SANITARY SEWERS AND PUMP STATIONS

East Point Relief Sewer and South Camp Hapeville Outfall Replacement Sewers, City of Atlanta, Georgia

These US EPA Consent Decree projects consist of the design of 15,000 lineal feet of sewer ranging in size from 36 to 42 inches and a second 18-inch sewer of approximately 560 feet in length. Specific activities included: project management, site investigation, route analysis, public involvement, easement acquisition, permits and project approvals from regulatory agencies, surveying, geotechnical investigation, cost estimating and scheduling, field inspection, QA/QC reviews, prepared technical memoranda, developed complete pipeline alignment, prepared all plan & profile sheets, other related construction plans, and specifications. Sewer construction methods were evaluated, including open cut and trenchless technologies such as pipe-bursting, micro-tunneling and jack & bore.

Greensferry Sewer Separation, City of Atlanta, Georgia

The City of Atlanta was required to separate a portion of its combined sewer system to comply with a US EPA Consent Decree.  New pipelines were constructed to convey the sanitary sewage and the existing pipelines were used to transport stormwater. The project was implemented to mitigate sewer overflows in the West End and Atlanta University Center communities. The project was completed ahead of the US EPA mandated consent decree completion date. Approximately 57,000 feet of new sanitary sewer and 381 manholes were constructed at a cost of $79.6 million. Reparations were made to streets, curbs, landscaping and 48,000 feet of water mains were replaced. Cardozo Engineering staff provided construction management and inspection services on this project.

South River SSO Capacity Relief Sewer Replacement Projects, City of Atlanta, Georgia

This project will serve to mitigate sanitary sewer overflows in the South River Basin.  Approximately 23,000 lineal feet of sewer segments will be upsized and replaced with new pipe ranging in size from 15 inches to 42 inches in diameter. Specific activities include:

• Field Investigation and route analysis
• Engineering design – plan & profile sheets
• Surveying
• Public outreach and information program
• Obtaining permits and project approvals from regulatory agencies
• Verifying and acquiring easements
• Conducting geotechnical investigations
• Locating underground utilities
• Providing Bid Services
• Construction Cost Estimating

South River Tunnel Pump Station, City of Atlanta, Georgia

The new 30 mgd South River Tunnel Pump Station will be constructed at the existing South River Water Reclamation Center. The design will allow for a total ultimate installation of 4 submersible pumps, each rated at 15 MGD.  Three (3) pumps will be initially installed (2 plus 1 standby). Cardozo Engineering’s tasks included construction cost estimating and drafting.

20 MGD Intrenchment Creek Tunnel Pump Station, City of Atlanta, Georgia

The City of Atlanta’s 20 mgd tunnel pump station was experiencing significant operation and maintenance problems and disruptions in service due to a buildup of solids in the tunnel. To mitigate these problems, Cardozo Engineering developed a plan to replace the existing equipment, piping and controls, reshape the wet well, remove solids from the tunnel and change the operating parameters of the pumping station. The existing 110 foot deep wet well was gutted and equipped with three new 10-mgd submersible pumps, two new 2-mgd submersible dewatering/grit pumps, an overhead lifting mechanism, flow monitors and controls.  Discharge piping included a total of 450 lineal feet of 20-inch force main and 140 lineal feet of 8 inch force main. Changes in the wet well configuration and controls were made to reduce grit accumulation and improve pump station efficiency, and the solids within the tunnel were removed utilizing a backhoe and sewer gator.

Tasks included:
• Project Coordination, planning, coordination of multi-discipline team and cost estimating
• Preliminary and final design of pump station, piping and related equipment and preparation of plans and specifications.
• Construction Management: site inspections, show drawing reviews, preparation of responses to Requests for Information (RFIs), review of claim and change order submittals, review of construction contract schedules and schedule of values, and review of as-built drawings.

