Wastewater Treatment System Needs Assessment. May 2017

Transcription

1 207 North Stewart Street Geneseo, IL, Wastewater Treatment System Needs Assessment May 2017 Prepared by: Donohue & Associates, Inc South State Street, Suite 1C Champaign, IL, donohue-associates.com Donohue Project No.: 13173

2 City of Geneseo May, 2017 TABLE OF CONTENTS Chapter 1 Executive Summary Overview Recommended Upgrades Cost Opinions... 1 Chapter 2 Project Background Study Objective Facility Overview NPDEs Permit... 5 Chapter 3 Identified Improvements Headworks Excess Flow Pump Station Grit Removal Raw Influent Pumping Primary Treatment Trickling Filters Aeration Final Clarification Secondary Control Building Digestion Dewatering Effluent Pumping Lift Stations Change in Regulations Disinfection Phosphorus Removal Wastewater Needs Assessment Donohue & Associates, Inc. Page ii

3 City of Geneseo May, 2017 LIST OF TABLES Table 2-1 Outfall 001 Limits... 6 Table 2-2 Outfall 004 Limits... 7 Table 2-3 Outfall 005 Limits... 7 Wastewater Needs Assessment Donohue & Associates, Inc. Page iii

4 City of Geneseo May, 2017 LIST OF FIGURES Figure 2-1 Geneseo WWTP and Excess Flow Lagoon Aerial... 4 Figure 2-2 Geneseo WWTP... 5 Figure 3-1 Headworks Building... 8 Figure 3-2 Manual Bypass Bar Screen... 9 Figure 3-3 Mechanically Cleaned Bar Screen... 9 Figure 3-4 Parshall Flume - 12" Figure 3-5 Bar Screening Manual Removal Figure 3-6 Proposed Location of New Screenings Washer and Compactor, Aerial View Figure 3-7 Proposed Location of New Screening washer and Compactor, Outside View Figure 3-8 Butterfly Valve Figure 3-9 Concrete Barrier for Flooding Prevention Figure 3-10 Grit Tank Figure 3-11 Grit Classifier Figure 3-12 Influent Pumps Figure 3-13 Primary Clarifier Figure 3-14 Primary Clarifier Concrete Spalling Figure 3-15 Primary Sludge Pump Figure 3-16 Rock and Plastic Trickling Filters Figure 3-17 Filter Feed Pumps Figure 3-18 Aeration Basins Figure 3-19 Three 15-HP Blowers Figure 3-20 Final Clarifier Figure 3-21 Primary Digester Figure 3-22 Secondary Digester Figure 3-23 Chlorination Basin Wastewater Needs Assessment Donohue & Associates, Inc. Page iv

5 City of Geneseo May, 2017 APPENDICES Appendix A Flow Schematic Appendix B Hydraulic Profile Appendix C NPDES Permit Appendix D Cost Estimates Wastewater Needs Assessment Donohue & Associates, Inc. Page v

6 City of Geneseo May, 2017 ABBREVIATIONS BOD DO GPD GPM IEPA MGD NPDES TSS WWTP Biological Oxygen Demand Dissolved Oxygen Gallon per Day Gallon per Minute Illinois Environmental Protection Agency Million Gallons per Day National Pollutant Discharge Elimination System Total Suspended Solids Wastewater Treatment Plant Wastewater Needs Assessment Donohue & Associates, Inc. Page vi

7 City of Geneseo May, 2017 OVERVIEW CHAPTER 1 EXECUTIVE SUMMARY This study was completed to identify the capital improvements needed at the Geneseo Wastewater Treatment Plant (WWTP), including improvement priority rankings and cost opinions. The study considered the current treatment process and future processes required due to changes in regulation. The Geneseo WWTP was designed and built in the 1970s with the last major improvement occurring in Much of the current equipment is over 20 years old. RECOMMENDED UPGRADES As most of the equipment is over twenty years old, every process requires upgrades, this includes: Headworks Excess flow pumping Grit removal Influent Pumping Primary treatment Trickling filters Aeration Secondary clarification Secondary Control Digestion Dewatering Disinfection Lift Stations New phosphorus removal systems are required to meet the expected upcoming phosphorus limit. COST OPINIONS The estimated current capital cost opinions for process upgrades, in 2017 dollars, are shown below. In addition, the individual cost estimates are included in Appendix D. These cost opinions were developed from a high level view and are considered planning level cost opinions. For planning and budgeting purposes these planning cost opinions have been developed with a significant contingency to allow for adequate planning for the future. Wastewater Treatment Plant Improvements Headworks $887,600 Excess Flow $450,900 Grit $658,400 Influent Pumping $272,500 Primary Clarification $787,600 Trickling Filters $601,700 Wastewater Needs Assessment Donohue & Associates, Inc. Page 1

8 City of Geneseo May, 2017 Aeration Basins $275,400 Secondary Clarification $680,900 Secondary Control $353,200 Digestion - Primary $1,116,300 Digestion - Secondary $1,324,500 Dewatering $674,000 Effluent Pumping $407,000 Disinfection - Lagoon $199,200 Disinfection - UV Plant $1,220,000 Phosphorus Removal $399,200 WWTP SCADA $450,000 WWTP Total $10,758,419 Lift Station Improvements Elk Lift Station $330,000 Chicago Lift Station $330,000 Stewart Lift Station $330,000 Crowe Lift Station $330,000 Jazzercise Lift Station $40,000 Edwards Lift Station $40,000 Ash Lift Station $40,000 Cherry Lift Station $40,000 Prairie Lift Station $40,000 Lift Station Total $1,520,000 Overall Wastewater System Total $12,278,419 These costs have been spread out to 2025 on the Capital Plan spreadsheet included in Appendix D. An Excel spreadsheet has been provided to the City so the City can adjust dates on a year by year basis to allocate funds and plan over a shorter time horizon. The early completion projects are as follows: Dewatering Project This project consists of the installation of a rotary fan press to dewater digested sludge prior to hauling to farm fields for land application. Elk Lift Station This lift station is under design and will be bid out in Disinfection The Illinois EPA (IEPA) has required the City to disinfect all flows to either the Green River or Geneseo Creek. Under previous permits, the City did not need to disinfect due to the option of the two outfalls. A compliance schedule has been negotiated with IEPA with required milestone completion dates. The first key milestone requires plans and specifications, and the IEPA permit to be submitted, by July 1, Wastewater Needs Assessment Donohue & Associates, Inc. Page 2

