Water is arguably the most important element of sustainability.

Most people don’t think about what happens to the water they fl ush down their toilets, or that washes down into their drains and sinks. But what happens to that water next is an extremely important key in protecting the earth’s natural resources.

More than 200 million gallons of wastewater fl ows to the Orange County Sanitation District every day. Treating such a large volume of wastewater and doing it in a safe and reliable way is an ongoing balancing act—and a classic example of what sustainability is all about.

We actively take part in recycling efforts at virtually every step of the treatment process. Using the latest technologies and combining them with cutting edge research helps us create our own version of the science of sustainability.

Sus•tain•abil•i•tyTaking part in activities that protect the earth’s ecosystems, meeting the needs of the present generation without compromising the ability of future generations to meet their own needs.

One ton of the produced E-fuel can generate approximately one megawatt of electricity, minimizing fossil fuel consumption.

We also have an agreement with Synagro Technologies, Inc. in Kern County, California to take our biosolids and create organic compost. Aft er the biosolids are processed by Synagro, the commercial grade

compost is used as an amendment to build healthy soils at commercial, farming and residential locations throughout Southern California.

Another byproduct from our processing of biosolids is methane gas. Rather than burn off this gas, we capture it, compress it and use it to run our own central generation power facility. We’ve been doing this for about 15 years and because of our eff orts, we save about $6.3 million annually in power costs, generating enough power to meetthe needs of about 7,000 people.

Recycling is a fundamental part of our operations. We actively engage in a variety of programs andprocesses that return clean water, solids and air back to the environment.

OCSD partnered with the Orange County Water District to build the Groundwater Replenishment System. Th is project recycles up to 70 million gallons of water a day back into the environment. Some of this water is used to create a barrier to protect our deep water aquifer from seawater that would otherwise intrude on local fresh water supplies. Th e balance of the water is pumped to basins where it eventually fi lters back into Orange County’s drinking water supply.

Commissioned in January 2008, OCSD delivered more than 15 billion gallons of treated water to the GWR System in its fi rst year of operation. It has become part of the sustainability equation to help meet the water needs of Orange County for years to come.

Recycling is a vital part of the sustainability equation.

Sustainability is a major factor in how we manage our organic solids—better known as biosolids. Biosolids are removed from wastewater during our processing and because theyare nutrient-rich, we are able touse them as fertilizer on farmland.It’s a good thing too, because weproduce about 500 million poundsof biosolids annually.

As part of our biosolids solution, we have entered into a unique long-term agreement with EnerTech Environmental, Inc. in Rialto, California. EnerTech heats and dries our biosolids, creating a charred pellet called E-fuel that is used as a coal substitute to fuel cement kilns. Aft er the pellets are burned, the resulting ash is used to create cement, resulting in virtually no waste that is returned back into the environment.

By the end of 2009, EnerTech will generate about 170 tons per day of E-fuel that will off set over 85,000 tons of carbon dioxide emissions per year in Southern California.

Sustainability is part of our environmentally friendly culture.

Treated wastewater from our two facilities fl ows through an ocean outfall pipeline that releases water almost fi ve miles out and 200 feet deep into the ocean. To ensure the protection of marine life and public health, we’ve maintained an extensive ocean monitoring program for over three decades. As part of this eff ort, we perform three types of monitoring: core-monitoring, regional monitoring, and special studies.

Our staff takes water samples from the surf zone along 17 miles of coastal Orange County stretching from Seal Beach to Crystal Cove. We then take these samples—along with other water, fi sh, ocean sediments, biosolids,and air samples—and conduct 100,000 tests annually at our lab facilities in Fountain Valley. It’s an important part of how we ensure our natural resources are clean and safe.

On board the Nerissa, our 60-foot ocean research vessel, we sample 35 square miles of ocean, testing and monitoring sea life and sediments from the ocean fl oor to make sure no pollutants cause harm to marine life.

Our core-monitoring program includes measurements, sample collection and analyses, and data interpretation to evaluate potential impacts of treated wastewater on coastal water quality, and the community health of the fi sh and small animals living in the sediments near our outfall.

We share our ocean monitoring data with other agencies and conduct regional studies that measure environmental conditions in the Southern California Bight—the area from Santa Barbara to Ensenada, Mexico. These results provide valuable information that is used to improve our understanding of regional-scale issues and provide a larger perspective for comparisons with data collected for the core program and special studies.

OCSD also conducts special studieson important coastal concerns not addressed by routine monitoring. These projects analyze oceanographic and biological elements that enhance data interpretations and data quality of the core program.

A Regional Approach

Urban runoff has the potential to harm the environment, so rather than let bacteria-laden runoff fl ow directly into the ocean, we capture and treat about 2.5 million gallons per day during dry weather. We collaborate with otheragencies and nongovernmental organizations on a regional scale to protect Orange County’s beaches from runoff , making our coastal beach areas healthier and more sustainable.

