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Building Climate Change Resiliency Along the Bay with Green Infrastructure & Treated Wastewater

Project URL link
Sponsoring Agency San Francisco Estuary Partnership
Subregions ('North Bay', 'East Bay', 'South Bay')
Counties Alameda, Santa Clara?, Marin?
Watershed Tributary San Lorenzo, Alameda Creek
Public or private land? ('Public',)
Location (lat/lon) 37.6671, -122.1567
Start Date ongoing
End Date tbd
Location Description Oro Loma Sanitary District
Building Climate Change Resiliency Along the Bay with Green Infrastructure & Treated Wastewater

Building Climate Change Resiliency Along the Bay Shoreline with Green Infrastructure and Treated Wastewater proposes to create a regional partnership of agencies that would redesign existing wastewater treatment operations by integrating natural bay ecosystem processes into a new water treatment paradigm. This new Green Infrastructure paradigm will incorporate adjacent wetland restoration projects into redesigned wastewater treatment plant operations in a manner that increases treatment plant efficacy and mitigates adverse climate change impacts both on plant operations and on the adjacent developed communities along the shoreline. The goals of the partnership are: a. to improve wastewater treatment by using natural marsh habitats to pre-treat pollutants; b. to protect vulnerable wastewater treatment plants and adjacent shorelines from rising sea levels; c. to incorporate ongoing restoration of adjacent tidal wetland habitats into a larger design to enhance those marshes and employ them as natural barriers against regional flooding and sea level rise; and, d. to determine the most cost-effective ways for wastewater plants to lower their nutrient and emerging contaminant discharges to the Bay – now a focus of concern of the San Francisco RWQCB The project partners propose to construct a series of innovative pilot ecotone slope projects along the southeastern San Francisco Bay shoreline. Participating POTWs in the form of East Bay Dischargers Association and its member agencies will collaborate with resource managers (i.e. the Don Edwards San Francisco Bay National Wildlife Refuge, Hayward Recreational Park District, and other parks/wetlands managers) and regulatory agencies (Regional Water Board, Fish and Game, DWR) to plan and permit these projects. The aim of the partnership is to expand its membership to include all Bay POTWs and adjacent land use management agencies in a unified effort to test, refine and construct the new Green Infrastructure paradigm. The first pilot project would be carried out at the Oro Loma Water Pollution Control facility in San Lorenzo where a demonstration ecotone slope would be constructed at its site. Based upon the success and lessons learned from the Oro Loma pilot, a second series of pilots is proposed for Union Sanitary District, City of Hayward, City of San Jose, and the Novato Sanitary District. Planning and permitting for this second series are included in the present project.

Building Climate Change Resiliency Along the Bay Shoreline with Green Infrastructure and Treated Wastewater proposes to establish a partnership to construct a series of pilot ecotone slope projects integrated with San Francisco Bay wastewater treatment plants. The goals of this project are: to improve wastewater treatment by using natural marsh habitats to pre-treat pollutants; to protect vulnerable wastewater treatment plants and adjacent improvements from rising sea levels; to use treated wastewater as a resource in marsh restoration; to integrate ongoing restoration of adjacent tidal wetland habitats into a larger design to employ those restored marshes as natural barriers against regional flooding and sea level rise; and to investigate new opportunities for wastewater plants to lower their nutrient and emerging contaminant discharges to the Bay by using the Green Infrastructure model.