9 City of Geneseo May, 2017 STUDY OBJECTIVE CHAPTER 2 PROJECT BACKGROUND The objective of this needs assessment is to identify the major capital improvements needed at the Geneseo Wastewater Treatment Plant (WWTP), including improvement priority rankings and high level cost opinions. The report will include current treatment process and future processes required due to changes in regulation. FACILITY OVERVIEW The Geneseo WWTP was designed and built in the 1970s with the last major improvement occurring in Much of the current equipment is over 30 years old and requires replacement due to exceeding the design life of the equipment. The plant was designed for an average flow of 1.5 MGD with a peak flow of 4 MGD. Flow enters the headworks through a mechanically cleaned bar screen and then enters the plant through a 12 parshall flume. Flow above 4 MGD is diverted via a butterfly gate valve to an excess flow pump station. The flow control valve is located upstream of the mechanical bar screen. Excess flow is pumped to a holding lagoon west of the facility. The lagoon only discharges excess flow to Geneseo Creek 3 to 4 times a year, all other times excess flow is sent back to the plant for treatment after the wet weather event has stopped and the treatment plant capacity is available for treatment. After screening, wastewater gravity flows into 10 X10 detritor grit tank, located under the control room. The flow then enters the raw sewage wet well where it is pumped to the primary clarifiers. Grit from the detritor tank is pumped to a grit classifier where it is dewatered and prepared for landfill disposal. Primary treatment is completed through two 50 diameter primary clarifiers. After primary treatment flow is divided between a rock (112 diameter) and plastic (45 diameter) trickling filter. Effluent from the trickling filters can be recycled back into the plastic trickling filter if necessary. Flow then enters a small aeration basin, with a retention time of roughly one hour. The aeration basin is aerated via 3 (2 duty/1 standby) 15 HP blowers. Flow exits the aeration basin and receives final clarification via two (2) 55 diameter secondary clarifiers. Effluent flow from the clarifiers then can either gravity flow to the Geneseo Creek or be pumped to the Green River north of the facility. Pumping to the Green River is done for approximately four months of the year. The sludge produced from the secondary clarifiers is either returned to the aeration basin or sent to digestion. Anaerobic digestion in the plant is completed by two digesters in series. The primary digester is heated and mixed and the secondary digester is unheated and unmixed. Digested sludge is currently removed by liquid hauling to local farm fields for liquid land application. The facility flow schematic can be found in Appendix A, and a hydraulic profile can be found in Appendix B. An aerial view of the facility can be seen in Figure 2-1 and Figure 2-2. Wastewater Needs Assessment Donohue & Associates, Inc. Page 3

10 City of Geneseo May, 2017 Excess Flow Lagoon Geneseo WWTP Figure 2-1 Geneseo WWTP and Excess Flow Lagoon Aerial Wastewater Needs Assessment Donohue & Associates, Inc. Page 4

11 City of Geneseo May, 2017 Final Clarifiers Rock Trickling Filter Plastic Trickling Filter Sludge Drying Beds Aeration Basins Grit Tank Secondary Control Primary Digester Secondary Digester Primary Clarifiers Excess Flow Pumps Parshall Flume Inlet Splitter Structure Figure 2-2 Geneseo WWTP NPDES PERMIT The NPDES Permit limits CBOD and TSS to monthly averages of 20 and 25 mg/l respectively at Outfall 001 and 10 and 12 mg/l respectively at Outfall 004. There are current no effluent limits on total nitrogen or total phosphorus; however, the plant is required to complete a phosphorus removal feasibility study. The Illinois EPA is currently working on new phosphorus requirements that could result in a commitment to achieve chemical phosphorus removal by 2025 or biological phosphorus removal by Recently the Wastewater Needs Assessment Donohue & Associates, Inc. Page 5

12 City of Geneseo May, 2017 WWTP was determined to no longer meet the requirements for disinfection exemption and therefore seasonal disinfection (May to October) will be required. The NPDES permit and the letter from IEPA indicating seasonal disinfection requirement can be found in Appendix C. The effluent limits for Outfall 001, 004 and 005 are shown in Table 2-1, Table 2-2 and Table 2-3. Outfall 001 discharges plant final effluent to the Green River. Outfall 004 discharges plant final effluent to Geneseo Creek. Outfall 005 discharges to Geneseo Creek from the excess flow lagoon. The plant discharges to Outfall 005 approximately 3 to 4 times per year. Outfall 001 Parameter Monthly Average Table 2-1 Outfall 001 (Green River) Limits Load Limits (lb/day) DAF (DMF) Weekly Average Daily Maximum Concentration Limits (mg/l) Monthly Average Weekly Average CBOD 250 (667) 500 (1334) TSS 313 (834) 563 (1501) ph Shall be in range of 6 to 9 standard units Daily Maximum Daily Maximum shall not exceed 400 per 100 ml Fecal Coliform (May through October) Chlorine Residual Ammonia Nitrogen: March 19 (50) 48 (127) 64 (170) April-October 19 (50) 48 (127) 63 (167) Nov.-Feb. 50 (133) 71 (190) Total Phosphorus Monitor only Total Nitrogen Monitor only Monthly Avg. not less than Daily Minimum Dissolved Oxygen March-July N/A August- February Wastewater Needs Assessment Donohue & Associates, Inc. Page 6

