Seaside WWTP and Pump Station Assessment_Final 070924.pdf

City of Seaside

Wastewater Treatment Plant and Pump Stations

Condition Assessment Report

May 2024

Prepared by

City of Seaside Wastewater Treatment Plant and Pump Stations Condition Assessment – May 2024

Table of Contents

1. Introduction

1.1 Purpose

1.2 Organization

1.3. System Description

1.4 System Summary

2. Condition Assessment Approach

2.1 Condition Assessment Techniques

2.2 Condition Assessment Rating

3. System Condition Assessments

3.3.1 Headworks

Condition Rating Table 3.3.1

3.3.2 Equalization Basins

Condition Rating Table 3.3.2

3.3.3 Oxidation Ditches

Condition Rating Table 3.3.3

3.3.4 Secondary Clarifiers

Condition Rating Table 3.3.4

3.3.5 RAS WAS Pump Station

Condition Rating Table3.3.5

3.3.6 Chlorine Contact Basins

Condition Rating Table 3.3.6

3.3.7 Ultraviolet (UV) Disinfection System

Condition Rating Table 3.3.7

3.3.8 Gravity Thickeners

Condition Rating Table 3.3.8

3.3.9 Aerobic Digesters

Condition Rating Table 3.3.9

3.3.10 Sludge Dewatering

Condition Rating Table 3.3.10

3.3.11 Sludge Drying

Condition Rating Table 3.3.11

3.3.12 Administration Building

Condition Rating Table 3.3.12

3.3.13 Support Systems

Condition Rating Table 3.3.13

3.3.14 Sewage Lift Station System

Pump Station Condition Table 3.3.14

Lift Station #1

Lift Station #2

Lift Station #3

Lift Station #4

Lift Station #5

Lift Station #6

Lift Station #7

Lift Station #8

Lift Station #9

Lift Station #10

Lift Station #11

Lift Station #12

Lift Station #13

Lift Station #14

Lift Station #15

Lift Station #16

Lift Station #17

Lift Station #18

Lift Station #19

Lift Station #20

Lift Station #21

Lift Station #22

Lift Station #23

Lift Station #24

Lift Station #25

5. Results

1. Introduction

This assessment report is intended to inform decision making for current facility planning efforts. System condition information can also be used to prioritize future repair and refurbishment projects.

The City of Seaside (City) owns and operates a Wastewater Treatment Plant (WWTP) designed for an average flow of 2.25 million gallons per day (MGD) with a maximum capacity of 6.75 (MGD). The original facility was constructed in 1939 and memorialized with a plaque posted on the administrative building (cover).

Subsequent improvement projects were completed in 1962, 1984, 2001 and (dryer project date). Most of the operating equipment and structures were installed as part of the 1984 improvements project.

Over the past twenty years an ultraviolet disinfection system and dewatering system have been added.

A new headworks screen and compactor were installed in 2018.

Condition assessment activities began in March 2024. Activities included staff interviews, facility inspection, and review of various facility documents. Operation, maintenance, and repair work is performed by city staff. Specialty craft work including SCADA, instrumentation, electrical, and equipment rebuilds is performed through contracted services.

Asset conditions are based on conditions observed March 19-21, 2024. Several replacement projects were underway at the time of the assessment. These projects were considered in the development of system ratings if completed by April 1, 2024.

Systems and components are rated using the rating scale described in Table 1.0. This rating system is published by the Association of Metropolitan Sewerage Agencies (AMSA) in Managing Public Infrastructure Assets to Minimize Cost and Maximize Performance, 2002.

Table 1.0

SCORE CONDITION DESCRIPTION

0 Abandoned Asset Abandoned, not longer in use, or no longer exists

1 Very Good Sound physical condition. Meets current needs. Operative and well maintained. Asset expected to perform adequately with routine maintenance for 10 yr. or more. No work required.

2 Good Acceptable physical condition. Shows minor wear that has minimal impact on performance. Minimal short term failure risk. Potential for deterioration or impaired performance over next 5-10 years. Minor work (if any ) required.

3 Fair Functionally sound but showing wear and diminished performance. Moderate short term failure risk.

Potential for further deterioration and diminished performance within next 5 years. Renewal or major component replacement expected within next 5 years. Minor work required but asset is serviceable.

4 Poor Asset functions but required high level of maintenance to remain operable. High risk of short term failure. Likely to have significant deterioration in performance within next two years. Renewal or replacement expected within next 2 years. Substantial work required, asset barely serviceable.

5 Very Poor Asset failed or failure is imminent. Excessive maintenance required. No further service life expectancy.

Significant health and safety hazard. Major work or replacement is urgent.

Source: Association of Metropolitan Sewerage Authorities, "Managing Public Infrastructure Assets" 2002

The overall average condition rating for the WWTP is Fair to Poor based on Table 1.2. The condition ratings for the Sewage Lift Stations range from Good to VeryPoor as shown on Table 1.3.

Table 1.2 Table 1.3

Overall Condition Rating

(1 = Very Good, 5 = Very Poor)

Lift Station #1 3.2

Lift Station #2 3.0

Lift Station #3 5.0

Lift Station #4 3.0

Lift Station #5 2.5

Lift Station #6 3.0

Lift Station #7 3.5

Lift Station #8 4.0

Lift Station #9 4.0

Lift Station #10 2.5

Lift Station #11 3.0

Lift Station #12 3.5

Lift Station #13 4.5

Lift Station #14 3.0

Lift Station #15 3.0

Lift Station #16 3.5

Lift Station #17 3.0

Lift Station #18 3.5

Lift Station #19 4.0

Lift Station #20 3.5

Lift Station #21 3.0

Lift Station #22 2.5

Lift Station #23 2.5

Lift Station #24 2.5

Lift Station #25 2.0

Overall Average 3.2

City of Seaside Wastewater Sewage Lift Stations

System Identification

(1 = Very Good, 5 = Very Poor)

Headworks 3.7

EQ Basins 3.3

Oxidation Ditches 3.7

Secondary Clarifiers 3.4

RAS WAS Pump Station 3.6

Chlorine Contact Basins 3.0

UV Disinfection 3.5

Gravity Thickeners 3.8

Aerobic Digesters 3.1

Sludge Dewatering 2.7

Sludge Drying 2.7

Administration Building 2.5

Support Systems 3.7

Overall Average 3.3

City of Seaside Wastewater Treatment Plant

Detailed information regarding system conditions is included in Section 4 System Condition Assessments. The systems and individual components at most risk of failure (rating 4 or 5) is identified in Section 5 Results.

