Pipeline Analysis, LLC is specially suited for the evaluation of wastewater collection systems as this is our only field of endeavor. All of our efforts are in maximizing testing results and preparing sound analysis recommendations. Pipeline Analysis, LLC (PA) has established a core group of processes, equipment and field testing software designed to diagnose, maintain and support the valuable assets that are our clients' wastewater systems. Our refinement of field testing equipment and data processing procedures increases field productivity thus reducing project costs.
A goal of the collection system manager is to develop long-term solutions to infiltration/inflow (I/I) and sanitary sewer overflows (SSO's). The first step in achieving this goal is to establish the magnitude and location of the problem. Temporary flow monitoring will isolate and quantify the dry weather groundwater infiltration that enters the collection system through poor pipe joints, poor service connections and cracked/broken pipe. In addition, flow meters will isolate the areas of the collection system that contribute to excessive rainfall dependent infiltration/inflow (RDII) that enters through poor fitting manhole castings, vented manhole covers in ponding areas, holes in pipes, open or defective cleanouts, yard drains, storm sewer cross connections, etc. Our experience on performing hundreds of such evaluations show that approximately 80% of the RDII will be isolated on approximately 50% of the collection system. Knowing which 50% to target by priority will minimize overall collection system rehabilitation cost and will provide a structured phased plan. Keep in mind that chronic SSO's during wet weather indicate inadequate capacity at that location, but the rain water that entered the system to cause the SSO may originate miles upstream. Temporary flow monitoring will isolate the areas of highest priority and a systematic phased plan can be developed to then locate and prioritize repairs.
With a design life of 75 to 100 years, many collection systems have reached its design life. Infiltration/inflow is a symptom of an aging collection system. As engineers working on these project we must identify specifically where the deterioration is occurring and develop a plan to locate and repair these City assets. Municipalities can not afford to wait for system failure and replace the collection system. The least cost strategy will be to locate system defects early while trenchless repair methods can be used.
Timing of field work is critical in evaluating collection systems. Flow monitoring is the first phase and it is critical that the meters be installed at the optimum time to reduce project costs. In addition, it is just as important to perform smoke testing during the dry seasons to maximize the testing results. Smoke testing results are dependent on dry soil conditions to maximize the effectiveness of the testing. Pipeline Analysis owns all the flow meters, rain gauges, testing equipment and diagnostic equipment for evaluating collection systems.
Pipeline Analysis has extensive recent experience working with state regulatory agencies to develop reasonable programs that meet the needs of all parties involved. Analyzing the data gathered in the field, the necessary "engineering evidence" is prepared that supports the overall plan and presents the regulators with the information to justify the plan or any requested revisions to the original plan. Pipeline Analysis only performs sanitary sewer evaluations and over 90% of our projects involve regulatory compliance issues. Assisting the utiltiy in achieving regulatory compliance may include recommendations for addressing repairs on private service lines, distinguishing chronic SSO's from periodic stoppages, impact of grease, current fats, oil and grease (FOG) ordinance update, documentation of customer stoppages, etc.
Educating the customer on the vast investment sitting "out of sight, out of mind" and the need to repair these assets can be facilitated throughout the various phases of the project. Effectively presenting the findings in easy to understand graphics and language will help the customers acknowledge the need for repairs and the costs associated with it. Benchmarking with other similar cities can show the city leaders and public that the problems being faced are not unique to their system. Using the team's technical expertise in trenchless rehabilitation, the impact to residents during construction can be minimized and least cost solutions recommended.
To minimize project costs for our clients, Pipeline Analysis has invested in all the necessary inventory of flow meters, rain gauges, gas detectors, smoke blowers, CCTV inspection truck, GPS, ArcGIS, digital databases, pen based data entry system, etc. There is no need to rent equipment and pass that expense on to our clients. In addition, since collection system evaluation is our only field of endeavor, all our resources are targeted for similar projects. Our staff has extensive experience in the most cost-effective methods of data gathering and analysis, prioritizing future work, recommending least cost repair alternatives, and minimizing the impact to customers.
Collection system renewal is a continual process of finding system defects, prioritizing them and fixing them. The "find-it" portion of the program is commonly referred to as a sewer system evaluation survey (SSES). The goal for the collection system manager may be to inspect the collection system on a 10-year cycle. (Note that critical sewers or those assets in flood prone areas may be on an annual cycle of inspection.) A ten year cycle will require inspecting/testing 10% of the collection system annually. The results of the inspection will generate repairs to manholes and mainline sewers. Private sector defects will also be identified requiring enforcement of local codes. Budgeting funds to find and fix system defects is the least cost solution to extend the life of the collection system another 75 to 100 years. Waiting for pipeline or manhole failure will require replacement of the assets which is the most expensive alternative (by several factors).
