Flush with Success
Cass Township in Schuylkill County (an area of “rural Pennsylvania”) currently has no public sewer system. The township’s topography varies from very flat in the valley areas to very steep terrain in other areas. The geology is not conducive for individual on-lot septic tanks. In the past several years, PADEP has been concentrating its efforts into mandating these municipalities to address their sewage needs.
These problems are not unique to Cass Township. Such sewer problems are common throughout Pennsylvania, West Virginia and other states. In order to address the state’s sewer issues, the Pennsylvania Department of Environmental Protection instituted the Pennsylvania Sewage Facilities Act 537 in 1966. The act establishes municipal sewage requirements and makes municipalities responsible for converting malfunctioning on-lot systems, overburdened treatment plants and sewer lines in order to protect the health, safety and welfare of their citizens.
In 1995, Cass Township supervisors hired Alfred Benesch & Company of Chicago, Ill. with offices in Pottsville, Pa., to assist them in meeting these requirements. Benesch developed the Cass Township Act 537 Sewage Facilities Plan, a comprehensive study for providing an adequate sewage system, which the state approved in 1999. The following year, Cass Township obtained design funding from the Pennsylvania Infrastructure Investment Authority (PENNVEST) to implement the system.
As a result, Cass Township formed a Joint Sewer Authority with neighboring Branch Township. Both townships will soon complete the construction of a sewer collection system with pump stations. They will discharge their sewage to a 450,000-gallon per day wastewater treatment plant in the village of Llewellyn, located in Branch Township. Once the project is constructed, property values are expected to increase because of the availability of public sewage. Environmentally, the area will be a cleaner and safer place in which to live. Residents will be healthier due to the reduced risk of sewage contamination.
Planning For a Cleaner FutureCass Township retained Benesch for the design work. The Cass Township portion of the project costs approximately $5.5 million for design and construction of:
- Three pump stations
- 13,500 feet of sewer laterals
- 75,000 feet of main sewer pipe
- 8,100 feet of force main pipe
- 28,000 feet of low pressure sewer pipe
- 180 grinder pumps
The design process began in October of 2000. The construction phase is scheduled to last 18 months and will begin early in 2002. Benesch chose MicroStation, InRoads Survey and InRoads Storm & Sanitary (Bentley Systems Inc., Exton, Pa.) to assist in the design of the Cass Township project.
“We were already using InRoads, Survey and Site products, so Storm & Sanitary seemed the natural choice,” says David Crispell, project engineer at Benesch. “This project was a good one for us to begin using InRoads Storm & Sanitary since it was such a large project. We felt the return on the investment of time in learning how to use the software was worth it.”
Although some at the company were already familiar with Bentley software, Crispell had never used MicroStation or any of the InRoads products before. He quickly became productive in his work on the project, taking advantage of training modules available on the software and attending an on-site training class.
“I spent about two weeks getting familiar with both MicroStation and InRoads Storm & Sanitary,” Crispell says. “The key to any of these software products is to use it once you’ve been trained on it.”
Improving the Design ProcessBenesch used both aerial photography from Air Survey, Dulles, Va., and its own GPS data to create the digital terrain model. Floor elevation was also needed at the low-lying homes to aid in the design. Benesch then performed some ground surveys in the dense areas and merged the data together to form a more accurate topography plan and digital terrain model. The survey data was processed using InRoads Survey, which allowed plotting with the correct standards symbology for the project, which saved drafting time.
“InRoads Survey is the best software on the market,” says Robert Doyne, software technician at Benesch. “I can handle my data from beginning to end, from importing the SDR field survey data, to creating digital terrain models and coordinate geometry. I can then display the data to meet the required standards once the base mapping and preliminary design are complete.
“I have tried various survey plotting software over the years. All the products we tried involved exporting one file type to another. This is not expected and wastes too much time. The software that Benesch uses is client-driven. MicroStation and InRoads are in those formats.”
Merging Field Survey Data with Aerial MappingThe variations in topography presented some challenges in design. “Due to the fact that it is quite hilly, it was very difficult finding routes and rights of way,” Crispell says. “We went through many iterations, moving pipes around, to find the best placement. There was a myriad of existing underground utilities to identify and place into the drawing. InRoads Storm & Sanitary helped me see these utilities in the profiles. Coupled with the ability to graphically move the sewer pipes in the profile, I was able to easily make adjustments to avoid the utilities.
“We were unable to provide gravity sewer lines for everyone due to the topography. I had to use low-pressure sewer lines instead to accommodate the low-lying houses. InRoads Storm & Sanitary’s network analysis helped me to size the pipes with all of the incoming low-pressure flows.”
Benesch used the Plan and Profile generator to develop plans and create profiles, by the same techniques previously used by hand. “InRoads Storm & Sanitary took one-fifth the time it had taken us to create plans and profiles manually in the past,” Doyne says.
Benesch also used InRoads Storm & Sanitary to perform the hydraulic analysis on the entire collection system. Formerly done by hand in spreadsheets, they now generate the data automatically, and then several engineers perform spot checks. This saves time on iterative changes and ensures data accuracy.
“With Storm & Sanitary, I can easily display the engineers’ designs on my plans and know that I have their latest revisions,” Doyne says. “It streamlines the whole process and saves us so much time compared to other methods. You basically have the whole project readily available for display or design.”
InRoads Storm & Sanitary’s reporting capabilities helped Benesch analyze the design. The software also aided their calculation of material takeoffs for cost estimating.
Benesch plans to buy more licenses of Storm & Sanitary as a result of its performance and time-saving tools.