Drinking Water Supply
Water Quality Improvement
Water Reuse/Recycling
Stormwater Improvements
Groundwater Benefits
Habitat Protection and Restoration
Flood Protection
The project involves the construction of shallow upland / high marsh ecotone slopes bayward of existing flood risk management levees. The ecotone slope serves to provide protection from rising sea levels, further removal of nutrients from secondary effluent, water reuse at a POTW; the reuse (treatment through ecotone wetlands) will improve water quality (removing nutrients; stormwater will also be treated at the ecotone; a net increase in wetlands will occur (providing increased habitat); building increased elevation wetlands around the bay will reduce flooding under rising sea level. Wastewater treatment plants of the future will be moving away from the goal of “wastewater treatment” and towards a framework of “resource recovery.” Wastewater contains two major resources that are important to the ecology of coastal ecosystems: fresh water and nutrients. Fresh water will be crucial in replenishing a coastal habitat type that has been removed from the Bay as streams were channelized—the movement of groundwater into the ecotone slope. In addition, wastewater contains nutrients that can stimulate the growth of wetlands around the Bay. The proposed project lights the way for the future framework – making the best use of the current fresh water resource.
The project provides a simple, modest cost, and environmentally friendly solution to several of the most pressing water quality and land use issues of our generation. Based upon global sea level projections, the majority of existing wetlands will be flooded up to, and including existing urban developments. We are pressed as a society to solve the problems of loss of wetlands, protection of existing infrastructure from flooding, and meet demands for higher treatment standards with greater and greater constraints on public funds. The proposed ecotone slope provides a resilient barrier to sea level rise, at a cost approximately 1/3 of traditional levee design, natural removal of nutrients and contaminants of emerging concern and restoration of a major habitat feature of the San Francisco Bay prior to 1850. If the pilot projects prove successful, the model could be expanded to 500 miles of shoreline within the SF Bay/Delta estuary, built to treat stormwater flows (including summertime ‘urban drool’), as well as to create up to 5,000 acres of moist grassland/bayland ecotone around the Bay. The project includes partners who are landowners and managers of large tracts of shoreline property adjacent to the demonstration project site. These landowner partners are keenly interested in incorporating important project elements on their property and in their operations. This is truly a collaborative project that has the support of key landowners. As pilot projects are implemented, it is reasonable to anticipate that interest and membership in the project will grow, enabling expanded implementation across the region. Working with a variety of agency types will bring lessons learned to POTWs, park districts, stormwater programs (part of cities/counties). The permitting approach established for the first pilot projects will provide a guidebook to assist in the permitting of future projects.
The project as proposed is already multi-benefit. Its implementation would result in improved climate change resiliency, improved wastewater treatment and improved ecosystem functioning. Opportunities to extend those benefits to additional sites are built into the project through establishment of the sponsoring partnership. Project partners include members who already have identified future projects. At a minimum, the establishment of a regional partnership throughout the entire South Bay would enable the benefits to be amplified and integrated across this major population center. Important design improvements and efficiencies would be realized while implementation costs would be significantly reduced. The pilot projects anticipated in 2013 could be followed by other projects around the bay. A strategy for how POTWs, regulatory, flood and resource agencies can collaborate in improving the wetlands around the Bay will also result from the project.
Yes, the team is made up of members with a wide range of resources including financial, intellectual, and willingness to devote time to the project. Many of the partners will not contribute financially, but will apply other resources.
Yes, low impact development is the essence of the project. The ecotone slope expands habitat and provides natural/low energy treatment system, while providing robust flood control and highly effective water treatment. Employing storm water runoff as a project resource is integral to the near and long-term Green Infrastructure program goals. A key element of the project is the expansion of storm water capacity at the Oro Loma wastewater treatment plant by providing a dual use average flow wetland and peak flow storage pond. Robust wet weather equalization will become essential to meet future increased treatment standards (which have reduced capacity for flow variability) as well as to provide additional resiliency to the existing treatment process. Preliminary designs have been developed for subsequent projects that incorporate similar treatment wetlands, and which employ storm water runoff as a resource for tidal marsh restoration.

Part 2 - Detail

At least 22 wastewater treatment plants around San Francisco Bay are vulnerable to the effects of sea level rise over the next century. Oro Loma Sanitary District (OLSD) has a conceptual design to create a seepage ecotone slope to restore historical moist grassland / bayland ecotone while treating reclaimed wastewater from equalization facilities and increasing its resilience to sea level rise. This project will be permitted and constructed as the first demonstration project of Building Resiliency Along the Bay with Green Infrastructure and Treated Wastewater. Additionally a treatment facility retrofit that supports wetlands accretion will be designed and permitted at Union Sanitary District, City of Hayward, and Novato Sanitary District based upon confirmation of the expected results in the pilot study.