Rehabilitation methods available to extend the life of collection system assets (renewal of assets) include trenchless technologies that minimize the impact to customers. Manhole rehabilitation may include lining, sealing, installing water tight ring and covers, raising buried manholes to grade, replacing vented covers, etc. Mainline sewer rehabilitation may include cured-in-place pipe (CIPP), slip lining and upsizing or pipe replacement by pipe bursting. These "fix-it" technologies are expanding to service laterals which must be addressed by collection system managers.
For example, the capacity analysis performed in the master plan will impact sewer system renewal. Knowing when a particular pipeline will require upsizing will impact the decision to rehabilitate the pipe. It may be more cost effective to defer rehabilitation (yet maintain the pipe) and replace the pipe as part of the capital improvement plan (CIP). Also, the least cost renewal plan may require deferring some rehabilitation until sufficient quantities are identified to reduce unit repair costs. Utilization of term contracts for collection system renewal is gaining favor as it speeds up the process of rehabilitation and fixes unit prices, thus keeping projects within annual budgets.
The infiltration/inflow analysis (I/I Analysis) may be included in other sewer system projects(such as SSES, Master Plan, Hydraulic Modeling, etc) but is usually the first step in evaluating the collection system. Installation of wastewater flow meters and rain gauges establishes the "heartbeat" of the collection system. Dry weather flows provide baseline data and capacity being utilized during dry weather in addition to evaluating groundwater infiltration that may enter the system. Rainfall creates the stress test and measures the leakiness of mainline pipes, manholes and private sector service lines. Using GIS rainfall distribution techniques, including NEXRAD radar images, each rainfall event can be analyzed to determine its impact on the collection system hydraulics. By establishing the relationships between dry and wet weather flows, the collection system can be effectively evaluated and areas prioritized based on capacity being exceeded, observed bottlenecks, volume of inflow, etc. The data from an I/I Analysis may be used to calibrate collection systemhydraulic models, project design storm flows, determine the current level of protection from SSO's, establish customer city contributions, etc. Of prime importance will be establishing the priority ranking of each metered service area based on infiltration/inflow. The ranking should be used to initiate a phased evaluation to locate the sources of extraneous flows and establish least cost repair methods and costs.
Many municipalities have moved forward with CMOM (Capacity assurance, Management, Operation and Maintenance) Self-Audits to gauge where their SSO program currently is and where it needs to be to optimize system performance. The audit provides an independent review of existing procedures, program weaknesses and recommends improvements with implementation schedules and estimated costs. Pipeline Analysis staff has performed CMOM Self-audits for the following communities:
Using the Region IV EPA guidance documents, the self audit will address areas such as engineering design practices, mapping, equipment and system maintenance, ordinance review, FOG program, sewer testing, SSO plan, safety program, rehabilitation standards, construction inspection, budget adequacy, staffing, sustainability, human resources, etc. The CMOM self audit performed by Pipeline Analysis, LLC is a tool for the collection system manager to gauge where improvements are needed by priority along with estimated costs and implementation schedule.
Temporary flow monitoring is used to determine the hydraulic conditions of sanitary sewers under various conditions and prioritize area for testing and evaluation efforts. Temporary flow monitoring can be used to determine:
The staff of Pipeline Analysis, LLC have experience with all the major equipment manufacturers. In addition, we have worked in pipelines from 6" to 108". Pipeline Analysis, LLC owns 80 state area/velocity flow meters and 18 continuous recording tipping bucket rainfall gauges.
CCTV inspection -Internal TV inspection (using Pipeline Assessment Certification Program-PACP codes) is used to determine the nature of specific defects located during smoke testing and physical inspection. Using high definition miniature color cameras, the TV operator inspects the interior of sewer pipes looking for defects and the condition of the pipeline. Line segments are recommended for inspection when smoke testing indicates main line defects, chronic maintenance problems or observed hydraulic restrictions. Possible cross-connections with storm sewers are evaluated and least cost rehabilitation methods are determined by analysis of the CCTV results. Pipeline Analysis staff are PACP certified and we have a certified PACP trainer on staff. Digital video and databases are provided on DVD or portable hard dirve.
Chronic sanitary sewer overflows occur in the same general location and may be caused by structural defects, inadequate capacity, excessive infiltration/inflow, grease, roots, etc. Understanding the cause for the overflow will establish repair alternatives and costs. Tools that may be used to evaluate the SSO may include flow monitoring, manhole inspection and CCTV inspection. Using field observations collected will provide the data necessary to establish an abatement plan and schedule.