13 City of Geneseo May, 2017 Outfall 004 Parameter Monthly Average Table 2-2 Outfall 004 (Geneseo Creek) Limits Load Limits (lb/day) DAF (DMF) Weekly Average Daily Maximum Concentration Limits (mg/l) Monthly Average Weekly Average Daily Maximum CBOD 125 (334) 250 (667) TSS 150 (400) 300 (801) ph Shall be in range of 6 to 9 standard units Fecal Coliform Monitor Only (May through October) Chlorine Residual 0.05 Ammonia Nitrogen: March 19 (50) 48 (127) 64 (170) April- May/Sept.-Oct. 13 (33) 38 (100) June-August 13 (33) 35 (93) 38 (100) Nov. Feb. 33 (87) 71 (190) Total Phosphorus Monitor only Total Nitrogen Monitor only Monthly Avg. not less than Daily Minimum Dissolved Oxygen March-July N/A August- February Table 2-3 Outfall 005 Limits Outfall 005 Concentration Limits (mg/l) Parameter Monthly Average Weekly Average BOD TSS ph Shall be in range of 6 to 9 standard units Fecal Coliform Chlorine Residual 0.75 Ammonia Nitrogen (as N) Total Phosphorus (as P) Daily Maximum Shall Not Exceed 400 per 100 ml Monitor Only Monitor Only Wastewater Needs Assessment Donohue & Associates, Inc. Page 7

14 City of Geneseo May, 2017 CHAPTER 3 IDENTIFIED IMPROVEMENTS The Geneseo WWTP was designed and built in the 1970 s. It was last upgraded in Much of the plant process equipment is over thirty years old. The following sections detail the proposed improvements to the facility. 3.1 HEADWORKS The headworks consists of a mechanically cleaned bar screen, a manual bypass screen and a 12 parshall flume. Currently the screening must be hauled out of the building and up a ramp manual for disposal. The Headworks building is shown in Figure 3-1; the bar screens are shown in Figure 3-2 and Figure 3-3; the parshall flume is shown in Figure 3-4; and the current screening disposal system is shown in Figure 3-5. Figure 3-1 Headworks Building Wastewater Needs Assessment Donohue & Associates, Inc. Page 8

15 City of Geneseo May, 2017 Figure 3-2 Manual Bypass Bar Screen Figure 3-3 Mechanically Cleaned Bar Screen Wastewater Needs Assessment Donohue & Associates, Inc. Page 9

16 City of Geneseo May, 2017 Figure 3-4 Parshall Flume - 12" Figure 3-5 Bar Screening Manual Removal It is recommended that the current screen be replaced with a new screen and auger to lift the screening up and out of the building to the west. The screenings would enter a washer and compactor before disposal. See Figure 3-6 and Figure 3-7 for proposed location. The headworks diverts excess flow (i.e. > 4 MGD) to the lagoon via a flow control valve which is interconnected to the parshall flume flow measurement. The current butterfly gate valve, shown in Figure 3-8, which serves as the control valve, is old and showing signs of corrosion. It is recommended that this valve be replaced with a newer one of the same or equal performance. Wastewater Needs Assessment Donohue & Associates, Inc. Page 10

17 City of Geneseo May, 2017 The block around the headworks building needs to be sealed. In addition, the following are also recommended for replacement as they have exceeded their design life: conduit on the outside of the headworks building; roof on the headworks building; the door to the headworks building. Proposed location of washer and compactor Figure 3-6 Proposed Location of New Screenings Washer and Compactor, Aerial View Figure 3-7 Proposed Location of New Screening washer and Compactor, Outside View Wastewater Needs Assessment Donohue & Associates, Inc. Page 11

18 City of Geneseo May, 2017 Figure 3-8 Butterfly Valve In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace flow control butterfly valve 2. Replace mechanical bar screen and add a washer compactor at grade level 3. Replace the roof and insulation 4. Replace the HVAC equipment for the building 5. Seal block around the block building 6. Replace corroded door and conduit 7. Replace influent composite sampler Wastewater Needs Assessment Donohue & Associates, Inc. Page 12

19 City of Geneseo May, EXCESS FLOW PUMP STATION The excess flow pump station consists of three 6400 gpm pumps that can pump a total of 18.4 MGD (2 duty/1 standby). The pumps currently have soft starts that were put in service in The excess flow is currently pumped 308 feet through a 30 line to manhole #4 where it then flows into 24 line that leads 260 feet into the lagoon. The facility is currently having problems with the manhole over flowing. A concrete surge tower, shown in Figure 3-9, has been built to mitigate the surge. Since the original gravity flow piping was not designed for this pressure condition, there is leakage near the surge tower which is undermining the foundation. It is recommended that the manhole be removed and either be replaced with an elbow fitting to connect the 30 and 24 pipes or a better designed surge tower to accommodate the short term spike in the hydraulic grade line. It is also recommended to replace the soft starts with VFDs to attenuate the flow surge. A more detailed hydraulic evaluation should be completed to make sure the improvements do not cause a backup to the primary clarifier bypass structure. Figure 3-9 Concrete Surge Tower In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace the current excess flow pumps with new pumps 2. Replace the aged soft starts with new VFD s for surge attenuation 3. Replace mag meter that controls return flow from the lagoon 4. Hydraulic evaluation and replacement of concrete surge tower to avoid washout and collapse Wastewater Needs Assessment Donohue & Associates, Inc. Page 13

20 City of Geneseo May, GRIT REMOVAL Grit removal is currently performed by a 10 x10 detritor, shown in Figure Grit is pumped to a grit classifier via a 210 gpm grit pump, shown in Figure All of the grit equipment is original and past the design life. Therefore it is recommended that all grit equipment be replaced with similar equipment. The door and door jamb to the control building where the grit tank is located should also be replaced due to significant corrosion. The gates in the channel to the grit tank will need to be replaced as well. Figure 3-10 Grit Tank Wastewater Needs Assessment Donohue & Associates, Inc. Page 14

