

Short Term

Three options evaluated for existing final ammonia permit limits

Activated sludge lowest cost option

All options utilized the existing Trickling filter in a parallel mode

operation

Improvements to Meet Existing Ammonia Limits

Cost Component

Alternative 1 –

Activated Sludge

Alternative 2 -

IFAS

Alternative 3 -

MBBR

Estimated Capital Costs $8,680,000 $8,050,000 $10,250,000

Estimated Present Worth

O&M Costs$1,880,000 $2,890,000 $3,930,000

Total Present Worth Life

Cycle Costs$10,560,000 $10,940,000 $14,180,000

Proposed Site Plan for Recommended Improvements

03 Study Phase

Study Methodology

Regulatory Timeline

Current

Limits

Lower Ammonia

Limits

10 mg/L TN

1 mg/L TP

5 mg/L TN

0.5 mg/L TP3 mg/L TN

0.3 mg/L TP

Long Term

Improvements

Short Term

Evaluation of Future Limits(10 mg/l N and 1 mg/l P)

Cost Component

Alternative 1 –

Trickling Filters

with Activated

Sludge

Alternative 2 –

BNR Activated

Sludge

Alternative 3 –

Hybrid Process

Number of Trickling Filters in

ServiceTwo Zero One

Estimated Capital Costs $16,430,000 $12,300,000 $10,420,000

Estimated Present Worth

O&M Costs$5,341,000 $2,827,000 $2,678,000

Total Present Worth Life

Cycle Costs$21,771,000 $15,127,000 $13,098,000

Plan developed for future more restrictive permits

Implementation Plan

Chosen Path Forward by the City

$10,420,000

Permit Limit

Existing Final

Ammonia

10 mg/L

Nitrogen

1 mg/L

Phosphorous

5 mg/L

Nitrogen

0.5 mg/L

Phosphorous

3 mg/L

Nitrogen

0.3 mg/L

Phosphorous

Estimated Timing Now 7-12 years 15-20 years >20 years

Estimated Capital Cost $8,680,000 $1,740,000 $2,500,000Increase in

Operational Cost

04 Design Phase

Design Criteria

Peak WW flow – 15 MGD

2030 Avg Annual Max Month Peak Day

Flow MGD 5.3 5.7 7.0

CBOD lbs/day 10,300 17,800 29,600

mg/l 234 377 508

TSS lbs/day 8,600 14,600 26,300

mg/l 195 309 450

NH3 lbs/day 930 1,370 4,470

mg/L 21 29 77

Design – Site Layout

Enhanced Nitrification BNR Activated Sludge - ENBNRAS

ScreenGrit Removal

Primary

Clarifiers

Lagoon

Storage

Land

Application

Secondary

Digestion

Primary

Digestion

Influent

Final EffluentAnoxic

A

BA

B

B

Anaerobic Aerobic

Secondary

Clarifiers

(14-FT SWD)

RAS

MLR

WAS

Nitrification Only

Nitrogen Removal

Full BNR Mode

Design – BNR Basin

Aeration

Basin

Effluent

Aerobic Anoxic Anaerobic

`Anoxic Anaerobic

Anoxic

Anoxic CS No. 8

PE Splitter

Aerobic

Design – BNR Basin

Aeration

Basin

Effluent

Aerobic Anoxic Anaerobic

`

To Inter.

Clar.

Anoxic Anaerobic

Anoxic

Anoxic CS No. 8

PE Splitter

MLR

MLR

MLR

MLR

Aerobic

Design – BNR Basin

Aeration

Basin

Effluent

Aerobic Anoxic Anaerobic

`

To Inter.

Clar.

Anoxic Anaerobic

Anoxic

Anoxic

CS No. 9 RAS SplitterCS No. 10 Trickling

Filter Effluent Splitter

CS No. 8

PE Splitter

MLR

MLR

MLR

MLR

Aerobic

Anaerobic, Anoxic and Aerobic zones

• 194’ length x 46’ width x 22’ tall concrete

tank

Fine Bubble Diffusers

• 9” Membrane Discs

Submersible Mixers (3 per train) – 10 HP

Mixed Liquor Recycle Pumps (2 per train)

• Anoxic to Anaerobic – 2,000 GPM, 10 HP

• Aerobic to Anoxic – 4,900 GPM, 40 HP

Design – BNR Basin

Design – BNR basin

4 RAS pumps – VTSH type

• 2,500 GPM, 40 HP

2 WAS Pumps – Self

Priming

• 250 GPM, 7.5 HP

2 ILS Pumps – VTSH Type

• 5,600 GPM, 40 HP

Design – Pump/Blower Building

4 High Speed Turbo Blowers

• 2,500 SCFM, 150 HP

• VFD

Stand by Generator

Electrical and Control Room

Design – Pump/Blower Building

Final Clarifier

• 80’ Diameter

• Stainless Steel

Mechanism

Design – Final Clarifier

Design – Site Layout

Lift

Station

Final

Clarifier

Aeration

Basin

Bid in April 2012

Four Bids

Project awarded to Eriksen Construction, Blair, NE

Engineers Estimate - $11.5 million

Design – Bid Results

Eriksen

Construction

John T Jones

Construction

PKG

Contracting

BRB

Contractors

$10,431,000 $10,970,000 $11,096,000 $11,782,000

05 Construction Phase

Contract Price:

Construction Timeline

June 2012

Eriksen issued

Notice to Proceed

2012 2013 2014

January 15, 2014

Substantial Completion

March 15, 2014

Final Completion

Mid-Late November

Startup activities begin

Contractual Dates

85-90% Complete

Bid:

$10,413,000

Final:

$10,487,000

Change Orders:

0.7%

Aeration Basin

Electrical Room MCC

Pump Room

Pipe Gallery – Dry well area

West Exterior View

Final Clarifier

06 Start-Up and Operation

Parallel Flow Process

Will be used at

startup

Allows staff to

become familiar

with AS

Operational cost

savings

Influent Loadings

Effluent Quality

Effluent Quality

Nitrogen Removal Performance

Effluent Phosphorus

Questions