One important element of the Santa Monica Sustainable City Program is resource conservation–specifically water conservation. The city was able to reduce water use by 13.3% between 1990 and 1998. Other major components of the sustainability program are pollution prevention and public health protection. A related noteworthy goal is to reduce dry-weather urban runoff entering Santa Monica Bay. Since 1990, that runoff has been reduced by about 92% by partially diverting flows from major storm drains to the City of Los Angeles's Hyperion Water Reclamation Plant. Since construction of the Santa Monica Urban Runoff Recycling Facility, or SMURRF, runoff entering Santa Monica Bay has been reduced even further.

The SMURRF, which began operation in December 2000, is the first full-scale, dry-weather runoff recycling facility in the United States. The facility treats low-flow dry-weather runoff from Pico-Kenter and Pier storm drains on a year-round basis and reuses the water for irrigation and toilet flushing. City irrigation sites include two parks, a cemetery, a middle school, several greenbelt roadway medians, the civic center area, and a major office building complex. The California Department of Transportation (Caltrans) has also expressed interest in reusing the water for landscape irrigation along the Santa Monica Freeway.

Approximately 500,000 gallons per day (gpd) of dry-weather flow can be treated at the SMURRF plant, adjacent to the Santa Monica Pier. The treatment train consists of coarse and fine screening to remove trash and debris, dissolved air flotation to remove oil and grease, degritting systems to remove sand and grit, microfiltration to remove turbidity, and ultraviolet (UV) radiation to kill pathogens. Reverse osmosis can also be added in the future to meet more stringent ocean discharge or groundwater recharge requirements.

In addition to its important resource conservation, pollution prevention, and public health protection aspects, the first-of-its-kind SMURRF provides an opportunity to educate the public on the importance of maintaining a sustainable environment. Education information plazas are located in plant overview areas. Art and architectural elements are designed to (1) explain the workings of the facility, (2) place the facility in the larger context of the Santa Monica urban watershed, and (3) inform citizens what they can do to decrease or eliminate pollution in urban runoff.

Background

Declaring itself a sustainable city in 1994, Santa Monica leads the state of California in the efforts to safeguard and enhance its resources, prevent harm to the natural environment and human health, and sustain and benefit the community and local economy.

Santa Monica recognizes that this is a period of great environmental crisis. With the help of local residents through workshops, surveys, community meetings, and ongoing participation, a task force developed a vision for the Santa Monica Sustainable City Program. Through a set of guiding principles and goals, the program provides a framework that addresses causes, rather than symptoms, of the environmental problems. The four main areas addressed are resource conservation, transportation, pollution prevention, and public health protection.

History

A secondary project objective is to construct an aesthetically pleasing and functional facility with an appropriate emphasis on art elements.

For many years, the residents of Santa Monica have displayed a sincere interest in politics and environmental protection, especially the protection of Santa Monica Bay. As early as 1980, residents began expressing concern over the chemical, physical, and biological pollutants entering the bay, mostly through stormwater discharges. Santa Monica Bay provides numerous recreational opportunities and greatly contributes to the quality of life for Santa Monica residents. It also helps attract millions of visitors every year who significantly enrich the local economy. However, the bay has also been the repository of treated sewage as well as all the garbage, chemicals, and oil that wash off the streets and into the storm drain system. In other words, Santa Monica's greatest asset had also become its dumping ground. In recognizing the bay's value and the need to protect it, the city set a goal to reduce dry-weather storm-drain discharges to the bay as part of its Sustainable City Program.

In 1987, the City of Santa Monica proposed to divert its dry-weather stormwater flows from the Pico-Kenter and Pier storm drains to the City of Los Angeles's Hyperion Wastewater Treatment Plant located a few miles to the south. The City of Los Angeles initially rejected this proposal, and consequently Santa Monica began considering the construction of its own stormwater treatment facility. Over the next seven years, a number of studies were commissioned, aimed mostly at determining the pollutant levels in the bay and the possible methods for reducing those pollutants. Three years later, in 1990, the Cities of Santa Monica and Los Angeles agreed to the construction of a six-months-per-year temporary stormwater diversion into the Los Angeles sanitary sewer system. The City of Los Angeles, because of its inability to handle additional flow during winter months, mandated the six-month time period. This diversion was placed into operation in 1992.

In 1995, Santa Monica retained Boyle Engineering Corporation in association with CH2M Hill to prepare a feasibility study for a proposed stormwater treatment plant. An objective of this study was to determine the potential for reuse of the treated stormwater as an alternative water source. The feasibility study, which was completed in 1996, revealed that the 4,200-ac. Pico-Kenter and Pier storm drains produced enough dry-weather runoff throughout the year that the water could be treated and economically reused in place of potable irrigation water.