21 City of Geneseo May, 2017 Figure 3-11 Grit Classifier In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace the current detritor equipment in the lower grit removal tank 2. Replace the grit slurry pump with a new grit slurry pump 3. Replace the grit classifier with a new grit classifier 4. Replace stop gates in the channels with new stop gates to allow grit tank isolation 5. Replace corroded door Wastewater Needs Assessment Donohue & Associates, Inc. Page 15

22 City of Geneseo May, RAW INFLUENT PUMPING After grit removal raw influent is pumped to primary treatment via three pumps, two of which are original to the plant and one which was installed in The two original pumps have capacities of 1250 and 2000 gpm. The newer pump has a capacity of 860/1750 gpm. Due to exceeding their design life it is recommended that all three pumps be replaced and that new VFDs be installed. In addition, all gates, valves and diffusers are recommended for replacement. Influent pumps are shown in Figure Figure 3-12 Influent Pumps In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace the current influent pumps with new influent pumps 2. Install VFD s for the new influent pumps 3. Replace the pump isolation valves 4. Replace the pump check valves Wastewater Needs Assessment Donohue & Associates, Inc. Page 16

23 City of Geneseo May, PRIMARY TREATMENT Primary treatment consists of two primary clarifiers, one shown in Figure 3-13, with diameters of 50. The handrails were originally embedded into the concrete and are causing concrete spalling, as shown in Figure In addition, the scum trough is currently held in place via clamps. The primary internal mechanisms were replaced between 2010 and 2012 and are expected to last until at least It is recommended that the concrete be repaired and the handrails be replaced with a non-embedded aluminum railing. The primary sludge pump should also be replaced at this time due exceeding the design life. Primary sludge pumping is shown in Figure In addition the six 6 plug valves in the sludge pit between the two clarifiers are due for replacement. Figure 3-13 Primary Clarifier Wastewater Needs Assessment Donohue & Associates, Inc. Page 17

24 City of Geneseo May, 2017 Figure 3-14 Primary Clarifier Concrete Spalling Figure 3-15 Primary Sludge Pump In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace the current clarifier equipment with new clarifier equipment 2. Replace handrail and repair concrete 3. Replace plug valves and primary sludge pump Wastewater Needs Assessment Donohue & Associates, Inc. Page 18

25 City of Geneseo May, TRICKLING FILTERS There are currently two trickling filters in use at the facility. The original 112 diameter rock trickling filter and the newer 45 diameter plastic media trickling filter, both are shown in Figure The distributor arms for both the rock and plastic media filters were replaced approximately ten years ago. It is recommended that distribution arms be replaced approximately once every ten to fifteen years and therefore a replacement is recommended. It should be noted that the center assembly may be leaking due to age and wear and tear. For budgetary purposes this should be included as a replacement cost. The plastic media and the rock media are currently not showing signs of sagging which would indicate crushed media below. Therefore the media appears to be in relatively good shape for it s age. The fixed film aspect of the trickling filter allows for efficient BOD and ammonia removal with low energy costs. The limitation of this technology is that it will be difficult to achieve biological phosphorus removal and biological nitrogen removal. Since the current strategy by IEPA for phosphorus and nitrogen removal may require phosphorus removal by 2025 and nitrogen removal after 2035, it is recommended to upgrade the current system until nitrogen limits become a reality. The three filter feed pumps, at 1200 gpm each, are original to the plant and therefore should be replaced due to exceeding the design life. The filter pumps are shown in Figure There are currently two Flygt pumps that are greater than 10 years old. Plastic Trickling Filters Rock Trickling Filters Filter Feed Pumps Figure 3-16 Rock and Plastic Trickling Filters Wastewater Needs Assessment Donohue & Associates, Inc. Page 19

26 City of Geneseo May, 2017 Figure 3-17 Filter Feed Pumps In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace distributor arms for the rock filter and plastic media filter 2. Replace the center assembly 3. Replace the filter feed pumps Wastewater Needs Assessment Donohue & Associates, Inc. Page 20

27 City of Geneseo May, AERATION The current aeration basin has a volume of approximately 9000 cu-ft and an average detention time of one hour. Aeration is provided by three 15-HP blowers, shown in Figure 3-19, all blowers are recommended for upgrades. The existing Wyss diffusors are current being replaced. All channels and gates in both tanks as well as all slide gates are recommended for replacement as well. Figure 3-18 Aeration Basins Wastewater Needs Assessment Donohue & Associates, Inc. Page 21

28 City of Geneseo May, 2017 Figure 3-19 Three 15-HP Blowers In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace positive displacement blowers with new blowers 2. Replace gates in aeration tanks Wastewater Needs Assessment Donohue & Associates, Inc. Page 22

29 City of Geneseo May, FINAL CLARIFICATION Final clarification is completed by two 55 diameter clarifiers, which were part of the 1986 construction. One clarifier is shown in Figure The clarifier drives were replaced between 2014 and 2015 and do not need replacement. The support arm on the west clarifier is recommended for replacement. Due to exceeding the design life it is recommended that all clarifier mechanisms be scheduled for replacement within the next 10 years. Figure 3-20 Final Clarifier In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace clarifier mechanisms within the next 10 years Wastewater Needs Assessment Donohue & Associates, Inc. Page 23

30 City of Geneseo May, SECONDARY CONTROL BUILDING Return activated sludge pumping is completed by three 500 gpm pumps. Waste activated sludge pumping is completed by one 145 gpm pump. The secondary control building houses all of the RAS and WAS pumping, including: 1 waste sludge pump 3 return sludge pumps VFDs It is recommended that all sludge pumping be replaced with the same or similar equipment. The control building also contains non-potable water system pumps and a hydropneumatic tank which have reached the end of their design life. It is recommended that the pumps and the tank be replaced. In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace RAS and WAS pumps 2. Replace VFD s with new VFD s 3. Replace non-potable water system and hydropneumatic tank Wastewater Needs Assessment Donohue & Associates, Inc. Page 24

