One of the main objectives of Hilltown Township Water & Sewer Authority (HTWSA) in the design of Highland Park Wastewater Treatment Facility was integration of the treatment facility into its surrounding community. Adequate facilities for wastewater treatment are necessary components of all growing communities, however traditionally no one wants a wastewater treatment plant in their back yard.
Planning and Design Phase
During the planning and design phases of the project, many neighboring businesses and residents voiced concerns about the proposed project. HTWSA addressed all community concerns including neighboring businesses, a community action committee as well as a neighboring residential retirement community. Some of the concerns were aesthetic; others feared off-site odors, while others had environmental related concerns.
In order to blend the facility into the community and rural surroundings, HTWSA wanted Highland Park Wastewater Treatment Facility to mimic the appearance of a Bucks County Farm. HTWSA chose Castle Valley Consultants, an Environmental and Civil Engineering firm specializing in innovative wastewater treatment facilities. Castle Valley Consultants along with a team of Design Professionals, spent over two years in the design phases assuring the wastewater treatment facility would address the current and future wastewater needs of the community as well as all other community concerns ranging from aesthetic to noise and odor control.
To address aesthetic concerns, a local architecture firm, George Donovan & Associates, who specializing in historic preservation and historic replication was commissioned to design buildings to house almost all of the mechanical systems of the facility. Each building’s façade resembled buildings typically found on local farms.
In the early phases of design, an environmental inventory was conducted on the five-acre tract to identify natural resources such as soils, geology, hydrologic conditions and vegetative plant communities. Plant communities typical of Pennsylvania’s Ridge and Valley Physiographic province were found including: wetlands, over 2 acres of lowland and upland meadows, an existing hedgerow of lowland woodland species and an overgrown stand of white pines, presumably relics of a white pine nursery. All natural resources were evaluated to help identify the most environmentally appropriate areas to locate the facilities structures. As part of this evaluation, the existing vegetation was examined based on environmental sensitivity and a hierarchy was established to limit disturbance in these areas. The hierarchy favored natural plant communities giving wetlands the highest level of protection, followed by lowland & upland meadows, lowland hedgerow and finally the stand of white pines.
Due to the complexity of underground piping and structures, a large open area was needed for the proposed site facilities. Based on the established hierarchy of plant communities and other environmental factors, the proposed facilities structures were located within the stand of pines leaving a buffer near the pines perimeter. The design of the facility included detailed Landscape Plans by Environmental Landscape Designer Christian Birch of Castle Valley Consultants.
The objectives to the Environmental Landscape Plan were:
- Limit the amount of disturbance in environmentally sensitive areas;
- Preservation of existing wetlands;
- Restoration of lowland and upland meadow communities in an attempt to restore the order of plant succession prior to construction;
- Implementation of Best Management Practices (BMP’s) for Stormwater Management;
- Limit the amount of turf grass to reduce site maintenance;
- Coordination of grading and layout of wastewater treatment facility with the Environmental Landscape Plan;
- Optimize the use of native vegetation;
- Use naturalized buffer plantings at the site’s perimeter mimicking the character of a rural farm; and
- Education of all involved with the project before, during and after construction.
Prior to construction, a meeting was held on-site and detailed instructions were given to the contractors including tree protection and staging techniques. Contractors were not allowed to proceed with construction until proper erosion and sedimentation control and tree protection devices were in place. Contractors were also given plans that defined allowable areas for staging and storage of materials.
During and After Construction
During construction, Christian Birch was on-site to observe that all landscape plans and specifications were followed as well as address any questions from the contractors.
After construction, a detailed Landscape Maintenance Plan was written and adopted by HTWSA. The Authority has begun in-house educational programs for staff that includes tree care, landscape maintenance and meadow management. The Highland Park Wastewater Treatment Facility has become a model of innovative state of the art wastewater facility design. The site has ongoing tours for other municipal officials who are looking for site design alternatives for wastewater facilities.
Recognition / Awards
Official Accommodation from Pennsylvania Legislature
2003 – 2004
Project Participants and Roles
Civil / Site Engineer / Landscape Architecture
Castle Valley Consultants, Inc
George Donovan & Associates
Long, Tann and D’Onofrio