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HomeMy WebLinkAboutItem #07 Sanitary Sewer Collection System Inflow & Infiltration Study ire Centex of Good Liy CQE f - 8 AGENDA ITEM COVER SHEET Meeting Date: May 1, 2012 Item # Reviewed By: Contact Name: Charles K. Smith, P.E. Department Director: Charles K. S i Contact Number: 407 - 905 -3159 City Manager: Robert Frank /r //i'P Subject: Sanitary Sewer Collection System Inflow & Infiltration Study Background Summary: The City of Ocoee Wastewater Treatment Plant has experienced increased influent flows during the wet weather season. Wet weather flows are usually prolonged and steady through out the system and are generally caused by a higher- than - normal water table, leading to the groundwater leaching into the system through pipe joints, sewer laterals and structures. Likewise, a high intensity /short duration rainfall event, especially exacerbated in wet weather season, can lead to localized flooding which results in sewer collection facilities being inundated with water. The inflow from the flooding is more intense, short in duration and can be problematic. To ensure the City's wastewater system is properly maintained and operated, Staff is recommending a systematic review of its sewer system by way of I &I (inflow and infiltration) studies. The first study staff recommends will cover the areas that contribute flows to lift stations #10 and #12. Lift station #10 includes the auto auction and industrial area along Enterprise Street. Staff will utilize the services of Reiss Engineering, Inc., the City's hydraulic modeling and engineering planning consultant to map, perform invasive -smoke testing, measure flows in inverts of structures, and determine baseline flows (dry weather) and wet weather flows. The consultant will recommend and attend the televising and recording of underground pipe and facilities. The deliverable for the study shall be a report of findings which identifies issues and recommended corrections, prioritized. Issue: Should City Commission authorize the City Manager to cause a Sanitary Sewer Collection System Infiltration & Inflow Study for the Enterprise Street and South Maguire Road areas? Recommendations Motion to authorize the City Manager to approve the "I &I Reduction for Lift Station Area 10 and 12" study with Reiss Engineers Inc. in the amount of $49,150.00. Attachments: Reiss Scope of Services "I &I Reduction for Lift Station Areas 10 and 12 ". 1 . Financial Impact: The Fiscal Year 2011 -2012 approved budget includes in Professional Services (401- 531 -00 -3128) $35,000 for an Infiltration Study, and $30,000 for a Maintenance Flushing Program. Staff has undertaking the maintenance program internally, making the additional $14,150.00 available for the I &I study. Type of Item: (please mark with an x') Public Hearing For Clerk's Dept Use: Ordinance First Reading X Consent Agenda Ordinance Second Reading Public Hearing Resolution Regular Agenda X Commission Approval Discussion & Direction Original Document/Contract Attached for Execution by City Clerk Original Document/Contract Held by Department for Execution Reviewed by City Attorney N/A Reviewed by Finance Dept. N/A Reviewed by ( ) N/A 2 SCOPE OF SERVICES CITY OF OCOEE I &I REDUCTION FOR LIFT STATION AREAS 10 AND 12 April 10, 2012 I. INTRODUCTION The City of Ocoee's Lift Station 10 and 12 wastewater service areas are experiencing above normal infiltration and inflow (I &I) according to observations by City staff. While the City's treatment facilities can adequately treat the I &I flows, the high I &I peak flows during rainfall events can overload the collection system gravity pipes, force mains and lift stations. Given that significant wastewater collection infrastructure is at capacity during I &I events and that I &I reduction is beneficial to the City, the objective of this project is to reduce I &I in the City's highest priority area as recommended by City Staff. Desktop mapping tools and targeted field work will be performed to help isolate the I &I contributions. Field work including gravity pipe flow metering, smoke testing, CCTV inspection and visual manhole inspections as needed to accurately pinpoint I &I sources and direct capital funds cost effectively to the areas with the most need. Work orders will be generated and mapped to prioritize and schedule the City's remediation work efforts. This scope of service will provide services as listed below: 1. Data Collection and Analysis 2. Field Work 3. Field Generated Work Orders II. SCOPE OF SERVICES Reiss Engineering, Inc., (REI) will provide the services as listed below for the Lift Station 10 and 12 service areas inclusive of re- pumped sub -lift station areas: TASK 1: DATA COLLECTION AND ANAYLSIS REI will collect data and perform data analyses to facilitate I &I reduction for the Lift Station service area including Lift Station 10 service area as shown in Figure 1 and Lift Station 12 service area as shown in Figure 2. 1 REISS ENGINEERING ' t vv _ E ■ i *; i ff i 4'' S - 0 250 500 :" Feet 1 A , e r , y 1„,l' " LS45 Laa , 1 — F � . A ' t =` " LS10 '' '''' ' pow \ - ', , 14 4 s i + war a """"'■` ' 4: — 1 - . 9 3 - p . � a - " t *as ,,',,,,,,, , k4.'"1,:" — ' :lir . ,, „, ,, -riiiik ; ..... - it. 1„ ..41.% - fr' --,. , .4 %LT � � " t �., � �. » i '' i :4: It I . . s — > ',,, .. ' ' i, tri y� F , 1 I. ..: N i ": "33- . ." 4" a °A` - i ."' L44 4 -7 ' 1 ' *** a - '' , .., :, ', :: 1 .:, i I — . 