We Deliver Results.

One Water Consulting

Our Mission

Our services extend beyond traditional consulting.  We provide a one-stop shop for strategic planning and regulatory compliance support to a wide variety of public and private sector entities.  Our special set of skills enables us to provide advice, identify future needs, navigate through a complex web of laws and regulations, craft intelligent and cost-effective solutions and communicate clearly to stakeholders at all levels.  Not only do we provide a high-quality product that satisfies our clients’ objectives as quickly as possible, but our insightful, innovative, and state-of-the-art technical solutions are delivered with strong communication and presentation skills. 

The One Water Team

James F. Cosgrove, Jr., P.E.

James F. Cosgrove, Jr., P.E.


Jim Cosgrove is the President of One Water Consulting LLC and a recognized expert in the fields of water quality modeling; regulatory support; wastewater, watershed, and stormwater management; and litigation support.  He has over 35 years of experience as an environmental engineer and consultant.  Jim’s expertise in NPDES permit support, stormwater analysis, water quality studies, and watershed management have led to a reputation of excellence in working with regulators, providing expert testimony, and developing innovative, effective and cost-effective solutions.  Jim holds a bachelor’s degree in civil engineering from Lafayette College and master’s degree in environmental engineering from Cornell University.  He is a registered professional engineer in the State of New Jersey.


Ph: 609-808-2010

Brian J. Friedlich, P.E.

Brian J. Friedlich, P.E.

Managing Engineer

Brian Friedlich brings more than 15 years of expertise in the field of water resources engineering. His focus has been on stormwater management, watershed planning, wastewater treatment and collection system rehabilitation.  He has led the design, permitting and construction administration for many large-scale infrastructure improvement projects throughout the region.  Brian has also developed a specialty in green infrastructure technologies for compliance with NJ stormwater management regulations.  He regularly gives presentations at conferences and continuing education courses on topics related to stormwater management and permitting.  Brian holds a bachelor’s degree in environmental engineering from Tufts University and a master’s degree in environmental engineering from the Massachusetts Institute of Technology.  He is a registered professional engineer in the State of New Jersey.



Joseph W. Schwarz IV, P.E.

Joseph W. Schwarz IV, P.E.

Senior Project Engineer

Joseph Schwarz has a broad background in program management and environmental engineering, with over 15 years’ specific experience in watershed monitoring and modeling, database management, and program management of large-scale projects. He has collected water quality samples, analyzed data, and prepared quality assurance sampling plans for TMDL, phosphorus impairment, dilution, metals translator, water effect ratio, anti-degradation, and local limits studies. Joseph has also performed construction observation services for water supply and wastewater treatment infrastructure projects, and directs One Water’s safety program. Joseph holds a bachelor’s degree in environmental engineering from the University of Notre Dame and a master’s degree in water resources systems engineering from Cornell University. He is a registered professional engineer in the State of New Jersey.



Caitlin Gilvey

Caitlin Gilvey

Water Resources Engineer

Caitlin Gilvey has two years’ experience in water resource engineering including water and wastewater treatment as well as green infrastructure design. She has conducted research and water quality modeling in addition to developing standard operating procedures for addressing emerging environmental pollutants in both surface water and drinking water.  She helps to conduct stream studies involving developing and implementing sampling plans, contributes to design projects for both water and wastewater treatment plants, performs data analysis and water quality modeling, helps to address NJPDES permitting issues, and designs stormwater management systems. Caitlin holds a bachelor’s degree in environmental engineering as well as a master’s degree in bioenvironmental engineering from Rutgers University.