The next step in evaluating and prioritizing the information in this report is to conduct a system risk and criticality assessment. A system risk and criticality assessment will be scheduled upon completion of this assessment report. The results of the system risk and criticality assessment will aid the City with prioritizing actions for systems most at risk of failure.

1.1 Purpose

The purpose of this report is to provide the City of Seaside with an assessment of the condition of assets at the Wastewater Treatment Plant (WWTP) and sewage lift stations. The information in this report is intended to be used to develop strategies for system replacement, repair, or refurbishment.

1.2 Organization

In addition to the Executive Summary and this introductory section, this report includes the following sections:

Section 2. System Description.

Introduces the WWTP system table and summarizes the assets in each system.

Section 3. Condition Assessment Approach.

Describes the approach used to determine the asset condition and the rating table used to apply a score to each condition status.

Section 4. System Condition Assessments.

Each individual WWTP system assessment is organized to include the following:

• System Condition Summary. Provides a brief overall summary including information on the operational performance of the system.

• Component Condition Summary. Provides a component level narrative condition description based on the condition rating.

• Condition Ratings Table. Includes the component condition score and provides a rating for the overall condition of the system. Each asset was assigned an Asset Condition Rating based on the scale shown in Table ES1.

• System Photo Summary. Includes system specific photos referenced in the condition ratings table.

The sewage lift station conditions and ratings are presented as Pump Station Condition Table

3.3.14. A summary page for each pump station follows and includes a photo summary and pump runtime analysis during the period January 1 to February 28, 2024.

Section 5. Results.

Provides the overall ratings for the WWTP and lift stations. A table follows that lists the components within each system that rated poor to very poor. These are considered the components that are at the greatest risk of failure.

1.3. System Description

The following condition report is formatted around functional systems described below. Systems were derived from the Process and Instrumentation Diagrams found in the City of Seaside, Wastewater Treatment Plant Expansion and Upgrade drawings.

Currently there is not a standard for describing or numbering assets. Asset descriptions and numbering conventions are important when developing a maintenance management system. Consistent tagging of equipment between SCADA, local at the equipment and at MCC help ensure effective energy control measures. Developing a consistent naming and numbering convention ensures the same schemes are found on the field tags for the associated assets. This report is being delivered with an Excel spread sheet that includes all assets evaluated for this project. The sheet entitled "Seaside Systems V0” is intended to support development of a maintenance management system.

System identification is derived from the City of Seaside, Wastewater Treatment Plant Expansion drawings. The intent of this strategy is to maintain existing nomenclature so that the information in this report can be used to support future asset maintenance management efforts. Table 2 provides a summary of the systems included in this report.

Table 2.

City of Seaside Wastewater Treatment Plant

System

Headworks

EQ Basins

Oxidation Ditches

Secondary Clarifiers

RAS WAS Pump Station

Chlorine Contact Basins

UV Disinfection

Gravity Thickeners

Aerobic Digesters

Sludge Dewatering

Sludge Drying

Administration Building

Support Systems

Sewage Lift Stations

1.4 System Summary

The following system summary provides a brief description of the assets in each of the systems.

Headworks

The headworks consists of a two-level concrete structure. The lower area houses the motor controls, influent flow meter, grit pumps and associated piping. The upper area houses a manual bar screen, mechanical screen, influent sampler, washer compactor, grit removal turbines and grit separator.

Equalization Basins

The equalization basins consist of two basins, each with a floating aerator and a pump station. The basins receive overflow from the headworks and flow from the thickener effluent wet well. The thickener wet well pumps scum from the chlorine contact basins. There is an emergency overflow on EQ basin 2 that flows to the chlorine contact basins. The equalization return flow pump station pumps flow to the degritting system.

Oxidation Ditches

The oxidation ditches include two 1.1 million gallon concrete basins. Each basin includes a flow meter, flow control valve, two motorized disc aerators, and an effluent water control gate.

Secondary Clarifiers

Includes two 60-ft diameter secondary clarifiers with peripheral weirs, launders, a motorized drive unit, and a suction duct sludge removal system.

RAS WAS Pump Station

The RAS WAS Pump Station includes a concrete structure, three return activated sludge (RAS) pumps and three waste activated sludge (WAS) pumps, valves, and piping.

Chlorine Contact Basins

Chlorine is no longer used for disinfection. The two basins now provide tertiary settling and final scum removal prior to ultraviolet disinfection.

Ultraviolet (UV) Disinfection

The UV system consists of a concrete structure, wooden building, a Trojan UV 4000 system, flow meters, pH, and transmittance sensors.

Gravity Thickeners

The two gravity thickener units are used for thickening solids. The units are not in the normal flow stream and used as needed to thicken solids. The thickener effluent pump station is used to pump scum from the chlorine contact basins.

Aerobic Digesters

A single concrete structure includes aerobic digesters each with turbine mixers and blowers. A sludge transfer pump room is located at the ground level.

Sludge Dewatering

Sludge is dewatered using a belt filter press. The system includes sludge pumps and polymer dosing.

Sludge Drying

Dewatered sludge is fed to a Fenton Dryer. The dryer system uses high temperature oil to dry the sludge.

Administration Building

The administration building includes an office area, laboratory, storge and a mechanical room.

Support Systems

Support systems include plant W3 water, standby power, and perimeter fencing.

Sewage Lift Stations

The sewage lift stations consist of 25 separate pumping stations located throughout the collection system. The stations include sewage lift, submersible and wet pit/dry pit designs. Most of the pump configurations are duplex with one triplex pump.

2. Condition Assessment Approach

This section explains the approach used for the condition assessment and provides details on how the ratings are derived.

2.1 Condition Assessment Techniques

The condition assessments are based on a review of available information, staff knowledge, and physical inspection of facilities. Mechanical and control system condition assessment activities included visual inspection, interviews with staff, and observation of operation when possible. Electrical distribution system evaluation is not included in this assessment.

The systems are rated on asset condition and operational performance. The condition assessment process included development of an asset and systems register. Operations staff were interviewed to obtain historical operation and maintenance history. A review of asset work history was not performed because the facility does not maintain a computerized maintenance management system.

