Water Quality

Public and regulatory concerns over natural and anthropogenic contamination of water supplies have increased the need to understand how water quality influences the health and structure of aquatic ecosystems. To help you address water quality issues affecting beneficial uses of our water, we provide the following services:

  • Aquatic bioassessment surveys (CSBP, EMAP) and application of State (CA, OR, WA) bioassessment and antidegradation criteria
  • Synoptic and continuous in-situ water quality monitoring (pH, Temperature, Conductivity, dissolved oxygen, oxidation/reduction potential (ORP), total dissolved gas, and turbidity)
  • Water temperature monitoring network design, thermograph and meteorological station deployment and maintenance
  • Reach- and watershed-scale temperature model application (CE-QUAL, SSTEMP, SNTEMP, BasinTemp®), including interpreting possible impacts of climate change
  • Sampling and interpretation of algal and bacteriological enumeration data; mineral, metal and nutrient speciation; natural and synthetic organic compounds
  • Specialized sampling for aquatic herbicides, integrated water column sampling, inter-gravel dissolved oxygen, and sediment chemistry
  • Trace clean methods (EPA 1631) to assess mercury bioaccumulation in aquatic food webs through the testing of water, sediment, and biota
  • Total maximum daily load (TMDL) assessments for nutrients, sediment, and temperature
  • Tracer studies and water quality modeling in rivers, lakes, reservoirs, and wetlands for nutrient and pollutant removal

Stillwater Sciences provides expertise in the development of comprehensive study design and implementation for water quality assessment and monitoring in rivers, lakes, reservoirs, wetlands, and estuaries. Our staff is well-versed in regional and federal regulatory requirements as well as basic and applied research in biogeochemistry, hydrologic assessments, modeling, instream flow effects on sediment and water temperature for sensitive aquatic species, and effects of water impoundments on the accumulation and re-release of sediments, nutrients, and trace metals.


From routine water quality surveys to reservoir management, or mercury bioaccumulation studies, our staff focuses on applied water quality issues.

Download an overview of our water quality services [pdf, 3.5M] viagra online


Maia Singer
email | profile


Identifying mercury mobilization

Placer gold mining has left a legacy of mercury contamination extending from the Sierra Nevada to the Sacramento-San Joaquin Delta. Because of the risk of mercury remobilization from a heterogeneous distribution of low-levels of mercury in gold dredger tailings along the lower Merced River, Stillwater developed an innovative three-phase sampling plan for a restoration site at the Merced River Ranch that combines analysis of sediment, water, and biological tissue samples within the project area as well as comparisons to reference sites with known contamination and mining history.