 A scientific peer-review committee will be convened to provide technical review and guidance for the project, both for the treatment wetlands and the ecotone slope. The interdisciplinary committee will consist of leading scientists, practitioners, and managers from around the Bay who are well versed in the challenges, opportunities, and questions that the project raises. The advisory committee will provide guidance for design, monitoring design, adaptive management, and analysis of results. In addition to the design, permitting and construction of innovative treatment facilities, the demonstration project will generate design guidance and implementation recommendations that will be disseminated through outreach to the Bay Area’s many wastewater treatment facilities. The potential impact of this project is vast: if 25 percent of the Bay Area’s wastewater treatment plants are able to build ecotone slopes (based upon Oro Loma’s successful demonstration) then over 5,000 acres of moist grassland / bayland ecotone can be created around the Bay.

The aim of the partnership is to expand its membership to include all Bay POTWs and adjacent land use management agencies in a unified effort to test, refine and construct the new Green Infrastructure paradigm. The outreach component of the project will include development and dissemination of program material in print and electronic form; meetings with prospective POTW and land use management agency partners to keep them updated about progress and discuss program findings; meetings with regional policy makers to inform them about program details, including costs and benefits; meetings with community and civic organizations to build understanding and support for the project; meetings with state and federal elected officials who are ultimately responsible for oversight of program authorization and funding; and outreach to key news media providers to promote broad public awareness of and support for the project.

The demonstration projects will inform a regional strategy

Oro Loma Web Page With Feasibility Study for Project and Powerpoint Overview



Oro Loma Sanitary District is in the San Lorenzo Watershed. The San Lorenzo Creek Watershed drains 48 square miles of the East Bay Hills. The Oro Loma/Castro Valley Water Pollution Control Facility is the sole treatment plant for the San Lorenzo Creek, Bockman, and Sulphur Creek Watersheds, as well as significant portions of San Leandro Creek and Estudillo Canal Watersheds. The facility treats an average dry weather flow of 12.2 mgd (Year 2011).  

By 2050, sea level rise models show strong agreement for global sea level rise with an average of 14 inches higher than the sea level in 2000. Beyond 2050, the projections of global sea level rise depend upon the emissions generated in this century, with up to 55 inches of sea level rise projected by 2100. Given that many wastewater treatment plants are located, by necessity, at the edge of the Bay lowest elevations within a community, citizens may suffer if the plants are compromised by inundation from rising sea levels. Impaired water quality and higher temperatures can result in algal blooms and a higher potential for the spread of water-borne disease vectors. This raises key questions for resource managers in relation to climate change: identifying opportunities for tidal wetlands and mudflats to migrate landward, managing and maintaining marsh accretion, developing and planning for natural flood protection, and maintaining sufficient upland buffer areas around tidal wetlands. Furthermore, rare and valuable habitats, like the moist grassland / bayland ecotone, are a high priority for restoration and conservation.   In addition to addressing sea level rise, there are growing concerns in the San Francisco Bay related to nutrient levels and contaminants of emerging concern (CEC).  Historically, algal production in the Bay has been inhibited by a lack of light.  Now, the Bay is clearer, allowing light to pass.  Sampling throughout the Bay indicates increasing levels of chlorophyll, an indicator for potential algal blooms.  These factors are causing the Regional Water Quality Control Board to focus on the issue, collect additional data, and plan for ways to reduce nutrient loads to the Bay.  The proposed project has the capability to provide nutrient and CEC removal from the receiving waters.   

More than 50,000 acres of former and existing tidal marshes are immediately adjacent to the heavily developed urban shoreline of southern San Francisco Bay. An aging network of earthen levees provides flood protection for the developed shore. Sea level rise already is compromising the integrity of the levee system and causing increasingly frequent flooding of developed areas. This condition is forecast to get worse as sea level continues to rise. Major regional transportation corridors, including highway and rail, commercial and residential property, and critical infrastructure such as POTWs are at risk.