Two handheld field instruments were used to evaluate mechanical equipment condition during operation.

These devices are used to detect and document conditions that require further investigation.

• FLUKE Model 805 FC Vibration Meter is used to assess bearing condition and vibration.

• FLIR Ex-Series Infrared Camera is used to assess equipment for friction anomalies, overheating conditions, and heat patterns.

2.2 Condition Assessment Rating

The system condition rating is determined by averaging the component ratings within a system. The final system condition rating is determined after considering operational impact and reliability concerns.

Asset condition ratings are scored based on the definitions in table 3.0.

Table 3.0

SCORE CONDITION DESCRIPTION

0 Abandoned Asset Abandoned, not longer in use, or no longer exists

1 Very Good Sound physical condition. Meets current needs. Operative and well maintained. Asset expected to perform adequately with routine maintenance for 10 yr. or more. No work required.

2 Good Acceptable physical condition. Shows minor wear that has minimal impact on performance. Minimal short term failure risk. Potential for deterioration or impaired performance over next 5-10 years. Minor work (if any ) required.

3 Fair Functionally sound but showing wear and diminished performance. Moderate short term failure risk.

Potential for further deterioration and diminished performance within next 5 years. Renewal or major component replacement expected within next 5 years. Minor work required but asset is serviceable.

4 Poor Asset functions but required high level of maintenance to remain operable. High risk of short term failure. Likely to have significant deterioration in performance within next two years. Renewal or replacement expected within next 2 years. Substantial work required, asset barely serviceable.

5 Very Poor Asset failed or failure is imminent. Excessive maintenance required. No further service life expectancy.

Significant health and safety hazard. Major work or replacement is urgent.

3. System Condition Assessments This section includes individual system condition assessments.

The electronic version of this report allows the reader to access each individual system assessment by clicking the link to each system from the links below or from the Table of Contents for this report.

Table 3.0

Headworks

LS#1 LS#14

Equalization Basins

LS#2 LS#15

Oxidation Ditches

LS#3 LS#16

Secondary Clarifiers

LS#4 LS#17

RAS WAS Pump Station

LS#5 LS#18

Chlorine Contact Basins

LS#6 LS#19

Ultraviolet Light (UV) Disinfection System

LS#7 LS#20

Gravity Thickeners

LS#8 LS#21

LS#9 LS#22

Sludge Dewatering

LS#10 LS#23

Sludge Drying

LS#11 LS#24

Administration Building

LS#12 LS#25

LS#13 Pump Station Condition Summary

3.3.1 Headworks

The Headworks system consists of the following components:

• Mechanical Screen and Compactor

• Flow monitoring.

• Grit Removal

• Valves, Gates & Piping

• Influent Sampler

System Condition Summary

The headworks receives flow from pump station #3 and #18. The headworks includes a provision for peak flow diversion to equalization basins. Flow volume is managed by manipulating a manual weir.

The headworks system is in fair to poor condition. With the exception of the mechanical screen and compactor, the system has been in operation since 1984. The equipment supporting this system is in working condition.

Corrosion of major components is the cause of the poor condition ratings. Optimization of the grit removal is not possible due to failed torque indicators and pressure gauges.

Component Condition Summary

Mechanical Screen and Compactor

The screening and compactor system is in fair condition. The screen cover is off posing a safety hazard. The compactor wash water controls are exposed to weather and show moderate corrosion.

Flow monitoring

The magnetic flow meter is in fair condition and was calibrated within the past 6 months. The measurement range for the 14” flow meter is 0-5,000 gallons per minute.

Grit Removal

The grit removal system is in fair to poor condition due to corrosion of grit basin components. The hydro cyclones and grit separator are in fair condition. Pressure gauges for hydro cyclones are not operable preventing adjustment. Torgue gauges for the grit detritor are not operable, operators cannot see the grit load on the mechanism.

Valves, Gates & Piping

Piping and valves are in fair condition. The water control gates are in Poor condition due to delamination of the frames.

Influent Sampler

The influent sampler is in working condition and rated as very poor. The sampler does not meet the sample quality requirements for refrigeration on the composite sample.

Condition Rating Table 3.3.1

System

Asset Description Condition

Rating Condition/Performance Comments Photo Reference

Mechanical Screen and Washer Compactor 3

Stainless steel components fair. Weather exposed electrical connection corrosion of screenings washer components. Screenings cover off. Level indicator wiring exposed.

3.3.1 F,G,H,I

Grit Detritor 1 5 Severe drive unit corrosion and delamination. No adjustment due to torque gauge not readable.

Grit Detritor 2 5 Severe drive unit corrosion and delamination. No adjustment due to torque gauge not readable.

Hydro Cyclone 1 4 Thermography normal. Moderate surface corrosion.

Corrosion and flanged connections. Pressure gauge not operable.

Hydro Cyclone 2 4 Thermography normal. Moderate surface corrosion.

Corrosion and flanged connections. Pressure gauge not operable.

Grit Classifier 3 Water Leak at lower bearing. Drive and motor overhang difficult to access for maintenance.

3.3.1 O,P

Grit Pump 1 4 Thermography normal. Vibration elevated indicating bearing wear. Moderate corrosion.

3.3.1 A,B,C

Grit Pump 2 4 Vibration elevated indicating bearing wear. Moderate corrosion. Concrete pump base failing. PVC pipe suction piping repair.

