CENTER POINT WASTEWATER COLLECTION SYSTEM

CLIENT: TETRA TECH

PROJECT SUMMARY

Kerr County is providing their residents with a sanitary sewer collection system. This project consists of approximately 178,000 linear feet of sanitary sewer force mains and gravity type lines of varying sizes. The system is interconnected with eleven lift stations throughout and spans the entire Comfort and Center Point incorporated areas plus the areas in between. This project is federally funded, so budgeting is a key concern for the consultant.


We drove each section of the sanitary sewer lines and took pictures to identify all of the miscellaneous scope items that wouldn’t be shown on the plans, such as driveway repairs, roadway repairs, fencing repairs, etc. Due to the large quantities of pipeline over 18 miles, those small items equate to a large portion of the construction budget.


During our site evaluation, we identified the location of all of the lift stations. Once discussed with the consultant, we realized that there was only single-phase power available to each site, but 3-phase power would be required. The energy provider for the area was consulted to determine the cost of adding 3-phase power - a cost that was not included in the original construction budget.


Due to the large quantity of work involved in this project, another of our objectives was to phase it or break up the scope into equal packages so we could invite more contractors to bid the project. Since the project is mainly pipeline installation, we felt that would limit the number of qualified bidders. If we broke up the scope into multiple packages and bid the lift stations out as a separate package, we would increase the quality of work; line contractors do not want to build lift stations and lift station/facility contractors don’t want to build pipelines. We would also increase competitiveness amongst all bidders, which would reduce the cost of construction by a few percentage points. The schedule for this project was also important because of funding and the length of time required to construct 18 miles of sanitary sewer system.


The client was concerned about starting the warranty on the lift stations before the pipeline was complete and having the lift stations under warranty with nothing running through them, so we had to phase the project in such a way that we could start the warranty for the majority of the work within a small window. We also had to deal with TxDOT right-of-way issues related to aerial crossing options or directional drilling alternatives at each crossing within TxDOT right-of-way. After discussions and cost comparisons with the consultant, it was determined that directional drilling would be done where feasible based on TxDOT recommendations. Our team provided cost estimates for numerous scenarios so we would have a plan in place for whichever direction was chosen. We also made numerous recommendations for alternative routing options in order to eliminate small runs of pipelines that seemed unnecessary.


We are currently awaiting the funding process to continue our cost estimating efforts and complete this project.