MMWD at Work

MMWD’s skilled workforce operates our water system 24 hours a day, 365 days a year. Providing safe, reliable water requires a broad range of expertise, from engineers who plan and design our system, chemists who test for water quality, service crews who maintain the pipelines, biologists and ecologists who ensure the health of our watershed, responsive customer service representatives and many others. Read on to meet some of the people who help deliver your water from Tam to tap.

Christina, Water Conservation Specialist II


As one of MMWD's Water Conservation Specialists, Christina’s days are busy and varied. She may spend her morning at a customer’s home identifying a problem with their irrigation controller, and in the afternoon visit an elementary school to teach first graders about the water cycle and the importance of the Mt. Tamalpais watershed.

When asked what she enjoys most about her 11 years here at MMWD, Christina said, “At the end of the day, feeling like I’ve sincerely made a difference. Helping a customer find and stop a leak that may have been wasting hundreds (or even thousands) of gallons of water per day is at the top of my list.”

In addition to helping our customers find and stop leaks, our Water Conservation Specialists work behind the scenes to review landscape projects and plans to make sure they comply with the State’s Model Water Efficient Landscape Ordinance.

If it sounds like Water Conservation Specialists know a lot about a lot, you’re right. “There’s so much to know! And so much to keep learning too." says Christina. "Questions from our customers always keep me on my toes. During the same visit, I might get asked for advice on how to fix a leaky toilet; but also about state water regulations, rates, and MMWD’s water treatment process.”

MMWD's Water Conservation Specialists wear many hats, keeping the district at the forefront of advancements in conservation while helping our customers find ways to reduce their water use and their water bills.

Matt Cerkel

Matt, Park Ranger

Even after 23 years on the job, MMWD Park Ranger Matt Cerkel never knows what each day will hold. As one of six rangers tasked with protecting MMWD’s nearly 22,000 acres of watershed land, Matt functions as peace officer, wildland firefighter, EMT, search and rescue specialist, naturalist, historian and educator. Watch the video below to learn more: 

Dewey, Supervisor of Reclamation and Backflow  

Dewey Sorensen

MMWD Supervisor of Reclamation and Backflow Dewey Sorensen is on the front lines of ensuring a safe and reliable  drinking water supply. What is backflow? Backflow is the reversal of water flow back into the public drinking water system. This is usually caused by backpressure, which occurs when downstream pressure rises above the supply pressure. Backflow events occur daily in water systems. Where backflow events become a concern is when a water line is connected to a source of pollution, such as irrigation water (with various dirt particles), and gets mixed in with the clean public drinking water. 

Dewey and the Backflow and Reclamation team of Alex Amour and Nole Studley work tirelessly to prevent backflow events by identifying cross-connections (temporary or permanent locations between public drinking water and a consumer's water system that could potentially introduce contamination or pollution into the public or private drinking water system) and ensuring the installation of backflow prevention devices. Backflow preventers installed at cross-connections must be inspected annually and Dewey’s group ensures this happens to the tune of about 8,700 inspections a year.

According to Dewey, “This position is the pinnacle in the industry, and I am very humbled by the opportunity to be part of the multi-barrier approach of protecting the public water supply from contamination. Every day I am thrilled to be able to bring current industry-wide best practices into operation here at MMWD. This freedom has allowed the Reclamation and Backflow Group at MMWD to become one of the most efficient and progressive in the country.”

We’re happy to have you here, Dewey, and we’re sure our customers appreciate your efforts to make sure their water is safe.

Chris Nanney

Chris, Water Quality Lab Manager


Marin Municipal Water District’s water goes through over 120,000 quality tests in a year to ensure what arrives at your home’s tap is safe to drink. Who oversees many of tests, and ultimately, the health and safety of our customers? Chris Nanney, our Water Quality Lab Manager.
During his 20 years (and counting!) at MMWD, Chris has worked his way from an entry level Chemist, to managing the lab — gaining invaluable experience along the way. 

Chris oversees all water quality field staff as they gather samples from different points in MMWD’s water distribution system.

He also manages a team of chemists that test the samples to ensure our water meets or exceeds all state and federal drinking water standards. With ever-changing regulations and improved testing technology and equipment, there is rarely a dull day in the lab. “MMWD keeps me challenged, as there is always something new for us in the lab world.” As MMWD’s resident water quality expert, Chris finds answering customer questions and troubleshooting T&O (taste and odor) concerns especially rewarding. 

With a professional like Chris working behind the scenes, our customers can rest assured their water not only tastes great, but is safe to drink, and that is an irreplaceable asset to our community.