SMURRF Project Goals

The primary objective of the SMURRF is to eliminate pollution of Santa Monica Bay caused by dry-weather runoff. Secondary project objectives are to:

• treat and produce cost-effective and high-quality water for reuse in landscape irrigation,
• raise public awareness of Santa Monica Bay pollution through appropriate educational exhibits at or near the treatment facility,
• construct an aesthetically pleasing and functional facility with an appropriate emphasis on art elements.

Dry-Weather Flow Quantities

Construction of the SMURRF

Dry-weather runoffs from the Pico-Kenter and Pier storm drains vary greatly throughout the dry season. The runoff is predominantly from residential, commercial, and recreational areas in the cities of Santa Monica and Los Angeles. Main components of the dry-weather runoff are irrigation and outside domestic uses, such as car washing. Minor components might also include illegal dumping, water-main and sewer-main breaks, and other nuisance urban runoff such as hillside seepage.

Credible maximum dry-weather flow estimates from the Pico-Kenter storm drain range from about 250,000 to 500,000 gpd; however, the average flows were assumed to be around 225,000 gpd based on visual observations and actual field measurements. This combines with an additional 40,000 gpd from the Pier storm drain. Peak flows from the Pico-Kenter and Pier storm drains were estimated to be 450,000 gpd and 50,000 gpd, respectively.

Flows in excess of 1 million gpd have also been occasionally observed due to unusual conditions such as water-main breaks, hydrant accidents, firefighting, and illegal upstream activities.

Dry-Weather Flow Water Quality

The presence and concentration of a variety of disease-causing, toxic, or carcinogenic contaminants in the city's stormwater appear to vary significantly with respect to time. Contaminants that have been attributed to the Pico-Kenter storm-drain effluent include:

• Trash and other debris
• Suspended solids
• Oil and grease
• Human enteric (intestinal) virus (cocksackie and vaccine strain polio)
• Heavy metals (lead, copper, zinc, and chromium)
• Organics (polynuclear aromatic hydrocarbons from soot, phthalates from plastics, pesticides, and polychlorinated biphenyls probably from transformers)

In addition to these pollutants, an epidemiological study released in 1996 suggested a significant health risk for people swimming in the Santa Monica Bay near the Pico-Kenter and Pier storm drain outlets. That report found these storm drain outlets to be significant sources of contaminants during both dry and wet weather.

Reuse Market Assessment

The two uses for product water produced from recycled dry-weather runoff are landscape irrigation and toilet flushing. Irrigation reuse of recycled wastewater is regulated by Title 22 of the California Department of Health Services, although it was developed for wastewater recycling and does not currently cover recycled urban runoff and stormwater. Regulatory compliance for the SMURRF was judged on the basis of the application of best available technology as a best management practice covered under the Los Angeles County Municipal Stormwater National Pollutant Discharge Elimination System Permit.

An initial stormwater reuse transmission and distribution system was constructed to serve major irrigation users and can be expanded in future years to serve additional users more distant from the SMURRF.

Treatment of Dry-Weather Runoff

An evaluation was conducted of various water treatment processes to determine their ability to produce a reclaimed effluent suitable for landscape irrigation and toilet flushing based on specific regulations, discharge limitations, and minimum treatment requirements.

The regulations require:

• removal of oil, grease, and large solids during the preliminary treatment process;
• removal of organic and inorganic compounds and turbidity during secondary treatment;
• removal of pathogens during the disinfection stage.

The preliminary treatment of dry-weather runoff is necessary for the proper functioning of downstream processes in the treatment plant. Debris, such as tree limbs, tires, and other floating matter, must be separated from the flow, and oil and grease must be removed. A number of preliminary treatment processes were evaluated, including racks, screens, comminutors, grinders, grit chambers, flotation units, and flow-equalization basins. Of these, the preliminary treatment process includes:

• a flow-equalization basin to stabilize stormwater flows to the secondary treatment process and
• bar screens and flotation units to remove large debris, oil, and grease. These units were deemed best from the viewpoint of space constraints, operation and maintenance, and residuals management.