3.3.1 D,E

Plant Influent Flow 3 14" Sparling FS650 Magnetic Flow Meter Calibrated 1/18/24

3.3.1 U

Piping 3 Pipe flanges showing moderate corrosion. n/a

Gates 4 Slide gate frames severer corrosion and delamination. 3.3.1 S,T

Valves 3 Appear in fair condition; Knife Gate at inf flow meter 3.3.1 U

2" Backflow Assembly Not inspected. n/a

Influent Sampler Sampler has no refrigeration. Replacement urgent. 3.3.1 T

Controls 4 Corroded gutter, temporary repairs in place. 3.3.1 V

Condition Rating 3.8

Headworks

Condition = 1 Very Good, 2 Good, 3 Fair, 4 Poor, 5 Very Poor

3.3.1 N,Q,R

3.3.1 J,K,L,M

System Photo Summary

Headworks structure

Figure 3.3.1 A

Figure 3.3.1 B

Figure 3.3.1D

Figure 3.3.1C

Figure 3.3.1 E

Figure 3.3.1 F Figure 3.3.1 G

Figure 3.3.1 H Figure 3.3.1 I

Figure 3.3.1 J

Figure 3.3.1 K

Figure 3.3.1 L

Figure 3.3.1 M

Figure 3.3.1 N

Figure 3.3.1 O

Figure 3.3.1 P

Figure 3.3.1 R

Figure 3.3.1 Q

Figure 3.3.1 S

Figure 3.3.1 T

Figure 3.3.1 U

Figure 3.3.1 V

3.3.2 Equalization Basins

The Equalization Basin System consists of the following components:

• Equalization Basins

• Floating Aerators

• Equalization Pumps

• Flow monitoring

• Valves

System Condition Summary

The equalization basin system is used to equalize flow to the oxidation diches. There are two 0.8-million-gallon capacity equalization basins, each with a mechanical floating aerator to provide mixing. A pumping system is located in between the two basins to facilitate return flow to the headworks.

The equalization basin system is in fair condition.

Component Condition Summary

Equalization Basins

Equalization basins appear in fair condition. There the trees growing in the dike should be evaluated for impact to dike structure. A complete walk of the basin dike showed one rodent hole. Some areas may need additional rip rap due to settlement.

Floating Aerators

The floating aerators are in fair condition. Both mixers are operational and present good mixing energy when in operation.

Equalization Pumps

The submersible pumps are reported to be in fair condition.

Valves

Corrosion

Condition Rating Table 3.3.2

Photo Summary

Condition

Rating Condition/Performance Comments Photo Reference

Equalization Basin 1 3 3.3.2 A, C

Equalization Basin 2 3

Floating Aerator 1 3 Floating Aerator 2 3 Equalization Pump 1 3 Equalization Pump 2 3 Equalization Pump 3 3 Flow Monitoring 4 3.3.2 B

Overflow Structure 4 Overflow detector broken, temporary structure over the overflow is in poor condition.

3.3.2 E, F

Valves 5 Check valve leakage, Plug Valve handle broken. Valve handle corrosion.

3.3.2 D

Condition Rating 3.4

Equalization Basins

Condition = 1 Very Good, 2 Good, 3 Fair, 4 Poor, 5 Very Poor

Clay lined with rip rap dike. A complete walk of the basin dike showed one rodent hole. Trees are going in the dike. Rip rap closest to Admin bldg. low, lacks rock.

Operating. Anchor post guide cables in place.

Pumps operable. Submersible pump guides, lifting bracket good condition.

3.3.2 G

3.3.2 F

Figure 3.3.2 A

Figure 3.3.2 C

Figure 3.3.2 B

Figure 3.3.2 D

Figure 3.3.2 E

Figure 3.3.2 G

Figure 3.3.2 F

3.3.3 Oxidation Ditches

The Aeration Basin system consists of the following components:

• Oxidation Ditches

• Surface Aerators

• Flow Meter

• Effluent Weir Gate

• Flow Control Valve

• Handrails

• Piping

System Condition Summary

The oxidation ditch system is in poor condition. This rating is developed from a combination of poor physical asset condition and lack of operational control. The purpose of this system is to provide secondary treatment to incoming wastewater. Lack of reliability and control of this system represents a potential for NPDES permit exceedance.

The oxidation ditch system is designed with two basins. Each basin has two (2) disc mixer aerator units installed to provide aeration and mixing. The aerators show significant vibration during operation. A 2007 CH2MHill assessment identified vibration and stress being caused by the not being able to adjust water level due to the failure of the effluent weir gates and the configuration aerator motor mounts.

The failed effluent weir gates prevent aeration adjustment. The design of this system is to adjust aeration by increasing or decreasing the submergence of the aerator discs. This severely limits the operator’s ability to adjust to changing air demands. Speed is currently the only aeration control point.

The operation of the oxidation ditch aeration system is not automated. Manual adjustment is required to adjust to any changes to operating conditions. The system also lacks continuous dissolved oxygen monitoring for each basin. Operators currently must perform manual measurement during the day. This practice does not provide information on the system biological condition when staff are off site or performing other tasks.

Some of the entrance points to the bearing shaft assemblies are lacking safety chains to prevent incidental exposure to rotating shafts.

Component Condition Summary

The concrete basins are above ground and appear in good condition. Minimal exposed aggregate and water leakage, or surface cracking were observed.

Surface Aerators

There are four matching surface aerators. The aerator discs appear in Fair condition. When the aerators are in operation they exhibit significant vibration. Stress from this condition has caused premature failure of gearboxes, bearings, and motor mounts. Shaft bearings are in Fair to good condition due to being replaced frequently. Shafts and splash guards show moderate to severe corrosion.

Motor conditions range from new to poor. Thermography of the motors, gearboxes and shafts were all with in normal ranges.

Flow Meter

The magnetic flow meters have been in operation for over 25 years. During this time, one of the displays has been replaced and one meter has been repaired. Coatings and connections are good. Flanged connections indicate internal corrosion.

Effluent Weir Gate

The effluent weir gate for both ditches has failed in the low position. This prevents adjustment to the amount of applied oxygen to the oxidation ditch. The gate is submerged. The exposed gate stem. Stem guides, and motor actuator are corroded beyond repair.

Flow Control Valve

Flow control valves are in place and operational.

Handrails

The galvanized steel handrails appear in Fair condition. Near complete corrosion of the basin 2 handrail posts create an overall poor condition.

Piping

The oxidation diches receive influent and effluent flow via large diameter steel pipe. The exterior of most pipes is coated. Signs of internal corrosion are indicated by corrosion at the pipe connections.

Condition Rating Table 3.3.3

Condition

Rating Condition/Performance Comments Photo Reference

Oxidation Ditch #1 3 Concrete basins show few signs of exposed aggregate, or leakage.

3.3.3 A & B

Oxidation Ditch #2 3 Concrete basins show few signs of exposed aggregate, or leakage. Concrete stair/walkway shows cracks

3.3.3 A, B, C

Surface Aerator #1A 4 New motor and gearbox. Severe shaft corrosion.

