Black Rock Sanctuary

Challenge

Because the site had been a decanting basin, there was concern about soil contamination, particularly heavy metals, which could lead to biomagnification of these toxins in the food chain since the intention was to serve as breeding and nesting habitat for migratory birds. The new sanctuary would also have to manage stormwater from the neighborhood located across the street, since runoff ran directly from the lawns of the subdivisions into the pond on site, causing extreme algae buildup from excessive fertilizer use. Another major challenge was the eradication of Ailanthus and other invasive species on the site to establish new, native vegetation. Keeping invasives under control would be an ongoing maintenance challenge.

Solution

To prepare the site for wildlife habitat, over 12,000 cubic yards of coal silt were removed. Soil, water, and fish tissue testing determined that heavy metals were not a concern in this system. To manage the stormwater runoff from the adjacent neighborhood, a series of bioinfiltration cells were designed to clean the water and recycle it back into the natural system. These cells allow water to infiltrate into the ground, while plants biologically degrade the pollutants. The Ailanthus and other invasive woody species were ground up, mulched, aged, and reused on site to provide organic matter that supports new plant growth. The sanctuary is closely monitored for incoming invasive species such as phragmites and Japanese knotweed and periodically undergoes eradication methods such as cutting and spraying.

• 47 acres of new wetlands were created, including 5.0 acres of emergent herbaceous wetland, 1.3 acres of emergent wetland, 1.7 acres of scrub/shrub wetland, and 3.5 acres of forested wetland, none of which were present on the existing site.
• 10 acres of new upland meadow were created to provide habitat for ground nesting birds, covering over 8% of the total site area.
• The site contains 1.1 acres of vernal pools that support tree/wood frog, salamander, and turtle habitats.
• A biofilter captures, infiltrates, and biologically degrades pollutants from the adjacent neighborhood’s stormwater runoff. The three cells are heavily planted with species such as blue vervain, fox sedge, swamp milkweed, blue indigo, and black-eyed susan.
• A rain garden, containing plant species such as river oats, little bluestem, Virginia wildrye, fox sedge, and purple coneflower is located in the center of the parking lot to capture stomwater runoff. Vegetated swales aerate and filter water from the parking lot to the wetland.
• A butterfly garden with plant species such as false indigo, joe-pye weed, purple coneflower, wrinkleleaf goldenrod, and beebalm provides habitat for pollinators.
• A 0.75-mile ADA-accessible interpretive trail includes nine educational exhibits that describe wetland environments, their importance and their benefits in a fun, interactive way.
• All plant materials are indigenous to the region and typical of similar sites in the area.
• Branch clumps were kept for use as refuges for fish fry in existing deep water environments on the site. Individual branches and vines were cut for use in interactive educational exhibits, such as the “Bird Nest”, which accommodates groups of 20 and allows views to the pond below. Ailanthus was dried and reused as the branches enclosing the Nest.
• Recycled and/or locally produced products were used in construction, including boardwalks and interpretive display decks made from recycled plastic, protective roofs for exhibit panels made from recycled tires, and pavement materials sourced from local quarries using indigenous stone.
• Over 12,000 cubic yards of the coal silt were removed from the site and sold for reuse as fuel for power plants or manufacture into consumer products like charcoal briquettes.
• The invasive plant species present on site prior to constrction were cut, chipped, and incorporated into the soil as organic matter to support plant growth.
• The sanctuary is the site of four public environmental programs on wetlands, birding, salamanders, and the site’s history. An educational program for middle school students uses nature-themed games and activities to teach about wildlife, habitat, and human impacts.

Over 12,000 cubic yards of coal silt were removed from the site. Selling this silt at $2/cubic yard generated $24,000 which was used to help construct the project. Coal silt can be used as fuel for power plants or manufactured into consumer products like charcoal briquettes.

• All sites need to be monitored at least twice a year to determine if invasive species are present. Eradication methods will differ depending on the invasive species and should be implemented quickly and continued for as long as necessary. Phragmites and Japanese knotweed have increased at Black Rock post construction.

Project Team

Landscape Architect: KMS Design Group, LLC
Engineer (Phases 1&2): Cowan Associates
Civil Engineer (Phase 3): The Major Group, Inc.
Environmental Planner: Normandeau Associates, Inc.
General Contractor (Phases 1&2): J.A. Taddie, Inc.
General Contractor (Phase 3): Altchem Environmental Services, Inc.
Wetland Delineation: Seth Bacon Soil Consultants
Survey: Ash Associates
Graphic Designer: Communication Results
Interactive Display Designer: Playcare, Inc.
Preparation of Text for Display Exhibits: Archimedes

Role of the Landscape Architect

The role of KMS Design Group for this project was project manager and lead consultant/designer. The firm was responsible for all phases of design, client interaction, preparation of construction drawings, specifications and contract documents, and assisting in construction contract administration. KMS Design Group provided the master plan for the entire site, overseeing the project through construction.