31 City of Geneseo May, DIGESTION Digestion is currently being completed through two stage anaerobic digestion. The primary digester uses heat and mixing, while the secondary digester does not. Both digesters are original to the plant; however the primary digester s lid was replaced in 1986 as shown in Figure It is recommended that the secondary digester s lid, shown in Figure 3-22, be replaced and that the primary digester s lid be re-coated. The gas safety equipment for both digesters should be updated and it is recommended that the current budget be modified to include regular digester cleanings. The digester building also contains: 1 sludge transfer pump 1 sludge heater pumps Sludge heat exchanger Gas safety equipment It is recommended that both pumps be replaced with the same or similar equipment. Figure 3-21 Primary Digester Wastewater Needs Assessment Donohue & Associates, Inc. Page 25

32 City of Geneseo May, 2017 Figure 3-22 Secondary Digester In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace secondary digester lid 2. Re-coat primary digester lid 3. Replace sludge heat exchanger with new sludge heat exchanger 4. Replace sludge transfer pump (part of dewatering project) 5. Replace current digester mixing system in the primary digester with new digester mixing system 6. Replace the current gas safety equipment with new gas safety equipment Wastewater Needs Assessment Donohue & Associates, Inc. Page 26

33 City of Geneseo May, DEWATERING Dewatering was done in the past using the vacuum assisted drying beds; however, problems with the drying beds have led to sludge being land applied in its liquid state. Due to resistance from the agricultural community a new dewatering system should be installed. The City has already completed a dewatering study, completed by Donohue & Associates, Inc., which recommended the installation of a rotary fan press. Based on the study, the WWTP currently produces 600,000 gallons per year of digested sludge, leading to approximately 200,000 pounds per year of dry solids. The plant staff would like to dewater one day (6-8 hours) every other week for a total of 156 to 208 hours per year. This required a minimum hydraulic capacity of 48 gpm and dry solids capacity of 962 pounds per hour. Both rotary fan presses and screw presses were investigated. Based on economic analysis the rotary fan press would be lower in both capital costs and annual costs. In addition, the fan press has a smaller footprint leading to an easier installation. The fan press initial overall project capital cost including installation would be $674,000, based on a quote from March 2014 converted to December 2016 dollars. In summary, the recommended improvements for dewatering equipment are as follows: 1. Install rotary fan press dwatering unit 2. Replace sludge transfer pump with new transfer pump to meet the requirements of the rotary fan press 3. Install a new emulsified polymer addition system for the rotary fan press 3.12 EFFLUENT PUMPING Effluent pumping is utilized approximately 4 months of the year, November through February, to pump flow to the Green River. Effluent pumping is completed only to exercise the pumps. Currently there are three 1800 gpm pumps that are original to the facility. While these pumps are not used frequently it is recommended that they be replaced with the same or similar equipment and VFDs be installed. Note that a gravity line was added during the 1986 improvements. Due to high water levels in Geneseo Creek during heavy wet weather events, it is sometimes not possible to gravity flow to the Creek. In addition, with the additional future requirement for disinfection, there will be no advantage for discharging to Geneseo Creek versus the Green River. Since the effluent limits at the Green River outfall are less stringent, and since the disinfection system will require pumped flow to function, the effluent pumps will need to be used year round. In summary, the recommended improvements due to age and deterioration of equipment are as follows: 1. Replace effluent pumps with new effluent pumps 2. Install VFD s with new effluent pumps 3. Replace the isolation and check valves for each pump Wastewater Needs Assessment Donohue & Associates, Inc. Page 27

34 City of Geneseo May, LIFT STATIONS There are currently 9 lift stations throughout the collection system, consisting of 4 dry pit lift stations and 5 submersible pump stations. The dry pit lift stations include: Elk Lift Station Chicago Lift Station Stewart Lift Station Crowe Lift Station The submersible pump stations include: Jazzercise Lift Station Edwards Lift Station Ash Lift Station Cherry Lift Station Prairie Lift Station It is recommended that all of the dry pit lift stations be upgraded to submersible pump stations for ease of maintenance and safety. The control systems at the submersible pump lift stations should be replaced with more modern control systems ELECTRICAL AND CONTROL SYSTEMS The existing treatment plant was last upgraded in There have been significant changes to electrical codes since this upgrade and it is expected that with each individual project significant electrical upgrades could be required. Therefore, while some dollars for electrical have been accounted for, the contingency for each project was set at 30% due to the high level nature of the cost opinions for each project. In terms of SCADA, which stands for Supervisory Control and Data Acquisition, the existing treatment has very limited SCADA capabilities. We have included a line item in the overall cost opinion to account for a stand alone SCADA implementation project CHANGE IN REGULATIONS While the WWTP does not currently have disinfection or phosphorus removal requirements, new NPDES Permit will require seasonal disinfection, as indicated by the letter from IEPA shown in Appendix C, and phosphorus removal. The completion of a phosphorus removal feasibility study in anticipation of an upcoming phosphorus limit is currently being completed DISINFECTION The facility currently has a gas chlorination system, located next to the control building. This system has not been in services for several years and is in considerable disrepair. The gaseous chlorine had been delivered in one ton cylinders in the past. Due to the potential dangers of gaseous chlorine, and the Wastewater Needs Assessment Donohue & Associates, Inc. Page 28

35 City of Geneseo May, 2017 considerable revisions to the chemical feed facilities required, the City is desiring to use ultraviolet disinfection to meet the future disinfection requirements. The excess flow lagoon currently has no disinfection capabilities. During the ultraviolet disinfection improvements, a small chemical feed facility will be installed near the lagoon overflow point to allow for disinfection before it overflows to the Geneseo Creek. Chlorination Basin Figure 3-23 Chlorination Basin PHOSPHORUS REMOVAL While a phosphorus limit is not currently in place, a phosphorus limit compliance schedule is expected on the next issued NDPES permit. This compliance schedule will most likely require chemical phosphorus removal by While no upgrades are needed at this time, it is recommended that phosphorus removal alternative be considered during plant upgrades. Since biological phosphorus removal is not feasible for this treatment plant a chemical addition system will need to be added. It is anticipated this system will consist of a 2,000 gallon storage tank and an alum chemical feed system. The phosphorus removal chemical feed system will be installed in a new chemical feed building. Wastewater Needs Assessment Donohue & Associates, Inc. Page 29