Bearing thermography normal. Discs Fair, Splash guards corroded. n/a

Surface Aerator #1B 5 Motor has internal short. Gearbox leakage. Moderate vibration. Discs Fair. Severe shaft corrosion. Bearing thermography normal range. Splash guards corroded.

3.3.3 F

Surface Aerator #2A 4 Motor good. Gearbox leakage. Moderate vibration.

Discs Fair. Severe shaft corrosion. Bearing thermography normal range. Splash guards corroded.

3.3.3 A

Surface Aerator #2B 4 Motor cover cracked. Moderate vibration. Disc Fair.

Severe shaft corrosion. Bearing thermography normal range. Splash guards corroded.

3.3.3 G

Flow Meter AB 1 3 Sparling FS622 12" magnetic flow meter moderate corrosion. Siemens display working. Calibrated Jan 2024. n/a

Flow Meter AB 2 3 Sparling FS622 12" magnetic flow meter moderate corrosion. Sparling Tiger Mag display working. No Calibration sticker. 3.3.3 I, M

Effluent Weir Gate #1 5 Inoperable due to severe corrosion. 3.3.3 J Effluent Weir Gate #2 5 Inoperable due to severe corrosion. 3.3.3 K Flow Control Valve AB1 3 18" manual plug valve operable. n/a Flow Control Valve AB2 3 18" manual plug valve operable. 3.3.3 M Handrails 4 Corrosion at the base of the handrails 3.3.3 D Piping 4 Exposed piping shows corrosion at flanges. 3.3.3 H, I, L, M

Condition Rating 3.8

Condition = 1 Very Good, 2 Good, 3 Fair, 4 Poor, 5 Very Poor

Figure 3.3.3 A

Figure 3.3.3 B

Figure 3.3.3 C Figure 3.3.3 D

Figure 3.3.3 E Figure 3.3.3 F

Figure 3.3.3 G

Figure 3.3.3 H

Figure 3.3.3 I

Figure 3.3.3 J Figure 3.3.3 K

Figure 3.3.3 M

Figure 3.3.3 L

3.3.4 Secondary Clarifiers

The Secondary Clarifier System consists of the following components:

• Clarifier Mechanism

• Clarifier Drive Unit

• Sludge Blanket sensors

System Condition Summary

The secondary clarification system is in fair condition. The drive units for both clarifiers require refurbishment or replacement. The above water components are in fair condition.

Clarifier performance is reported as good.

Component Condition Summary

Clarifier Mechanism

The suction duct, mechanism, scum removal are in fair condition. Peripheral weirs and baffles are level and in fair condition. Handrails and walkways are in good condition. The top rung of the stairway to clarifier 1 is failing due to corrosion.

Clarifier Drive Unit

The drive unit for #1 clarifier shows significant corrosion. Main seal leak appears to be causing failure of bull drive lubrication. The motor housing for clarifier #2 has completely failed and is a safety hazard.

Sludge Blanket Sensors #1 & #2

Sensors are connected to a display and show sludge blanket levels.

Condition Rating Table 3.3.4

Condition

Rating Condition/Performance Comments Photo Reference

#1 Secondary Clarifier Mechanism, Weirs Baffles, Walkway

60ft dia 11 ft SWD. Sludge removal header reported- Fair. Scum arm, trough- Fair. Walkway Fair. Stairway top rung corrosion severe.

3.3.4 A, B, C

#2 Secondary Clarifier Mechanism, Weirs Baffles, Walkway

60ft dia 11 ft SWD. Sludge removal header reported- Fair. Scum arm, trough- Fair. Walkway Fair. No torque indicator.

3.3.4 D

#1 Secondary Clarifier 2 Drive Unit 5 Drive motor corrosion. Bull gear lubrication water intrusion. Corrosion of fasteners and cast iron. No torque indicator.

3.3.4 E

#2 Secondary Clarifier Drive Unit 5 Drive motor housing failed. Exposed motor fan. 3.3.4 G, H Sludge Blanket Sensors #1 & #2 2 New YSI sludge level sensors. Sensor net transmitter. 3.3.4 F

Condition Rating 3.6

Secondary Clarifiers

Figure 3.3.4 A

Figure 3.3.4 B

Figure 3.3.4 D

Figure 3.3.4 C

Figure 3.3.4 E

Figure 3.3.4 G

Figure 3.3.4 H

Figure 3.3.4 F

3.3.5 RAS WAS Pump Station

The RAS WAS Pump Station system consists of the following components:

• RAS pumps

• WAS pumps

• Flow meters

• Gates

• Valves and Piping

• Chemical addition.

System Condition Summary

The RAS WAS pump station is rated fair to poor. This is due to lack of control for RAS flow adjustment because of the manual adjustment required. This prevents flow proportionate RAS flow settings.

One of the WAS pumps is out of service. The handrails above the elevated structure are failing due to corrosion.

The gantry used to remove the RAS and WAS pumps is difficult to operate and is not stable when in use. Scum pumping is via WAS pump.

Component Condition Summary

RAS pumps

RAS pumps are in fair to good condition. One of the RAS pumps has been replaced with a Flygt pump and controller. Pumps are timer and float controlled.

WAS pumps

WAS pumps are in fair to poor condition due to one of the pumps being out of service. Pumps are timer controlled. Valving allows for WAS flow from MLSS line, RAS line, or Clarifier center sump.

Flow meters

The flow meters are in fair to poor condition due to time in service. Performance and accuracy of the RAS flow meters is reported to not be accurate.

Gates

Two sluice gates are available to control flow from the oxidation ditches. Gates are submerged. Anchors for the operating pedestal are severely corroded.

Valves and Piping

Valves and piping are generally in fair condition. There are springs missing on the check valves and one of the check valves is leaking.

Chemical addition.

Chemical addition is not used. The system has been abandoned in place.

Condition Rating Table3.3.5

Condition

Rating Condition/Performance Comments Photo Reference

RAS Pump 1 4 Submersible 10 HP Wemco Hydrostal n/a RAS Pump 2 3 Submersible Flygt n/a RAS Standby Pump 4 Submersible 10 HP Wemco Hydrostal n/a RAS Flow Meter 1 4 6" Sparling Mag meter FS622 3.3.5 D RAS Flow Meter 2 3 6" Sparling Mag meter FS622 3.3.5 F WAS Flow Meter 4 4" Sparling Mag meter FS622 n/a WAS Pump 1 3 Submersible 2 HP Wemco Hydrostal n/a WAS Pump 2 3 Submersible 2 HP Wemco Hydrostal n/a WAS Standby Pump 4 Out of service n/a Secondary Clarifier Chemical Addition Abandoned in place. 3.3.5 B Handrails 4 Upper deck rails failing 3.3.5C Gates 3 Gate pedestal anchors corroded. 3.3.5 E Gantry 4 Gantry is not stable when pulling RAS/WAS pumps 3.3.5 G

Piping & Valves 4 Valves show moderate corrosion. Check valve springs missing. Check valve leaking.