Simply put, we are extremely committed to protecting the environment. All of our recycling efforts tie into an environmentally friendly culture. But there are several other things we do to protect and preserve Mother Nature as well.

Our protection eff orts extend to an active residential and business public outreach program. Th is supplements our regulatory and monitoring eff orts and is an ongoing eff ort to remind the public not to put harmful chemicals and products into the waste stream.

For example, one of our outreach programs involves educating thepublic on how to properly dispose of pharmaceuticals. Some drugs are harmful to the environment, so we actively remind the public to not put drugs down the drain. Instead, we encourage people to mix old and left over medications with coff ee grounds or dirt and throw themaway in the trash.

Powering Cars withHydrogen Fuel Cell TechnologyIn a collaborative project between the Orange County Sanitation District, the University of California, Irvine, Fuel Cell Technologies, Air Products, the U.S. Department of Energy, and the California Air Resources Board and the South Coast Air Quality Management District, an $8 million demonstration project is a cutting- edge example of sustainability at work.

Methane is one of the byproducts of processing the biosolids removed from wastewater and for years, we have captured that methane and turned it into electrical energy and heat to drive our operations. When it comes online, we’ll use new, low- emission technology to process methane gas and produce not

only electricity and heat more effi ciently, but also hydrogen fuel for cars.

The methane comes from the sewage plant’s digesters, large circular tanks that treat sewage solids. The sludge is heated, allowing bacteria to break down the sludge which produces methane and carbon dioxide. The Sanitation District uses most of the methane to generate electricity—up to 225,000 kWh per day.

With this new fuel cell technology, hydrogen will be separated from the methane and pumped into storage tanks to produce enough hydrogen to power up to 50 fuel cell car fi ll-ups a day.

A Partnershipto Recycle WaterUntil recently, most of the water treated at the Orange County Sanitation District was released back into the ocean. But with water demands continuing to rise, the onset of drought and potential water shortages, and the need to protect our existing water supplies, we partnered with the Orange County Water District to create the Groundwater Replenishment System. This system can now recycle enough water to meet the needs of 500,000 Orange County residents.

Treated wastewater that has under-gone a stringent source control process fl ows from the Sanitation District to the Orange County Water District where it then undergoes advanced treatment that produces ultra-pure quality water.

The fi rst step is microfi ltration which is a low-pressure membrane fi ltration process that takes small suspended particles, bacteria and other materials out of the water. Followed by a second membrane fi ltration, reverse osmosis, a process that forces water through the molecular structure of several sheets of thin plastic membranes to fi lter out minerals and contaminants, including salts, viruses, pesticides, and other materials.

Water is then exposed to ultraviolet light, just like instruments in medical and dental offi ces, to provide disinfection. Hydrogen peroxide is combined with the ultraviolet light to create an advanced oxidation reaction that eliminates any remaining impurities in water by breaking them down into harmless compounds.

Once purifi ed, the water is either pumped underground near the coast to replenish a seawater intrusion barrieror it is sent to basins in north Orange County where the newly purifi ed water fi lters into the ground and blends with existing groundwater.

We are doing the work of Mother Nature.

The Sanitation District utilizes many of the same tools as Mother Nature to treat the wastewater we receive each day. We just optimize the process so that what takes days in nature only takes hours in our treatment system.

Just as gravity operates in nature, we use gravity by fl owing wastewater from higher elevations throughout Orange County to our two low-lying treatment plants near the coast. Gravity is also the main concept behind the settling out and separation of larger particles that takes place once the wastewater reaches our facilities.

In nature, if you pick up a rock in a shallow stream it may be covered with a green-gray, slippery growth called zoogleal slime—a mass of microbes—that feeds on organic material in the stream. During our secondary treatment process, we use those same organisms grown on rocks to remove organics from the wastewater. Th e microorganisms—mostly single celled protozoa, amoeba, ciliate, and rotifers—eat organic waste that has been reduced to sugars and proteins.

At our wastewater treatment plant in Fountain Valley, we use trickling fi lters containing 12 million square feet of plastic honeycomb surface that allow the zoogleal slime to live and grow. Th e two trickling fi lters can treat 30 million gallons of wastewater each day.

Live bacteria that eat hydrogen sulfi de gas are also used in our biotowers to remove foul smelling odors from the air in our treatment plant processes. Using these naturally occurring “good bugs” reduces the need to use costly and toxic chemicals to do the job. And the best part is, the good bugs work for free!

Protecting and recycling our water supply isa vital element in the science of sustainability.

At the Orange County Sanitation District, we’re combining technology, innovation and partnerships to help ensure future generations will have the resources they need to live on a healthy planet for decades to come.

http://www.ocsd.com