Secondary treatment processes evaluated included fine screening, sand filtration, microfiltration, two-stage filtration, lime softening, reverse osmosis, granulated activated carbon, and ion exchange filters. Each of these systems was evaluated for its ability to remove the identified contaminants and for issues that limit its applicability including footprint, residuals management, and familiarity of operation and maintenance. Evaluation findings included the following:

• Sand filtration removes turbidity and suspended solids and produces an effluent that meets California Title 22 regulations required for landscape irrigation.
• Microfiltration provides the same benefits as sand filtration but has other major advantages, including a small footprint and the ability to handle a wider range of variable influent water quality. Additionally, microfiltration would allow the city to cost-effectively convert to reverse-osmosis treatment in the future and possibly use the treated water for groundwater recharge.

Several disinfection processes were also evaluated, including the use of ozone, UV radiation, and sodium hypochlorite. Selection criteria included the process footprint requirements, community safety, regulatory acceptance, piloting experience, operation and maintenance, regrowth, organics removal, cost, and environmental impact. Although all evaluated processes satisfied the disinfection requirements, the UV process was selected because of its small physical site layout requirements, minimal chemical handling, reduced environmental impact, and present low-worth cost.

A treatment train consisting of bar screens, flow equalization, air flotation, microfiltration, and UV disinfection was recommended because it can produce water that meets current reclaimed water requirements and can also meet groundwater recharge requirements with the future addition of reverse osmosis.

Public Education

The city's mandate for the SMURRF stipulated that it include a significant public education component and be responsive to its immediate neighborhood. The design team met the city's mandate, laying out the equipment in a fashion that would be logical to visitors, emphasizing each piece of equipment with a prominent base, dramatic lighting, or colorful tile work. The water, as it moves through the facility, is daylighted in five places so visitors can see the results of the purification process. From overlooks at two points, visitors can see the array of equipment. Educational material about the working of the facility, the local urban watershed, and the citizen's role in preventing pollution are presented as well.

Benefits of Integrating Art and Engineering Technology

Site-specific works of art do much more than beautify a facility. They can bring drama to signage, landscape, and architecture; present educational material in a fresh fashion; and provide talking points for personnel leading guided tours. They also can become key elements for public-relations campaigns, which can be crucial for stormwater and wastewater treatment. Outside professional circles, wastewater treatment can be a touchy subject. Wastewater treatment professionals are not always comfortable discussing details of the processes with city bureaucrats or community representatives. Artworks that address issues, such as history, chemistry, ecology, and cultural place of wastewater treatment, can make this job easier.

The inclusion of an artist on the design team had a number of significant benefits for this project. The intense colors of the tile works, the intriguing water features, the innovative architecture, and the dramatic lighting of the SMURRF integrate it with the lively atmosphere of the adjacent Santa Monica Pier. A trio of abstract tile mosaics at the foot of the stairs announces the function of the facility to pedestrians and motorists. A photomural presents images of the trees that had to be removed for the site to accommodate the new construction. In a city such as Santa Monica, which is known for its interest in "urban forestry," this kind of work can mitigate the concerns of citizen activists.

While a single work of art or a well-designed amenity will not dramatically impact the fate of a project, a comprehensive approach that incorporates an artist's insights can have a positive effect on the reception of a project by both the community and the governing bureaucracy. In the case of the SMURRF, the genuine concern for aesthetic issues signaled a sense of respect for the local citizenry. By investing this potentially mundane facility with carefully considered architecture, landscape, and art, a unique contribution was made to the quality of life in Santa Monica.

SMURRF Project Cost

Capital costs for the SMURRF were $9 million. Of this, about $6.3 million was for treatment, and $2.7 million was for the distribution system. Approximately 12% of the plant cost, or $750,000, was related to architectural components specifically designed to incorporate public art and education. Examples of art- and education-related costs are tile work and mosaics; an area designed specifically for display of educational materials; elevated (concrete) equipment mounts; and special lighting, including fiber optics.

One of the project's most expensive items was the concrete storage tank. The 500,000-gal. tank for the raw and treated water was estimated at $2 million. The tank was expensive because of tight site conditions, the need to design one side for the tank as a retaining wall for a freeway on-ramp, and the architectural treatment. The actual cost of stormwater treatment is estimated at $2.9 million ($5.80/gal. or $1.53/lit.).

Conclusion

The construction of the SMURRF not only eliminates pollution in the Santa Monica Bay but also provides a cost-effective source of alternative water supply for the City of Santa Monica. The collaborative design approach between the artist, engineer, and public works transforms a potentially unsightly wastewater facility into a major public destination. More than 2 million visitors who come to the Santa Monica Beach and its pier have an opportunity to learn about the benefits of pollution prevention and protection of the watershed. The additional cost of incorporating art in public works is minuscule compared to the long-term public educational benefits and the public acceptance of a treatment facility near a major tourist attraction.