3.3.5 A

Condition Rating 3.6

RAS WAS Pump Station

Figure 3.3.5 A

Figure 3.3.5 C

Figure 3.3.5 D

Figure 3.3.5 B

Figure 3.3.5 E

Figure 3.3.5 F

Figure 3.3.5 G

3.3.6 Chlorine Contact Basins

The Chlorine Contact Basins system consists of the following components:

• Ducking Skimmer

• Gates

System Condition Summary

The chlorine contact basin is used for resettling secondary effluent. Scum is removed via ducking skimmer.

Component Condition Summary

Ducking Skimmer

The ducking skimmer is in fair condition and manually set. Flow from the ducking skimmer flows by gravity to the Thickener Effluent Pump Station.

Gates

Manual sluice gates are in Fair condition. The gates are used to isolate flow to the basins for cleaning.

Condition Rating Table 3.3.6

Asset Description Condition

Rating Condition/Performance Comments Photo Reference

Ducking Skimmer 3 10" Roto-skimmer 3.3.6 A Gates 3 18" x 18" manual sluice gates n/a

Condition Rating 3.0

Chlorine Contact Basin

Figure 3.3.6 A

3.3.7 Ultraviolet (UV) Disinfection System

Ultraviolet (UV) Disinfection System consists of the following components:

• UV System

• Flow Meter

• Shed Enclosure

• Sampler

• Sensors

System Condition Summary

The UV system was installed in 2001. The unit is in fair condition. The wooden shed structure is in fair to poor condition. The structure interferes with movement within the shed. Making maintenance activities difficult. The structure includes flow, pH, temperature, and UTV monitoring.

Component Condition Summary

UV System

The UV system was installed as a separate structure in 2001. The system includes four modules. Each module contains 8 UV lamps. Water level controller and sensor. Hydraulic cleaning system operational. Controls operational. UV transmittance sensor not installed. Cooling pumps are good.

Flow Meter

The flow meter is operational and rated fair.

Shed Enclosure

The shed enclosure is deteriorating due to weather conditions. The doors cannot be secured. The work space is limited requiring doors to be open to perform maintenance.

Sampler

The Effluent sampler is located outside of the shed near the flow metering structure. The sampler is not compliant with sampling requirements due to not being refrigerated.

Sensors pH and temperature monitoring is required. The pH sensor is operational. A Bluetooth enabled temperature probe is installed in the effluent channel.

Condition Rating Table 3.3.7

Condition

Rating Condition/Performance Comments Photo Reference

Trojan UV4000 3

Minor surface corrosion. Maintenance access poor.

Water level controller and sensor good. Hydraulic cleaning system operational. Controls operational. UV transmittance sensor not installed. Cooling pumps are good.

3.3.7 C, D

Flow Meter 3 Flow meter operational. Calibrated Jan 2024. 3.3.7 B

Shed Enclosure 4 Wood deteriorating. Can not secure. UV exposure inside. Door has to be open to perform maintenance.

3.3.7 F

Sampler Sampler not refrigerated 3.3.7 A

Sensors 4 pH probe reads but seems high at 8.56. The other sensors are readings zero or Error.

3.3.7 E

Condition Rating 3.5

Ultraviolet Disinfection

Figure 3.3.7 G

Figure 3.3.7 C

Figure 3.3.7 A

Figure 3.3.7 B

Figure 3.3.7 D

Figure 3.3.7 E Figure 3.3.7 F

3.3.8 Gravity Thickeners

The Gravity thickeners system includes the following components:

• Gravity Thickeners

• Thickener Effluent Pump Station

System Condition Summary

The gravity thickening system is no longer part of the solids processing stream. The mechanical components are not used. The thickener basins are sometimes used to store excess waste solids. Thickener 1 is used as a settling basin for solids thickening. A portable trash pump is used to remove decant which is returned to the thickener effluent pump station. The system is in fair to poor condition.

Component Condition Summary

Gravity Thickeners

Gravity thickener 1 drive and mechanism shows mild corrosion. Gravity thickener 2 shows significant corrosion on the drive and mechanism. The tankage and walkways are in good condition.

Thickener Effluent Pump Station

The thickener pumps are reported to be in good condition. Two flygt pumps replaced the original Wemco submersible pumps. This station can overwhelmed by simultaneous discharges from the decant pump and chlorine contact ducking skimmer.

Condition Rating Table 3.3.8

Condition

Rating Condition/Performance Comments Photo Reference

GT Drive 1 4 Not in service. Mild drive & mechanism corrosion. Tank used for solids thickening. Trash pump removes decant.

3.3.8 A, B, F

GT Drive 2 5 Not in service. Severe drive corrosion. Moderate mechanism corrosion.

3.3.8 C, D

Thickener Effluent PS Pump 1 3 Submersible Flygt pump, float operated.

Thickener Effluent PS Pump 2 3 Submersible Flygt pump. Float operated.

Condition Rating 3.8

Gravity Thickeners

3.3.8 E

Figure 3.3.8 A Figure 3.3.8 B

Figure 3.3.8 D

Figure 3.3.8 C

Figure 3.3.8 E

Figure 3.3.8 F

Figure 3.3.8 G

3.3.9 Aerobic Digesters

The Aerobic Digesters system includes the following components:

• Mixing Turbines

• Aeration Blowers

• Coarse Bubble Diffusers

• Digester Sludge Transfer Pumps

System Condition Summary

The aerobic digester mixing, and aeration system is in fair condition. Two of the mixing turbines have been replaced. Blowers have also been replaced. The mixers exhibit some deflection during operation however this was observed when the basins were about 30% full.

The sludge transfer pumps are in very poor condition due to corrosion. The room housing the pumps is not ventilated creating a corrosive environment.