Miami-Dade County’s Comprehensive Wastewater Master Plan and Peak Flow Management Study, Miami, Florida

Under a US EPA Consent Decree, the Miami-Dade Water and Sewer Department was tasked with evaluating the capacity and operation of nearly 1,000 pump stations, 500 miles of force main and 2,500 miles of gravity sewer in order to prepare a peak flow study and master plan for Miami-Dade County. This project included the utilization of a dynamic model, evaluation of groundwater and rainfall data, and analysis of SCADA data. Recommended upgrades to the system to minimize overflows, maximize system capacity and to comply with a 2 year, 24 hour design storm include upgrades to pump station capacity, strategic RDII reduction in private and public laterals, relief sewers, treatment plant improvements and operational changes.

Tasks included:

• Determination of the flow for the Miami-Dade County sewer collection system pump stations. This is achieved by analyzing the data provided by the current SCADA system.
• Development of Daily Hydrographs for all pump stations for the period of 2003 -2006, illustrating the influence of rainfall and ground-water level. A total of 816 hydrographs were developed using the nearest rain and ground-water level gauges, to establish their influence on the pump station flows. These hydrographs provided the Annual Average Daily Flow (AADF) for each basin.
• Development of Hourly Hydrographs for the pump stations affected by 2-year storm events since 2003, depicting the rainfall and ground-water level influence. More than 3,000 hydrographs were analyzed to select the appropriate graph, and to determine peak flow factors and dampening factors for each rain event. A study of each peak flow was performed for a period from 12 hours prior the peak flow and 36 hours after the peak flow time, to examine different combinations of peaking factors.
• Determination of the nightly flow and the infiltration rate during the dry season for each basin.
• Regulatory compliance review and regulatory and utility coordination

Miami-Dade County’s Pump Station Improvement Program and Consent Decree/Settlement Agreement Program, Miami, Florida

The Miami-Dade Water and Sewer Department utilized a Management Team to manage its $1 billion construction program to improve its wastewater system. Program improvements included the rehabilitation of over 700 pump stations and force main projects, evaluation and rehabilitation of over 13 million feet of gravity sewers and a 77.5-mgd expansion to its three wastewater treatment plants.

Cardozo Engineering (CE) staff, while employed with other firms, were responsible for the following for the overall Consent Decree/Settlement Agreement Program: developing and managing the master design and construction schedule, preparing construction contract documents, evaluating design-build bids, evaluating proposals and authorizations, processing invoices, providing cost engineering, managing a change control system and reporting to MDWASD, DERM, and US EPA. Significant interest savings in capital budgeting and financing were realized by rendering realistic projections for program cost, funding requirements, and cost modeling and the overall program cost was reduced from $1 million to $930 million.

On the Pump Station Improvement Program, CE staff developed a work breakdown structure and base-line schedules, conducted claims analysis and variance analysis, recommended corrective actions, and provided cost estimating, control and modeling, progress monitoring, and reporting including cash flows, S-curves, schedules, and exception reports. They also provided development, coordination, and control of database management information system applications, applied Primavera to successfully develop base-line schedules and to monitor and track project activities, developed cost trend analysis, monthly cash flow forecasts and fiscal year projections.

Other program responsibilities performed by CE staff included program planning, funding assistance, regulatory compliance and overall management of functions such as preliminary design, systems engineering, cost estimating/control, scheduling, coordination with design consultants, developers, regulatory agencies, Public Works, DERM, utilities and other ongoing projects, technical reporting, document control, community outreach, public information, coordination of minority consultants and meeting minority goals, and a small contractor development program.

Sanitary Sewer Evaluation, Design and Construction Management, City of Atlanta, Georgia

The City of Atlanta implemented a comprehensive Sanitary Sewer Evaluation Survey (SSES) and Rehabilitation Program as part of its $3.9 billion Clean Water Atlanta Program to reduce Infiltration/Inflow (I&/) and eliminate sewage overflows. This program includes the evaluation, replacement and/or rehabilitation of 2,200 miles of sanitary sewers and appurtenances.  Cardozo Engineering staff manage the SSES Engineering Program for the City, determine repair/rehab methods, prepare technical specifications and bid contract documents, work with the Procurement Department to fast-track the award of projects, prepare contract documents and technical specifications, and provide construction management of the rehabilitation program.  Construction improvements include: cured in place pipe liner, cementitious liner, internal and external point repairs, sealing and grouting, raising manholes, cleaning and root removal. Replacement techniques in use include pipe bursting, open cut trenching, and horizontal directional drilling.