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37 Date SLUDGE DRYING BEDS Checked By RETURN FLOW METERING EXCESS FLOW LAGOON FLOW CONTROL VALVE BYPASS SLUDGE HEATING PUMPING 150 GPM) TRANSFER SLUDGE PUMPING 150 GPM) PRIMARY DIGESTER SECONDARY DIGESTER SLUDGE DISCHARGE PUMPING 420 GPM, 75 GPM) LIQUID SLUDGE TO LAND APPLICATION WASTE SLUDGE PUMPING 145 GPM) RETURN SLUDGE PUMPING 500 GPM) VACUUM ASSISTED SLUDGE BEDS FINAL CLARIFIERS (2 TANKS, DIAMETER 55', SWD 14.5') (SURFACE SETTLING RATE (ADF) 316 GAL/D/SQF) SECONDARY CLARIFIER 1 SUPERNATANT RETURNED TO RAW SEWAGE PUMP STATION DEWATERED SLUDGE TO LAND FILL OR LAND APPLICATION Revision Description Drawn By AERATED CHAMBER (2 BASINS, TOTAL VOLUME 9072 CU FT) EFFLUENT PUMPING 1800 GPM) FLOW MEASUREMENT H FLUME EXCESS FLOW PUMPING (3 PUMPS) (CAPACITY EACH 6400 GPM) GRIT TO LANDFILL GRIT CLASSIFIER/ WASHER RAW SLUDGE PUMPING 100 GPM) PRIMARY CLARIFIERS (2 TANKS, 50' DIAMETER) (VOLUME EACH 183,949 GAL) FILTER FEED PUMP GPM) AERATED CHANNEL BYPASS SECONDARY CLARIFIER 2 EFFLUENT WET WELL CHLORINE CONTACT TANKS OUTFALL 001 TO GREEN RIVER Revision Number Designed By Drawn By Checked By Approved By XX1 XX2 XX3 XX4 EXCESS FLOW RETURN MANUAL BAR SCREEN MANUAL BAR SCREEN GRIT SEPARATOR GRIT PUMPING 210 GPM) PRIMARY CLARIFIER 1 PLASTIC MEDIA TRICKLING FILTER (DIAMETER 45') (MEDIA DEPTH 7.5') (MEDIA VOLUME 28.6 KCF) WASTEWATER Filename Project No. Project Date 009N1.DWG /2017 SLUDGE PLANT INFLUENT INLET SPLITTER FLOW CONTROL VALVE MECHANICAL BAR SCREEN (TOTAL CAPACITY: 4.2 MGD) 12" PARSHALL FLUME GRIT TANK (VOLUME: 225 CU FT) (DETENTION TIME (ADF) 1.8 MIN) INFLUENT PUMPING (3 PUMPS) 1250 GPM) 1750 GP,M) 2000 GPM) PRIMARY CLARIFIER 2 FLOW SPLITTER ROCK TRICKLING FILTER (DIAMETER 112', MEDIA DEPTH 18') (MEDIA VOLUME 73.9 KCF) CITY OF GENESEO CAPITAL IMPROVEMENT PLAN GENESEO WASTEWATER TREATMENT PLANT FLOW SCHEMATIC Sheet No. Drawing No. Drawing Number

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39 Checked By Date Revision Description Drawn By TOP OF BERM HWL OVERFLOW SPILLWAY " EXCESS FLOW HOLDING LAGOON MH TOC EXCESS FLOW RETURN INLET FLOW SPLITTER AND EXCESS FLOW BYPASS PUMPS EXCESS FLOW INFLUENT PUMPS EXCESS FLOW CHANNEL W/ BAR SCREEN AND H. FLUME TOC " TOC PLANT INFLUENTS MECHANICAL BAR SCREEN TOC POINT OF V-NOTCH WEIR TOC " TOC " TOC " HWL 16" 16" BOTTOM OF GENESEO UNDERDRAIN CREEK INV HWL " INV LWL INV LWL LWL " TO GREEN INV RAW SEWAGE INV RIVER BYPASS 12" PARSHALL PUMPS 4" CONTROL FLUME 18" 24" VALVE GRIT CHAMBER RAW SEWAGE PRIMARY CLARIFIERS TRICKLING FILTER ROCK TRICKLING FILTER PLASTIC MEDIA AERATED AERATED 30" WET WELL FEED PUMPS TRICKLING FILTER CHANNEL CHANNEL AERATED EFFLUENT PUMPS CHAMBER TOC DIST. ARM TOP OF ROCK TOC TOP OF MEDIA BOTTOM OF MEDIA BOTTOM OF UNDERDRAIN INV TOC TOC SET WEIR FINAL CLARIFIERS CHLORINE CONTACT TANK TOC Revision Number Designed By Drawn By Checked By Approved By Filename Project No. Project Date CITY OF GENESEO CAPITAL IMPROVEMENT PLAN XX1 XX2 XX3 XX4 001GX1.DWG /2017 GENESEO WASTEWATER TREATMENT PLANT HYDRAULIC PROFILE Sheet No. Drawing No. Drawing Number