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R CITY OF OCOEE LS 12 Service Area FIGURE 2 Path: C: \Users\wthaggen.REISSENV \Desktop \Ocoee Inflow and Infiltration.mxd , Task 1.1— Data Collection REI will: - Coordinate with the City to collect the necessary data and information needed to update relevant City wastewater collection mapping information, including technical data specifically related to the existing wastewater infrastructure (pipes, manholes, lift stations, lining /rehab status etc.), lift station run times, and other pertinent information. Task 1.2 — Data Analysis and I &I Maps REI will: - Analyze the collected, updated infrastructure data and identify the pump station areas of highest I &I concern. - Develop an I &I Prioritization Map based on revised City infrastructure information and the data analysis - Prepare I &I working field maps for Are Pad and set up Arc Pad for data entry Data Required: Pump run times for rainy season of June, July & August 2010 Pump run times for rainy season of June, July & August 2011 New lining of gravity mains, manholes and lift stations Latest GIS /CAD sewer mains Latest GIS /CAD manholes Deliverables: ♦ Data Request list ♦ Updated I &I Maps ♦ Study area specific- priority pipe segments TASK 2: FIELD WORK Engineering, management services and techniques will be provided by REI to ensure the Field Work Plan deploys resources efficiently to reduce the Lift Station I &I issues. Task 2.1 Field Work Coordination with City REI will: - Prepare and submit fieldwork schedule to City - Pre -field work meeting with City Utilities and Wastewater Collection personnel to discuss field work and identify relevant City - specific procedures or requirements. - Post field work meeting with City Utilities and Wastewater Collection personnel to discuss field results and outstanding I &I work orders. 4 C) REISS ENGINEERING Task 2.2 — Smoke Testing REI will perform the following smoke testing services based on a maximum gravity main length of 60,000 linear feet to be tested: - Smoke Testing Notification Hanger REI will develop, produce and place door hanger notifications for property owners assumed to be connected to the scoped smoke testing gravity mains. Notifications will include test date information, and other pertinent information relevant to the smoke testing process. - Smoke Testing Emergency Notification - REI will telephone and notify local City and emergency personnel on the morning of each smoke testing day to inform of the testing. Contacts will include police, fire, 911, City administrative and City utilities personnel. - Smoke Testing Execution - REI will execute smoke testing on the selected gravity mains up to a total length of 60,000 linear feet of gravity main. If smoke is found during the inspection it will be carefully GPS recorded and photographed. - Smoke Testing Work Order Generation - REI will use a handheld GPS computer during the fieldwork to identify and locate potential work order types and locations from the smoke testing. REI will produce the work orders in hard copy format to help the City prioritize remediation efforts. - Cleanout Cap Replacement — REI will replace cleanout caps on identified cleanouts during the smoke testing that have missing caps and serviceable threading. Those cleanouts requiring repair of the cleanout piping or thread fitting will be documented for later repair by the City. Task 2.3 — Flow Metering REI will: - Flow Meter Calibration — Flow metering equipment will be calibrated according to manufacturer recommendations. - Dry Condition Flow Metering - REI will inspect flow metering manholes and perform preliminary flow testing for each inflow pipe contained in up to 9 manholes during dry conditions. Flow testing will consist of opening one manhole and inserting an area /velocity flow sensor attached to a pipe insert ring fitting inside of the pipe. The flow would be recorded by an attached data recorder and downloaded to a laptop computer. Manholes selected during these conditions will be pre- selected based on lift station run times and strategic pipe intersection locations. - Wet Conditions Flow Metering - REI will administer flow testing for up to 18 manholes within approximately one hour of significant rain events. Flow testing will consist of opening one manhole and inserting an area /velocity flow sensor attached to a pipe insert ring fitting inside of the pipe. The flow would be recorded by an attached data recorder and downloaded to a laptop computer. 5 \ "" REISS ENGINEERING - Flow Metering Work Order Generation - REI will identify pipe segments and manholes that significantly contribute to I &I based on the flow metering results. REI will produce the work orders in hard copy format to help the City prioritize remediation efforts. Deliverables: ♦ Pre -Field Work Meeting with City ♦ Post -Field Work Meeting with City • Smoke Testing Execution for up to 60,000 linear feet of gravity sewer • Dry Flow Metering at 9 Manhole locations • Wet Flow Metering at 18 Manhole locations within approximately 1 hour of a significant local rainfall event. ♦ I &I generated Work Orders • Flow Metering generated Work Orders III. SCHEDULE The following schedule is estimated for the task set forth in this scope of services. Task & Deliverable Due Date Task 1 — Data Collection and Analysis 4 weeks from receipt of data Task 2 — Field Work —Smoke Testing 3 weeks from completion of Task 1 Task 2 — Field Work —Dry Flow Metering 5 weeks from completion of Task 1 3 weeks from occurrence of Task 2 — Field Work —Wet Flow Metering significant rainfall events and successful wet condition flow testing 6 REISS ENGINEERING IV. BUDGET ESTIMATE The City of Ocoee will compensate Reiss Engineering, Inc. for a time and materials fee not to exceed $45,190 as indicated below: Project Budget Task Total Cost Task 1 — Data Collection and Analysis 1.1 Data Collection $ 950 1.2 Data Analysis and I &I Maps $3,840 Task 2 — Field Work Engineering and Management 2.1 Field Work Coordination with City $3,890 2.2 Smoke Testing (Mobilization) $2,900 2.2 Smoke Testing (Field work at $0.24 per foot gravity $14,400 main tested) 2.3 Flow Metering (Mobilization) $3,010 2.3 Flow Metering (Field work at $600 per manhole $16,200 tested) Project Total: $45,190 V. RESPONSIBILITY The CITY will be responsible for the following: • Provide data, technical review, and participation in review meetings. • Functional manhole covers and access to manholes and lift station wetwells. • Repairs to the sewer system identified including cleanout repairs that require more than cap replacement. VI. SERVICES NOT INCLUDED The following services are not included and could be included via addendum: • Cleanouts requiring new piping or extensive repairs. • Manhole rehabilitation and repairs. 7 REISS ENGINEERING