Third Rock Consultants

Water Quality Monitoring

In the area of water quality consulting, Third Rock's engineers, aquatic ecologists, wetland scientists, and data analysts work together to provide a unique level of expertise unequaled in environmental consulting.  We are proficient in designing water quality monitoring strategies, sampling protocols and methodologies, and complex data analysis and interpretation.


We prepare monitoring plans for projects ranging from a few square miles to hundreds of square miles for submittal to local, state, and federal regulatory agencies. When developing comprehensive monitoring strategies, we utilize GIS analysis followed by field evaluation to select sampling locations. Regardless of the spatial scale, strategic placement of sampling stations is crucial for determining the sources of surface water pollution, especially in mixed-use landscapes.  As agencies increasingly require standardized quality levels from monitoring data, we also routinely develop required Quality Assurance Project Plans (QAPPs) for monitoring projects. QAPPs are prepared to document the planning, responsibilities, procedures, implementation, assessment, and validation procedures required, and provide guidance for assuring that projects are successfully executed to meet the established objectives.


Third Rock can customize a pollutant source assessment and monitoring scheme to match your watershed needs.   We are well-trained and uniquely experienced to execute the following types of water quality monitoring:  biological, chemical, and bacteriological.



The composition of aquatic communities can be very useful in estimating water quality, habitat conditions, and the overall ecological health of streams and rivers. Third Rock typically assesses two aquatic communities, fish and benthic macroinvertebrates,to yield the most accurate representation of a stream's biological health.  


Macroinvertebrates are affected by all environmental stream variables including physical, chemical, and biological conditions. Since they cannot escape the pollution, their presence is indicative of both short-term and long-term stream health from the cumulative effects of pollution.  


Similar to macroinvertebrates, the composition of fish communities can be very useful in estimating water quality, habitat conditions, and the overall ecological health of streams and rivers. Using fish community assessments in conjunction with macroinvertebrate results often yields the most accurate representation of a stream's biological health. The advantages of using fish communities in biological monitoring are their utilization of multiple trophic levels, widespread distribution within aquatic habitats, and availability of extensive life history information. Compared to macroinvertebrates, fish populations are more stable throughout the year, though their high mobility can sometimes affect data collection. 




Chemical monitoring assists clients in determining whether or not specific pollutants are negatively affecting the designated uses of a waterbody. These pollutants can be compared to water quality standards, permit limits, or scientific literature to indicate whether health thresholds are exceeded and what the potential sources may be. Third Rock’s water quality team has successfully executed sampling plans in a wide variety of conditions and parameters.  We have quickly deployed crews to 100 sampling sites over an area of over 400 square miles to capture a snapshot of wet weather conditions, and we have used continuous water quality monitoring over an extended period with Hydrolab in-situ meters. We are equipped to sample surface water, groundwater, soils, lakes, and other environments. We use state-of the-art flow meters paired with surface water grab samples to quantify pollutant loads and utilized grab samples, passive samplers, and composite samplers in order to capture representative samples for our clients.




Third Rock is proficient with various approaches to microbial source tracking (MST), having used a variety of bacteriological, chemical, visual and DNA tracers to identify fecal pollution sources. These MST approaches can assist clients in clarifying the relative contributions of different fecal sources, such as human waste, agriculture, or pet waste, so the most cost effective best management practices can be implemented to address sources.

Macroinvertebrate Sampling
Chemical Monitoring
Fish Survey
Stream Monitoring
Fish Survey