The project will demonstrate the advantages of employing the ecosystem services provided by a restored marsh system to provide critical flood and water quality protection benefits during the current era of sea level rise. The alternative approach of using traditional hardscape methods to safeguard existing public services would certainly be far more costly, perhaps prohibitively so.


In addition, large areas of marshes that are currently being restored would be threatened by flooding from sea level rise and contamination from failure to manage waste and storm water effectively. Further, the specific green infrastructure feature that is the centerpiece of the Oro Loma project—the ecotone—is targeted as central to the success of endangered species recovery. The Draft Recovery Plan for Tidal Marsh Ecosystems of Northern and Central California places priority on re-establishing terrestrial ecotones that provide high tide flood refuge cover and seasonal (spring) grassland foraging for the salt marsh harvest mouse. The list of wetland functions deemed to be of outstanding public interest that the proposed project will significantly improve, include: food chain production, habitat for aquatic and land species; dynamic surface water storage; energy dissipation; groundwater flow; nutrient cycling; removal of elements and compounds; retention of particulates; sequestration of organic carbon; maintenance of scarce plant community; maintenance of characteristic detrital biomass; maintenance of spatial structure of habitat, etc. The opportunity for improving these wetlands functions at treatment plants will be lost.

i. Water Supply (conservation, recycled water, groundwater recharge, surface storage, etc.)


ii. Water Quality

The seepage flow through an ecotone slope provides an effective, low cost, low energy, and environmentally sustainable method to nearly eliminate nutrient loadings and CEC’s from the receiving waters.  If proven successfully, the project has the potential to radically improve water quality in the San Francisco Bay.

iii. Flood and Stormwater Management

The project has significant flood and stormwater management benefits.  The proposed ecotone slope’s primary function is to provide an environmentally friendly, adaptable, and robust defense against flooding associated with sea level rise.  

During dry weather periods, urban stormwater can be routed through the ecotone slope to provide treatment of common fertilizer, hydrocarbon, and sediment based pollutants.  The proposed pilot project on the Oro Loma site will incorporate this concept by routing stormwater from an industrialized area into the ecotone.  

iv. Resource Stewardship (watershed management, habitat protection and restoration, recreation, open space, etc.)

The Oro Loma seepage ecotone slope will be the first Bay Area project to replicate an engineered equivalent of moist grassland / bayland ecotone of broad, flat alluvial fans that historically graded into the tidal marshes of most of South San Francisco Bay. Historically, moist grasslands vegetation (lowland wet grassland and sedge-rush meadows) were prevalent along the Estuary and in the San Lorenzo Watershed. This now rare groundwater-seep-dependent ecotone will provide important seasonal terrestrial habitat for nesting mallards and the endangered salt marsh harvest mouse (spring foraging habitat and increasingly important terrestrial high tide refuge), particularly as sea level rises.

Groundwater, soil, and vegetation interactions of wet meadows will support important carbon and biogeochemical nutrient transformation and sequestration processes that are currently excluded from diked baylands and tidal marshes disconnected from groundwater discharges.

Additionally the project will work with resource managers (Hayward Recreational Park District, Bay Trail) to ensure genuine stewardship of the wetlands around the bay.

