- Gas Distribution Main Renewal Program
An upper Midwest gas company is performing a main renewal program (MRP) to improve its gas distribution system by bolstering system reliability and safety through distribution infrastructure upgrades. This multiyear program focuses on removing and replacing existing legacy cast iron and unprotected steel pipelines with medium density polyethylene (MDPE) pipe, typically at a higher operating pressure. The approximate 3,800 miles of legacy cast iron and unprotected steel distribution gas main is expected to be renewed at a pace of about 150 to 250 miles of main per year. The initiative also includes relocating approximately 280,000 inside meters to an outside location. The MRP has annual targets for both legacy main renewal and inside meter relocation.
Our team performed the engineering design, project management and permit acquisition for a 20-mile urban grid. The scope was to replace the existing 2# and 10# cast iron system with 60# MDPE and HDPE pipe. The proposed main size ranged from 2- to 12-inch plastic. We partnered with a local MBE firm to perform the survey needed for the grid. LiDAR survey collected physical information, and dig tickets were submitted for utility as-builts within the grid. The design team analyzed the system to identify one-way feeds and bypass needs and utilized the client’s programs for functions and additional services throughout the project life cycle. ESRI (ArcGIS) was used to obtain the existing gas and electric service mapping. Maximo was used to create and maintain both main and service work orders, as well as a project material lists.
We incorporated the survey base maps, along with the information collected from a field investigation, to develop construction level drawings that provide a feasible design for the 20-mile grid. The drawings were separated by street (total of 56 drawings) and required multiple reviews throughout the 30%, 60% and 90% submittals. Quality control processes were implemented to oversee that all drawings were free of errors and adhere to the clients defined quality standards. We applied for and obtained municipal and state permits, as well as a title search, easement sketch and a legal easement description.
We were subsequently assigned 18 Risk Ranks projects (totaling approximately 8 miles). These projects include a series of streets consisting of smaller “at risk” segments of distribution main renewal at the existing operating pressure. Services will be renewed/tied over and inside meters relocated.
- Topographic, boundary and easement surveys
- Engineering construction drawings and package submittal
- Permit identification, application and obtaining, including municipal, county road commission, state department of transportation, environmental agencies, railroad, historical associations, mechanical building, soil erosion and sedimentation control, Army Corps of Engineers, county drain commissions and traffic control permits
- Project management
- Tracking of design activities by street
- Construction engineering support
- Record research and organization
- Preparing work orders as described within specific contracts and/or purchase orders