Miami-Dade County’s Comprehensive Lateral Investigation Program (CLIP) to Reduce Peak Flows, Miami, Florida

The Miami-Dade Water and Sewer Department (MDWASD) previously completed a comprehensive infiltration/inflow (I/I) reduction program to detect and repair groundwater and wet weather flow sources in the County wastewater collection system. The I/I Program was successful in reducing the daily flow to the wastewater treatment plant, but still the rainfall dependent infiltration/inflow (RDII) flows remained high. The Department then directed its focus to the evaluation of the public and private sewer laterals, since the lateral sewers from the house to the collection sewer in the street were not included in the original I/I Program. The subsequent Comprehensive Lateral Investigation Program (CLIP) was implemented to further study the impact of these sewers on peak flows. The first phase of the CLIP was to select a sample of approximately thirty sewer collection basins based on high RDII levels, size of the basin, age, zoning and location throughout Miami-Dade County, and to determine the condition of the laterals. Hydrographs were developed for each of the pump station basins for various rain events, before and after the repairs of lateral defects were completed. The results of the study will be utilized to further target and reduce RDII emanating from select pump station basins throughout the County in order to reduce peak flows. This study was approved by Region 4 US EPA and will serve as a model for other municipalities throughout the United States who are experiencing rainfall dependent Infiltration/Inflow problems that contribute to excessive peak flow during wet weather events.
 
This study included: 
• Project planning, preparation of construction documents and administration of construction contracts.
• Project scheduling.
• Investigation of the condition of sewer laterals, sewer lateral testing and inspection.
• Repair of sanitary sewers.
• Evaluation of infiltration and inflow, pump station and sewer system flows, and the evaluation of rainfall and groundwater data as it relates to the sewage flows and pump station performance.
• Construction supervision, preparation of summary reports and project recommendations.
• Preparation of a comprehensive study.

This project also included the implementation of a successful public information/outreach program, which included:
• Preparing and mailing out 9,200 letters to property owners requesting permission to enter private property. Letters were prepared in three languages (English, Spanish and Creole).
• Coordinating mailing letters to property owners.
• Preparing door hangers distributed prior to working in area.
• Preparing 250 letters to property owners informing them of lateral pipeline defects.
• Establishing a customer relations call center to promptly respond to property owners’ concerns.
• Developing a database of the properties in the study area to include property owner data, folio numbers, property addresses and mailing addresses.
• Developing a Customer Service database to track calls from property owners, requests for information, and program participation responses.  Responses were received from 71% of property owners and over 96% of these responders voluntarily elected to participate in MDWASD’s program. This study was approved by Region 4 US EPA and will serve as a model for other municipalities throughout the United States who are experiencing rainfall dependent Infiltration/Inflow problems that contribute to excessive peak flow during wet weather events.  

Miami-Dade Seaport Condition Assessment of 8-inch Force Main, Miami, Florida

The Port of Miami utilizes a single 8” diameter ductile iron sanitary force main constructed in 1964 to convey sewage from the Port to the wastewater treatment plant. Three lift stations convey sewage through the force main from the Port, beneath Biscayne Bay and onwards to the Miami Mainland. Due to the current age of the pipeline, the Port was concerned about pipeline integrity due to the possible detrimental effects associated with soil corrosion and internal corrosion due to the presence of Hydrogen Sulfide, hydraulic surges, and tidal effects (including storms).  Since the pipeline extends under Biscayne Bay, which is a protected pristine marine estuary, the Port was concerned about the potential for sewage releases into the Bay and subsequent environmental impacts. The force main is also the only means for removing sanitary waste from the Port, and any interruption in this line would be detrimental to not only the Port but its customers, which primarily includes the cruise ship industry.