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41 NPDES Permit No. IL Notice No. SKT: bah Public Notice/Fact Sheet Issued By: Public Notice Beginning Date: July 15, 2016 Public Notice Ending Date: August 15, 2016 National Pollutant Discharge Elimination System (NPDES) Permit Program PUBLIC NOTICE/FACT SHEET of Draft Reissued NPDES Permit to Discharge into Waters of the State Illinois EPA Division of Water Pollution Control Permit Section 1021 North Grand Avenue East Post Office Box Springfield, Illinois / Name and Address of Discharger: City of Geneseo 115 South Oakwood Avenue Geneseo, Illinois Name and Address of Facility: City of Geneseo STP 207 North Stewart Street Geneseo, Illinois (Henry County) The Illinois Environmental Protection Agency (IEPA) has made a tentative determination to issue a NPDES Permit to discharge into the waters of the state and has prepared a draft Permit and associated fact sheet for the above named discharger. The Public Notice period will begin and end on the dates indicated in the heading of this Public Notice/Fact Sheet. All comments on the draft Permit and requests for hearing must be received by the IEPA by U.S. Mail, carrier mail or hand delivered by the Public Notice Ending Date. Interested persons are invited to submit written comments on the draft Permit to the IEPA at the above address. Commentors shall provide his or her name and address and the nature of the issues proposed to be raised and the evidence proposed to be presented with regards to those issues. Commentors may include a request for public hearing. Persons submitting comments and/or requests for public hearing shall also send a copy of such comments or requests to the Permit applicant. The NPDES Permit and notice numbers must appear on each comment page. The application, engineer's review notes including load limit calculations, Public Notice/Fact Sheet, draft Permit, comments received, and other documents are available for inspection and may be copied at the IEPA between 9:30 a.m. and 3:30 p.m. Monday through Friday when scheduled by the interested person. If written comments or requests indicate a significant degree of public interest in the draft Permit, the permitting authority may, at its discretion, hold a public hearing. Public notice will be given 45 days before any public hearing. Response to comments will be provided when the final Permit is issued. For further information, please call Surinder Tandon at 217/ The following water quality and effluent standards and limitations were applied to the discharge: Title 35: Environmental Protection, Subtitle C: Water Pollution, Chapter I: Pollution Control Board and the Clean Water Act were applied in determining the applicable standards, limitations and conditions contained in the draft Permit. The applicant is engaged in treating domestic wastewater for the City of Geneseo. The length of the Permit is approximately 5 years. The effluent is discharged to the Green River through outfall 001 or to Geneseo Creek through outfall 004. The seven day once in ten year low flow (7Q10) of Green River is 46.1 cfs. The seven day once in ten year low flow (7Q10) of Geneseo CreeK is 0.03 cfs. The design average flow (DAF) for the facility is 1.5 million gallons per day (MGD) and the design maximum flow (DMF) for the facility is 4.0 MGD. Treatment consists of screening, grit removal, primary clarifiers, activated sludge, trickling filters, final clarifiers and chlorination. Sludge is treated by anaerobic digestion, drying beds and then land applied.

42 Public Notice/Fact Sheet -- Page 2 -- NPDES Permit No. IL This Reissued Permit does not increase the facility s DAF, DMF, concentration limits, and/or load limits. Pursuant to the waiver provisions authorized by 40 CFR , this draft permit is within the class, type, and size for which the Regional Administrator, Region V, has waived his right to review, object, or comment on this draft permit action. This Permit recognizes and continues the year-round disinfection exemption approved by the IEPA on June 29, 1989 and included in past NPDES permit actions since that date. It is the IEPA s tentative decision that under Illinois Pollution Control Board regulations, the following reach of waterbody is not classified for primary contact use activities and is not subject to the fecal coliform water quality standard of 35 Ill. Adm. Code This draft permit does not contain requirements for disinfection of the discharge from discharge numbers(s) 004. Geneseo Creek, from the facility discharge in Section 17, T17N, R3E, to the confluence with Green River has been determined to be unsuited to support primary contact activities (swimming) due to physical, hydrologic or geographic configuration. Anyone knowing of primary contact activities occurring within this water segment is invited to submit comments to the IEPA. Comments should give the nature of the activities (i.e swimming, fishing, canoeing, etc.), the location and months of the year when these activities have been observed. The IEPA is also interested in obtaining information on the proximity of residential dwellings and the accessibility of the public to this water segment. Anyone with such information is asked to submit comments to the IEPA on this draft permit action. Instructions for submitting comments are contained earlier in this document. Application is made for the existing discharge(s) which are located in Henry County, Illinois. The following information identifies the discharge point, receiving stream and stream classifications: Discharge Number Receiving Stream Latitude Longitude Stream Classification Integrity Rating 001 Green River North West General Use Not Rated 004 Geneseo Creek North West General Use Not Rated 005 Geneseo Creek North West General Use Not Rated To assist you further in identifying the location of the discharge(s) please see the attached map. Green River, Waterbody Segment PB-09, is listed on the draft 2014 Illinois Integrated Water Quality Report and 303(d) List as impaired. The following parameters have been identified as the pollutants causing impairment: Potential Causes Unknown Uses Impaired Aquatic life Outfall 004 from the subject facility discharges to Geneseo Creek at a point where 0.03 cfs of flow exists upstream of the outfall during critical 7Q10 low-flow conditions. Geneseo Creek is classified as a General Use Water at this location. Geneseo Creek (segment PBE-01) is listed on the draft 2014 Illinois Integrated Water Quality Report and Section 303(d) List as an impaired water body for aquatic life use. The causes of impairment are given as alteration of stream-side vegetative cover (non-pollutant) and sedimentation/siltation. Geneseo Creek at this location has not been given an integrity rating in the 2008 Illinois Department of Natural Resources Publication Integrating Multiple Taza in Biological Stream Rating System. Geneseo Creek is not designated as an enhanced water pursuant to the dissolved oxygen water quality standard at this location. The next downstream segment is P-25, Rock River, and is listed on the draft 2014 Illinois Integrated Water Quality Report and Section 303(d) List as impaired for aquatic life and fish consumption uses. The cause of aquatic life use impairment is cause unknown. The causes of fish consumption use impairment are mercury and PCBs. Aesthetic quality use was not assessed. The next downstream segments are on the Mississippi River. All Illinois segments of the Mississippi River are fully supportive of aquatic life and aesthetic quality uses. There are no downstream instances of impairment due to aquatic algae, aquatic plants or dissolved oxygen.