Component Condition Summary

Mixing Turbines

Mixer 1A exhibits mild defection and noise when in operation. This is an original mixer. Base corrosion due to weather exposure is common on turbine bases. Mixers 2a and 2b have been replaced and are in good condition.

Aeration Blowers

Blowers are in fair to good condition as some of the blowers have been replaced over time. The pressure discs are corroded, and some are laying on the deck corroded. Blower 2a has an air leak on the discharge header.

Coarse Bubble Diffusers

The diffusers were submerged on both basins. The distributed aeration pattern observed indicates fair conditions.

Digester Sludge Transfer Pumps

The digester sludge transfer pumps are in very poor condition. One of the pumps has exposed belt sheave operation which is a safety hazard. Both pumps are reported to be operational. Due to the condition of these pumps maintenance will not improve reliability. The building housing the pumps is not ventilated creating a humid environment conducive to corrosion.

Condition Rating Table 3.3.9

Condition

Rating Condition/Performance Comments Photo Reference

Digester Transfer Sludge Pump 1 5 Severe pump, motor, base corrosion. No ventilation in room.

3.3.9 B, C, D

Digester Transfer Sludge Pump 2 5 Severe pump, motor, base corrosion. No ventilation in room.

3.3.9 A

Turbine 1A 4 Mild shaft deflection during operation. Mixer grinding noise. Surface moderate corrosion. Motor notice doing operation. Thermography, Vibration normal.

3.3.9 D

Blower 1A 3 Sutorbilt PD blower. Newer motor. Mild mounting base corrosion. Thermography, Vibration normal.

3.3.9 E

Turbine 2A 3 Original motor and mixer. Mild corrosion. Mild shaft deflection during operation. Thermography, Vibration normal.

3.3.9 L

Blower 2A 3 Sutorbilt PD blower. Motor Fair. Thermography, Vibration normal. Air leak on discharge piping.

3.3.9 L

Turbine 1B 2 Newer mixer/motor. Base and surface minor corrosion. Thermography, Vibration normal.

3.3.9 F, H

Blower 1B 2 Sutorbilt PD blower. Motor fair. Thermography, Vibration normal.

3.3.9 F, I, J

Turbine 2B 2 Newer mixer/motor. Base and surface minor corrosion. Thermography, Vibration normal.

3.3.9 K

Blower 2B 2 Newer Sutorbilt PD blower. Newer motor. Base Fair.

Thermography, Vibration normal.

3.3.9K

Coarse Bubble Diffusers 3 Aeration patterns indicate no significant failures. 3.3.9 F, G Condition Rating 3.1

Figure 3.3.9 A

Figure 3.3.9 D

Figure 3.3.9 B

Figure 3.3.9 C

Figure 3.3.9 D

Figure 3.3.9 E

Figure 3.3.9 F Figure 3.3.9 G

Figure 3.3.9 H Figure 3.3.9 I

Figure 3.3.9 J

Figure 3.3.9 K Figure 3.3.9 L

3.3.10 Sludge Dewatering

The Sludge Dewatering system includes the following components:

• Feed pump

• Polymer Mixing

• Flow Meter

• Water booster pump

• Belt Filter Press

• Sludge Grinders

System Condition Summary

The dewatering components are contained as a trailer mounted system purchased used in 2012. The dewatering system is fed from aerobic digesters or gravity thickeners. The sludge is conditioned with polymer then fed to the belt filter press. The system is in fair condition but requires a high level of maintenance.

Component Condition Summary

Feed Pump

The feed pump is in fair condition. The shaft coupling guard is off. The coupling adapter is nonstandard.

Typically, a flex coupling would be installed.

Polymer Mixing

The automated polymer system is not in operation. Polymer is mixed via venturi water injection by hand. The venturis, mixers and tanks are in good condition.

Flow Meter

The flow meter is in good condition. The unit is a doppler design which allows for mobility with mounting.

Water Booster Pump

The booster pump is in fair condition.

Belt Filter Press

The belt filter press is in fair condition. Bearing and roller replacement is ongoing. Belts are good. Hydraulic oil seepage throughout.

Condition Rating Table 3.3.10

Condition

Rating Condition/Performance Comments Photo Reference

Feed Pump 3 Shaft guard missing on motor pump connection. Non standard coupling.

3.3.10 H

Polymer System Not Rated. Package polymer system out of service.

Polymer is mixed by hand via venturi water injection.

3.3.10 A

Polymer Mixers 3 Mixers are operational 3.3.10 B, C Polymer Storage tanks 2 Tanks are stainless steel 3.3.10 B, C Flow Meter 2 Doppler DFM. 3.3.10 G Booster Water Pump 3 Motor, pump fair condition. not pictured

Belt Filter Press 3 Belts good. Rollers Fair, some delamination. Minor hydraulic leaks. E-stop at control cabinet. Motors good-one new , gear boxes good. New bearings at mix box.

3.3.10 E, I, F, D

Condition Rating 2.7

Sludge Dewatering

Figure 3.3.10 A Figure 3.3.10 B

Figure 3.3.10 C

Figure 3.3.10 D

Figure 3.3.10 E

Figure 3.3.10 F

Figure 3.3.10 G

Figure 3.3.10 H

Figure 3.3.10 I

3.3.11 Sludge Drying

The Sludge Drying System consists of the following components:

• Feed Conveyor

• Sludge Dryer System

• Dried Sludge Conveyor

• Cooling & Cooling Water

• Odor Control

• Valves

System Condition Summary

The sludge drying system is in fair to good condition. Several components have been replaced or refurbished.

The biggest challenge of the operation is managing the dried cake dust. The dust forms a layer on anything in the room and requires frequent cleaning. Optimization of the vaper water cooling system has resulted in a reduction in temperature from 150 to 200F to a discharge temperature of 70F. The system is producing excellent class A biosolids.

At the time of the assessment many equipment guards were off. This was due to planned maintenance that week. A safety platform has been installed to aid with maintenance.

Component Condition Summary

Feed Conveyor

The feed conveyor is going to be replaced with a unit on site.

Sludge Dryer System

The dryer system is in fair condition. The unit was offline in a “ready” mode during the assessment. The drive end had noise during operation. The gears and chains showed good lubrication. Maintenace was planned for the unit prior to operating again. Exposed gears and chains pose a safety hazard. Covers are on site. Oil heating and internal conveyor are reported to be good. Scale build up in the oil strainer requires frequent maintenance.