The average resident of the area covered by Oro Loma Sanitary District has a per capita income 40 percent below the Bay Area average (US Census Bureau, 2010). The proposed project will bring in additional jobs to a lower income region of the San Francisco Bay as well as provide opportunities for lower income children to learn about the wetland habitats that surround their community.
Increases Water Supply Reliability
Advances/ Expands Conjunctive Management of Multiple Water Supply Sources
Increases Water Use and/or Reuse Efficiency
Provides Additional Water Supply
Promotes Water Quality Protection
Reduces Water Demand
Advances/Expands Water Recycling
Promotes Urban Runoff Reuse
Addresses Sea Level Rise
Addresses other Anticipated Climate Change Impact (e.g. through water management system modifications)
Improves Flood Control (e.g. through wetlands restoration, management, protection)
Promotes Habitat Protection
Establishes Migration Corridors
Re-establishes River-Floodplain Hydrologic Continuity
Re-introduces Anadromous Fish Populations to Upper Watersheds
Enhances and Protects Upper Watershed Forests and Meadow Systems
Other (Please Describe)
Increases Water Use Efficiency or Promotes Energy-Efficient Water Demand Reduction
Improves Water System Energy Efficiency
Advances/Expands Water Recycling
Promotes Urban Runoff Reuse
Promotes Use of Renewable Energy Sources
Contributes to Carbon Sequestration (e.g. through vegetation growth)
Other (Please Describe)
demonstration projects to help develop regional climate change strategy; also flood risk reduction under sea level rise; ecosystem benefits
(low) - $5,220,000(high)
Oro Loma Sanitary District
Oro Loma for Oro Loma, USD
3 years
Drought Preparedness
Use and Reuse Water More Efficiently
Climate Change Response Actions (Adaptation to Climate Change, Reduction of Greenhouse Gas Emissions, Reduce Energy Consumption)
Expand Environmental Stewardship
Practice Integrated Flood Management
Protect Surface and Groundwater Quality
Improve Tribal Water and Natural Resources
Ensure Equitable Distribution of Benefits
Reduce Reliance on the Bay-Delta
Reduce Water Demand
Improved Operational Efficiency and Transfers
Increase Water Supply
Improve Water Quality
Improve Flood Management
Practice Resources Stewardship
Other Strategies (Please Describe)
Groundwater Management Plan
Urban Water Management Plan
Water Meter Requirements
Groundwater Monitoring Requirements
AB 1420 Compliance
BMP Compliance
CEQA Compliance
Water supply reliability, water conservation and water use efficiency
Stormwater capture, storage, clean-up, treatment, and management
Removal of invasive non-native species, the creation and enhancement of wetlands, and the acquisition, protection, and restoration of open space and watershed lands
Non-point source pollution reduction, management and monitoring
Groundwater recharge and management projects
Contaminant and salt removal through reclamation, desalting, and other treatment technologies and conveyance of reclaimed water for distribution to users
Water banking, exchange, reclamation and improvement of water quality
Planning and implementation of multipurpose flood management programs
Watershed protection and management
Drinking water treatment and distribution
Ecosystem and fisheries restoration and protection
Reduced Reliance on the Bay-Delta
Projects that directly address a critical water quality or supply issue in a DAC
Urban water suppliers implementing certain BMPs as on page 17 of Guidelines
Be designed to manage stormwater runoff to reduce flood damage (PRC §5096.827)
Be consistent with the applicable Regional Water Quality Control Plans (Basin Plans) (PRC §5096.827)
Not be a part of the State Plan of Flood Control (SPFC) (PRC §5096.827)
  1. Construction of 700 feet of innovative seepage ecotone slope.
  2. Creation of 2.4 acres of rare native moist grassland/baylands ecotone
  3. Development, implementation and analysis of a robust monitoring program.
  4. Development of design guidelines and implementation recommendations.
  5. Publication and dissemination of Final Report on demonstration project.
  6. Publication of the results of outreach to POTWs and interested parties.
  7. Demonstration that a seepage ecotone slope is effective in:
    • nourishing moist grassland / bayland ecotone that is missing in most parts of the Estuary;
    • serving as a gently sloping terrestrial gradient between tidal marshes and flood levees to act as a buffer to sea level rise; and,
    • cost effective nutrient removal from wastewater.
  1. Establishment of a diverse palette of native plants, include creeping wildrye (Leymus triticoides, syn. Elymus triticoides), field sedge (Carex praegracilis), basket sedge (C. barbarae), wire rush (Juncus arcticus), brown-head rush and Iris rush (J. phaeocephalus, J. xiphioides), mixing with more salt-tolerant species such as saltgrass (Distichlis spicata) near the upper tidal edges.
  2. Establishment of increased habitat for native fauna such as Salt Marsh Harvest Mouse (Reithrodontomys raviventris) and nesting mallards.
  3. POTWs around Bay recognize benefits of climate change adaptation strategies. n. Implementation of large scale seepage ecotone slope projects around the Bay.

Project team

Part 3 - Benefits

IRWMP gi ww upload.xlsx — ZIP archive, 144Kb