43 Public Notice/Fact Sheet -- Page 3 -- NPDES Permit No. IL The discharge(s) from the facility is (are) proposed to be monitored and limited at all times as follows: Discharge Number(s) and Name(s): 001 STP Outfall Load limits computed based on a design average flow (DAF) of 1.5 MGD (design maximum flow (DMF) of 4.0 MGD). The effluent of the above discharge(s) shall be monitored and limited at all times as follows: LOAD LIMITS lbs/day DAF (DMF)* CONCENTRATION LIMITS mg/l Parameter Monthly Average Weekly Average Daily Maximum Monthly Average Weekly Average Daily Maximum Regulation CBOD 5** 250 (667) 500 (1334) IAC CFR Suspended Solids** 313 (834) 563 (1501) IAC CFR ph Shall be in the range of 6 to 9 Standard Units 35 IAC Fecal Coliform Daily Maximum shall not exceed 400 per 100 ml (May through October) 35 IAC Chlorine Residual IAC Ammonia Nitrogen: March 19 (50) 48 (127) 64 (170) April-October 19 (50) 48 (127) 63 (167) Nov.-Feb. 50 (133) 71 (190) IAC 355 and 35 IAC 302 Total Phosphorus (as P) Monitor only 35 IAC Total Nitrogen Monitor only 35 IAC Monthly Avg. not less than Weekly Avg. not less than Daily Minimum Dissolved Oxygen March-July N/A IAC August-February *Load Limits are calculated by using the formula: 8.34 x (Design Average and/or Maximum Flow in MGD) x (Applicable Concentration in mg/l) **BOD 5 and Suspended Solids (85% removal required): In accordance with 40 CFR 133, the 30-day average percent removal shall not be less than 85 percent.

44 Public Notice/Fact Sheet -- Page 4 -- NPDES Permit No. IL The discharge(s) from the facility is (are) proposed to be monitored and limited at all times as follows: Discharge Number(s) and Name(s): 004 STP Outfall Load limits computed based on a design average flow (DAF) of 1.5 MGD (design maximum flow (DMF) of 4.0 MGD). The effluent of the above discharge(s) shall be monitored and limited at all times as follows: LOAD LIMITS lbs/day DAF (DMF)* CONCENTRATION LIMITS mg/l Parameter Monthly Average Weekly Average Daily Maximum Monthly Average Weekly Average Daily Maximum Regulation CBOD 5** 125 (334) 250 (667) IAC CFR Suspended Solids** 150 (400) 300 (801) IAC CFR ph Shall be in the range of 6 to 9 Standard Units 35 IAC Fecal Coliform Monitor only (May through October) 35 IAC Chlorine Residual IAC Ammonia Nitrogen: March. 19 (50) 48 (127) 64 (170) April-May/Sept.-Oct. 13 (33) 38 (100) June-August 13 (33) 35 (93) 38 (100) Nov.-Feb. 33 (87) 71 (190) IAC 355 and 35 IAC 302 Total Phosphorus (as P) Monitor only 35 IAC Total Nitrogen Monitor only 35 IAC Monthly Avg. not less than Weekly Avg. not less than Daily Minimum Dissolved Oxygen March-July N/A IAC August-February *Load Limits are calculated by using the formula: 8.34 x (Design Average and/or Maximum Flow in MGD) x (Applicable Concentration in mg/l) **BOD 5 and Suspended Solids (85% removal required): In accordance with 40 CFR 133, the 30-day average percent removal shall not be less than 85 percent.

45 Public Notice/Fact Sheet -- Page 5 -- NPDES Permit No. IL This Permit contains an authorization to treat and discharge excess flow as follows: Discharge Number(s) and Name(s): 005 Excess Flow Lagoon Outfall (Flows in excess of 2777 gpm) The effluent of the above discharge(s) shall be monitored and limited at all times a follows: CONCENTRATION LIMITS (mg/l) Parameter Monthly Average Weekly Average Regulation BOD 5* CFR Suspended Solids* CFR Fecal Coliform Daily Maximum Shall Not Exceed 400 per 100 ML 35 IAC ph Shall be in the range of 6 to 9 standard units 35 IAC Chlorine Residual IAC Ammonia Nitrogen (as N) Monitor only 35 IAC Total Phosphorus (as P) Monitor only 35 IAC *The 30-day average percent removal shall not be less than 85 percent.

46 Public Notice/Fact Sheet -- Page 6 -- NPDES Permit No. IL This draft Permit also contains the following requirements as special conditions: 1. Reopening of this Permit to include different final effluent limitations. 2. Operation of the facility by or under the supervision of a certified operator. 3. Submission of the operational data in a specified form and at a required frequency at any time during the effective term of this Permit. 4. More frequent monitoring requirement without Public Notice. 5. Prohibition against causing or contributing to violations of water quality standards. 6. Recording the monitoring results on Discharge Monitoring Report Forms using one such form for each outfall each month and submitting the forms to IEPA each month. 7. The provisions of 40 CFR Section (m) & (n) are incorporated herein by reference. 8. Effluent sampling point location. 9. Controlling the sources of infiltration and inflow into the sewer system. 10. A requirement to monitor and a limit of 0.05 mg/l for residual chlorine when it is used. 11. Seasonal fecal coliform limits. 12. Monitoring for arsenic, barium, cadmium, hexavalent chromium, total chromium, copper, available cyanide, total cyanide, fluoride, dissolved iron, total iron, lead, manganese, mercury, nickel, oil, phenols, selenium, silver and zinc is required to be conducted semi-annually beginning 3 months from the effective date. 13. Submission of annual fiscal data. 14. A requirement for biomonitoring of the effluent. 15. Submission of semi annual reports indicating the quantities of sludge generated and disposed. 16. Capacity, Management, Operations, and Maintenance (CMOM) plan. 17. Reopening of this Permit to include revised effluent limitations based on a Total Maximum Daily Load (TMDL) or other water quality study. 18. Phosphorus Reduction Feasibility Plan 19. Phosphorus Removal Optimization Plan

47 Public Notice/Fact Sheet -- Page 7 -- NPDES Permit No. IL