System controls and performance are considered good.

Dried Sludge Conveyor

The dried sludge conveyor has some corrosion at the end. Most likely from the vapors off the dried sludge. Some dried cake dust in and around the drive end of the unit. The unit is in fair condition.

Cooling & Cooling Water

The cooling system is in fair condition. Pumps are rebuilt as needed.

Odor Control

The odor system is in good condition as it has been recently refurbished.

Valves

Piping and valves are fair. Temperature protection in place. Newer handwheel knife gate valves.

Condition Rating Table 3.3.11

Condition

Rating Condition/Performance Comments Photo Reference

Feedbox and Conveyor 2 Good condition. Recently repaired. 3.3.11 A

Sludge Dryer 3

Drive end has noise during operation. Gears and chains lubricated. Exposed gears and chains safety hazard. Oil heating and internal conveyor reported good. Scale build up in the oil strainer requires frequent maintenance.

3.3.11 B, C, D

Dried Sludge Conveyor 3 Fair. Mild corrosion on the drive/motor cover. 3.3.11 F, H

Cooling and Cooling Water 3 Pumps and piping in fair condition. Temp in 150-200F, out 70F

3.3.11 C

Odor Control 2 Good condition. Recently refurbished. 3.3.11 C, G

Valves Piping 3 Piping and valves are fair. Temperature protection in place. Newer handwheel knife gate valves.

3.3.11 G

Condition Rating 2.7

Sludge Drying

Figure 3.3.11 A Figure 3.3.11 B

Figure 3.3.11 C

Figure 3.3.11 D Figure 3.3.11 E

Figure 3.3.11 F

Figure 3.3.11 H

Figure 3.3.11 G

3.3.12 Administration Building

The Administration Building System consists of the following components:

• Office

• Mechanical Room

• Storage

• Laboratory

• Bathroom

• Laundry

System Condition Summary

The administration building is in fair condition. The space is small for the number of staff and areas are comingled. There is one bathroom and PPE is stored in the mechanical room. The mechanical room is overburdened with items within the 3ft space requirement for electrical equipment.

The laboratory is a separate room and appears in good working order.

Component Summary

Office

The office area appears in fair condition. There are four work stations including SCADA terminal. There is not a separate space for breaks and eating. The sink and coffee area are located in the work space. Air vents are in poor condition.

Mechanical Room

The mechanical room houses the HVAC system and an electrical control panel. Stored materials are impeding access to the electrical panel.

Storage

Storage is located in the laboratory and in the mechanical room.

Laboratory

The laboratory is in good condition. Ventilation and equipment are in working order.

Bathroom

The one bathroom is in fair condition. Fixtures and floor are showing signs of wear. There is not shower located in the Administration building.

Laundry

The stacked washer and dryer appear in fair condition.

Condition Rating Table 3.3.12

Condition

Rating Condition/Performance Comments Photo Reference

Office 3 Office areas clean. Four work stations, counter, hallway. Air vents show significant wear.

3.3.12 D, I, E, G

Mechanical Room 3 Motor control center access obstructed by storage materials. HVAC in good working condition. SCADA and communication equipment.

3.3.12 A

Storage 2 Laboratory storage 3.3.12 J

Laboratory 2 Lab is clean and organized. Ventilation good. 3.3.12 K

Bathroom 3 One bathroom in good working order 3.3.12 H Laundry 2 Stacked laundry unit in good condition. 3.3.12 H

Condition Rating 2.5

Administration Building

Figure 3.3.12 A Figure 3.3.12 B

Figure 3.3.12 C Figure 3.3.12 D

Figure 3.3.12 F Figure 3.3.12 E

Figure 3.3.12 G

Figure 3.3.12 H

Figure 3.3.12 I Figure 3.3.12 J

Figure 3.3.12 K

3.3.13 Support Systems

The Support Systems System consists of the following components:

• Perimeter Fence

• Plant W3 Water

• Emergency Power

System Condition Summary

Support systems summaries are below.

Component Summary

Perimeter Fence

The perimeter fence is in fair condition overall. There are locations where the fence has been impacted by weather or vehicles.

Plant W3 Water

The plant water pump has a failed motor cover, so the motor fan is spinning without protection. The pump is in fair condition, however the associated piping, valves, and pump base show moderate to severe corrosion. This results in an overall rating of very poor.

City water is the standby source of water should the W3 system fail.

Emergency Power

Standby generators are in fair condition. The enclosure and cover are in good condition. Unit is tested regularly and was serviced in March of 2024. The air inlet plenum insulation is severely degraded.

Condition Rating Table 3.3.13

Asset Description Condition Rating

Condition/Performance Comments Photo Reference

Perimeter Fence 3 Shows fair condition. Some areas where fence is deformed.

3.3.13 B

Plant Water - W3 5 Exposed motor fan. Corrosion, base, valves, piping and pump

3.3.13 A, C, D

Standby Generator 3 Outside good. Last service March 2024. Air inlet plenum shows signs of fire.

3.3.13 E, F, G, H

Condition Rating 3.7

Figure 3.3.13 A

Figure 3.3.13 B

Figure 3.3.13 C

Figure 3.3.13 D

Figure 3.3.13 E Figure 3.3.13 F

Figure 3.3.13 G

Figure 3.3.13 H

3.3.14 Sewage Lift Station System

There are twenty-five lift stations that make up the sewage lift station system. Most of the lift stations are duplex type. Pump station #3 receives flow from most pump stations and is a submersible triplex system.

The city utilizes portable power as standby power for several lift stations. Lift stations including #13, #12, and #8 should be evaluated for onsite standby power.

The following pump station summary is organized by the highest score or most likely to fail. Condition criteria is organized into columns as shown in Table 3.3.14.

Table 3.3.14

Column Definition

Station Identification Lift station number

Description Narrative Description

Capacity Capacity based on operator feedback and data from Jan.

Feb. 2024 runtime data

Wet Well General wet well conditions

Configuration Type of pumping configuration

Controls Condition based on operator feedback and visual inspection.

Pumps Pump condition and status

Standby Power Presence of standby power

Alarms Type of alarm notification

Condition Condition notes

Overall Condition Rating Overall condition rating

Pump Station Condition Table 3.3.14

St…