Leadership & Departments

Leadership Team

CWS Executive Leadership

The CEO of Clean Water Services speaks while standing at Fernhill wetlands. The CEO of Clean Water Services speaks while standing at Fernhill wetlands. Employee, CEO, Diane Taniguchi-Dennis, Apparel, Clothing, Finger, Human, Long Sleeve, Person, Sleeve

Diane Taniguchi-Dennis, P.E., BCEE, MBA, Chief Executive Officer

Diane was appointed by the Board of Directors as CWS’s first CEO in 2018. She is an internationally recognized water leader who serves on the boards of the National Association of Clean Water Agencies and Willamette Partnership. She is part of the Research Advisory Council for the Water Research Foundation and the Advisory Board of World Water Tech North America.

Diane’s vision and actions as a leader draw upon her childhood in Hawaii, her nearly 40 years as an engineer focused on water resources, and her wide-ranging study of organizational systems. A self-described “child of water,” Diane learned early “that there is an interconnectedness between land and air, water and wind, and family or ‘ohana.” She is dedicated to creating an organization that is resilient to the challenges of the coming decades and is a place where all employees can learn, grow, thrive, and belong. 

Nate Cullen, Chief Operating Officer

Nate was named CWS’ first Chief Operating Officer in 2021. He oversees the accomplishment of CWS’ vision, mission, strategic initiatives, and overall goals as they relate to operations, maintenance, planning, engineering, regulatory affairs, and business operations. Nate also oversees the preparation of and makes recommendations to the CWS operating budget and oversees coordination with regulators and stakeholders. 

Nate joined Clean Water Services in 1992 as a project engineer and was named Treatment Plant Services engineering manager in 2002 and Wastewater Treatment Department director in 2012. 

Mark Jockers, Chief of Staff

Mark was named CWS’ first Chief of Staff in 2021 with responsibility for ensuring enterprise-wide accountability to strategic priorities and performance metrics, engaging and deepening the utility’s relationships with external partners, and overseeing CWS’ government and legislative strategies. He joined CWS in 1991 and most recently served as the Government & Public Affairs director from 2005-2020. 

Jack Liang, Chief Strategy Officer

Jack Liang became CWS’ first Chief Strategy Officer in October 2021, leading the development and deployment of integrated and cohesive business strategy as well as investment strategy. Jack is a Certified Public Accountant and a Chartered Global Management Accountant.

Joe Gall, Chief Utility Relations Officer

Joe became CWS’ first Chief Utility Relations Officer in May 2021. He oversees the Regional Utility Services department, which focuses on strengthening relationships with CWS partners surrounding issues such as economic development and community planning, strategic integrated planning and policy development, and utility intergovernmental relations to support regional water resources management. 

Kathleen Leader, Chief Financial Officer

Kathy was named Chief Financial Officer in 2019 and is responsible for all financial activities for CWS including the programs and activities relating to accounting, budgeting, financial forecasting and planning, debt management, financial management information systems, reporting systems, capital improvement planning, purchasing and contracts, and financial policies and procedures. She joined CWS in 2007 as accounting services manager and was appointed finance manager in 2012. 

Gerald Linder, General Counsel

Jerry joined Clean Water Services in 1996 to head its Legal Services Department. He serves as co-chair of the Legal Committee for the Association of Clean Water Agencies of Oregon.

Learn more in our Organizational Chart (PDF).


Clean Water Services Board of Directors

Clean Water Services is a county service district organized under Oregon Revised Statute 451. Although we maintain a close working relationship with Washington County, CWS is a separately managed and financed public utility. Our Board of Directors is composed of the individuals who are elected as Washington County Commissioners:

  • Kathryn Harrington, Chair – at large
  • Nafisa Fai – District 1
  • Pam Treece – District 2
  • Roy Rogers – District 3
  • Jerry Willey – District 4

View past and present agenda items on the Washington County iAgenda site.


Clean Water Services Advisory Commission

The purpose of the Clean Water Services Advisory Commission (CWAC) is to review and discuss major policy issues and programs related to the management of water resources in the Tualatin River Watershed and make recommendations to Clean Water Services’ Board of Directors. 

Learn more about CWAC members, meetings, and minutes.

The Clean Water Services team is dedicated to serving over 600,000 customers in the Tualatin River Watershed