OCWR Collaborates with Irvine Ranch Conservancy on Habitat Mitigation and Restoration Projects
By Leila Barker, Regulatory Compliance Manager, Amy Cruz, Senior Environmental Resources Specialist, Weena Dalby, Senior Enviornmental Engineering Specialist and Michael Gonzalez, Environmental Resources Specialist
Among OCWR’s responsibilities as landfill owners and operators has been to manage Orange County’s waste while transitioning to a resource recovery business model which includes producing renewable energy from landfill gas, materials recovery, and Source Separated Organics (SSO) facilities. OCWR’s responsibilities also extend to mitigating the biological impacts associated with their landfill projects, such as restoring disturbed habitats. This work provides critical homes for special-status ('protected') plants and animals that are managed by OCWR's C/H Group within the conserved areas of our active and closed landfill properties. Because there are populations of “protected” species inhabiting these conserved areas, we have a legal responsibility to ensure their numbers and habitats are preserved. IRC planted 820 riparian groundcover plants to fill in the created wetlands.
To mitigate or compensate for impacts to these habitats from our landfill projects, we restore disturbed habitats within conserved/protected areas of our landfill properties. Wildlife agencies prefer that we establish suitable habitats for these species elsewhere onsite and before the habitat disturbance occurs, as this decreases project costs and prevents potential notices of violation.
There are several ways to establish these habitats, including restoration which is the improvement of a damaged or pre-existing habitat. Agencies that require mitigation of unavoidable biological impacts, usually through habitat restoration, include the U.S. Army Corps of Engineers (USACE), U.S. Fish and Wildlife Service (USFWS), California Department of Fish and Wildlife (CDFW) and Regional Water Quality Control Board (RWQCB). Each of these agencies has a different set of permit requirements that must be met for our mitigation activities to be approved and considered “sufficient”.
Mitigation can also occur “offsite” or outside our landfill. For offsite habitat restoration/mitigation projects, OCWR often collaborates with qualified restoration contractors who assist with habitat preparation, installation, maintenance, monitoring and reporting activities in compliance with various permit requirements. OCWR collaborates extensively on the successful implementation of several offsite habitat restoration/mitigation projects with the Irvine Ranch Conservancy (IRC).
One of IRC’s collaboration projects with OCWR is the Trabuco Creek Mitigation Project, located in O’Neill Park. The 51acre restoration project is required by regulatory agency permits (USACE, CDFW, and RWQCB) that were issued for the Prima Landfill expansion. O’Neill Park is one of the many OC Parks and is surrounded by residential and recreational facilities including a golf course. Urban stormwater and golf course runoff discharges have been a stressor for the creek and caused the site to have a proliferation of invasive species. The project’s first steps were to remove all the invasive species such as giant reed and bladderflower vine. The next phase is an .3-acre wetland creation at an upland site as required by RWQCB, involving the installation of over 2,000 wetland-dependent plants within the light-blue polygon illustrated in the exhibit below.
This restoration project provides valuable wetland habitat consisting of a swale to collect the “nuisance flows”, a basin to receive the discharges and a drainageway to convey them to Trabuco Creek.
IRC completed fine grading at the Trabuco Creek restoration project in January 2023 and incorporated around 400 cubic yards of high-quality compost supplied by OCWR from the Bowerman Landfill into the soil at that time. Live cuttings were then planted in February 2023 to establish a willow and mulefat canopy layer. Another 100 yards of OCWR compost was incorporated into soil outside the created wetland in areas where heavy equipment caused soil disturbance. In December 2023, IRC planted 820 riparian groundcover plants to fill in the created wetland at which time more OCWR compost was utilized as a top dressing around the plants. OCWR’s compost brings organic slow-release nutrients and microbial life to soils that have experienced disturbance and degradation. Through the help of the compost, fantastic growth and vitality of the willows, mulefat, and understory riparian plants is occurring in the wetland!
As you can see, habitat restoration is an ecological investment with over $6 million spent at Prima alone in the past six years. Even the process of conservation is expensive and requires funding perpetual management via a recorded “conservation easement.” The benefits for OCWR are immense, by increasing the intrinsic ecological ethical and aesthetic values of our landfill properties.
In a future Quarterly Lift will discuss OCWR’s collaboration efforts at the Crystal Cove State Park Mitigation/Restoration Project. This photo is a “sneak-peek” showing the use of OCWR high-quality mulch around newly installed container plants!
For more information, please visit https://oclandfills.com/page/trabuco-creek-habitat-restoration
