Monitoring
Delivering scientifically sound monitoring programs that support informed water quality management. We design and implement targeted monitoring strategies that answer management questions, evaluate program effectiveness, and meet regulatory compliance requirements throughout California.
Core Services
Pollutant source identification and assessment
Watershed pollutant load evaluations
Trash, bacteria, legacy contaminant, and pesticide control programs
PFAS and emerging contaminant assessments
TMDL implementation planning and reporting
Source investigation and tracking studies
Best management practice evaluation
Regulatory compliance strategy
Regional collaboration and program coordination
Reliable monitoring provides the scientific foundation for effective water quality management and informed regulatory decision-making. EOA designs and implements monitoring programs that answer critical management questions, evaluate environmental conditions, and measure the effectiveness of water quality improvement efforts. Our team combines technical expertise with innovative monitoring approaches to deliver high-quality data that support compliance, watershed management, and adaptive program implementation.
Highlighted Projects
Low Impact Development (LID) Effectiveness Monitoring
Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP)
San Mateo Countywide Water Pollution Prevention Program (SMCWPPP)
SF Bay Regional Creek Status Watching Our Watersheds (WOW) Trash Flow Monitoring Projects Program Design
Highlighted Project
Low Impact Development (LID) Effectiveness Monitoring
Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP) / San Mateo Countywide Water Pollution Prevention Program (SMCWPPP)
- EOA works with Santa Clara Valley Urban Pollution Prevention Program (SCVRUPPP) and San Mateo Countywide Water Pollution Prevention Program (SMCWPPP) on LID effectiveness monitoring projects to satisfy Municipal Regional Stormwater NPDES Permit (MRP) requirements. EOA collected and monitored composite samples for total mercury, total polychlorinated biphenyls (PCDs), total suspended solids TSS), per- and polyfluoroalkyl substances (PFAS), total petroleum hydrocarbons (TPH), total dissolved copper, total hardness, and hydrogen ion concentration (pH). Most recently, as part of the 2024-2025 work year, EOA has:
- Created a robust LID monitoring plan to complete sampling events during the permit term, completed ongoing maintenance, and addressed concerns raised during work year 2023-2024.
- Facilitated the Technical Advisory Group (TAG) of impartial science advisors and Water Board staff that advised on specific monitoring plans.
- Implemented flow and precipitation monitoring methods, such as influent collection trays and calibrated tipping-bucket rain gauges.
- Drafted and submitting the Urban Creek Monitoring Report as required by MRP provision C.8.h.iii.
Successfully identified data points for future comparison, monitored influent and effluent rates at multiple sites between two counties, and identified clear objectives for future work years.
Highlighted Project
SF Bay Regional Creek Status Watching Our Watersheds (WOW) Trash Flow Monitoring Projects Program Design
Alameda Countywide Clean Water Program, Contra Costa Clean Water Program, San Mateo Countywide Water Pollution Prevention Program, Santa Clara Valley Urban Runoff Pollution Prevention Program, Solano Stormwater Alliance
- EOA, has led the efforts with the ongoing Watching Our Watersheds (WOW) Trash Outfall Monitoring Project (MP) to help achieve trash flow reduction goals required by the Municipal Regional Stormwater NPDES Permit (MRP) 3.0, provision C.8.h.iii. In partnership with and across several countywide programs during the 2024-2025 work year, EOA:
- Sampled three storm events at 10 monitoring locations and collected 30 samples using trash net devices for trash sampling and monitoring water flow with water level sensors in outfall pipes.
- Performed qualitative assessments of catchment areas, including observations of trash sources and trash controls.
- Categorizing and measuring total trash collected per catchment area during each storm event.
- Calculated annual trash loading rates per catchment site based on average trash volume per sampled wet weather event, water flow data per wet weather event and total events in a rainy season.
The work performed by EOA, on behalf of clients identified successful compliance to the MRP and identified specific areas of focus for the 2025 Work Year.
