Problem
The quality of surface water has important effects on human and ecological health. Surface water is an important drinking water source and is used for swimming, fishing, and recreation, and the quality of surface water can have profound effects on the health, diversity, and resilience of ecological communities. The New York State Department of Environmental Conservation (NYSDEC) is tasked by the U.S. Environmental Protection Agency (USEPA) to monitor ambient water quality of the State. The NYSDEC is also tasked to develop Total Maximum Daily Loads (TMDLs) for state waters that fail to meet their intended use. A critical first step in maintaining high quality of surface-water is assessment of existing conditions.
Objective and Scope
The objective of this project is to collect water quality samples in the Mohawk River Basin in cooperation with and in support of the NYSDEC. Surface-water samples will be analyzed for water chemistry and bacteria; and discharge will be measured. Samples collected as part of this project will be used as part of a larger data set, which will also contain biological data collected by the NYSDEC. This project is designed as a pilot project, to demonstrate and share capabilities, and as a collaborative proof of concept.
The sampling network within the Mohawk River Basin will include 29 sites (selected by the NYSDEC). Sampling will take place from April through October, 2016, and will include 3 main component groups: 1) field parameters, water chemistry, and discharge (6 sampling events), 2) toxicity testing (3 sampling events), and 3) bacteria (6 sampling events).
Approach
This project will assess the quality of surface water in the Mohawk River basin by collecting and analyzing water samples. To allow calculations of loads, stream discharge will be measured. Samples will be collected and analyzed using standard USGS protocols (U.S. Geological Survey, variously dated). This project will be part of a pre-existing and long-running New York State program; sites and methods will be chosen to insure compatibility with historic data.
Network Design & Sites
30 sites will be sampled throughout the Mohawk River Basin. The overall sampling network will consist of two sub-networks: ‘TMDL’ (23 sites) and ‘RIBS’ (6 sites). TMDL sites will be designed to assess loads in locations of special interest within the basin; these sites will range from wadeable tributaries (15 sites) to the mainstem Mohawk River (8 sites). RIBS sites will be part of the NYSDEC’s Rotating Integrated Basin Studies program (RIBS) and all will be wadeable streams. Site locations for both sub-networks will be determined by the NYSDEC. Draft TMDL sites are shown on fig. 1 and are listed in table 1. RIBS sites will be selected during early 2016.
Component 1 - Field Parameters, Water Chemistry, and DIscharge
Field parameters and water chemistry samples will be collected and discharge will be measured 6 times (approximately monthly) from April through October, 2016 at all sites.
Field Parameters
Field parameters, including temperature, dissolved oxygen, pH, and specific conductivity (table 2) will be measured at the time of site visits. Multiparameter meters used to measure field parameters will be calibrated daily for dissolved oxygen, pH, and specific conductance; calibrations for pH and specific conductance will use NIST traceable buffers and standards. Thermistors for temperature measurement will be compared semi-annually to readings taken with NIST-traceable thermistors. All calibrations of meters used to measure field parameters will be recorded in the instrument’s log book.
Water Chemistry
Water samples will be collected and analyzed for field parameters, nutrients, suspended sediment, physical properties, minerals, unfiltered trace elements, filtered trace elements, organic carbon, phenols, and chlorophyll-a (table 2). Additionally, at TMDL sites only, carbonaceous biological oxygen demand (CBOD) samples will be collected.
Equipment selection, equipment cleaning, sample collection, and sample processing methods will follow procedures as specified in the National Field Manual for the Collection of Water-Quality Data (U.S. Geological Survey, variously dated). Clean hands/dirty hands protocols will be used in sample collection as described in the National Field Manual. Water chemistry samples will be collected using width integrated methods and isokinetic depth-integrating samplers: wadeable streams will be sampled using equal width increments with Teflon DH-81 samplers and samples collected from boats and bridges will use equal width or discharge increments with Teflon DH2 samplers (1L bag) or Teflon D96 samplers (2L bag), as appropriate. In low-velocities where isokinetic samplers are not appropriate for use, width-integrated samples may be collected using open bottle verticals. Samples for some analyses (unfiltered mercury and total phenolics) will be collected at a single vertical in the centroid of flow. Samples will be composited into a churn splitter for division into bottles for delivery to laboratories. Samples for some analytes (including phosphorus) will be field filtered and/or acidified. Samples for most analyses (excluding mercury and suspended sediment) will be chilled immediately after field processing and until delivery to the appropriate laboratory. Acid neutralizing capacity samples will be laboratory analyzed for consistency with historical NYSDEC data.
Most samples will be analyzed at the USGS New York Water Science Center Soil and Low Ionic Strength Water Quality Laboratory (NYWSC-LISL); additional labs will be used for selected analytes, including the USGS National Water Quality Laboratory (NWQL: TKN, phosphorus, and residue on evaporation), USGS Kentucky Sediment Laboratory (KYSed: suspended and volatile solids), USGS Wisconsin Mercury Laboratory (WIML: unfiltered mercury), and a contract laboratory (total phenolics, CBOD, and chlorophyll-a) (table 2).
Discharge
Discharge will be measured at the time of collection of water chemistry samples to enable computation of loads. Discharge data from a USGS gaging station will be used where available. Discharge at ungaged streams will generally be measured using hydroacoustic technology and velocity-area methods. Wadeable streams will be measured using the midsection method and an acoustic Doppler velocimeter (ADV), and deeper streams will generally be measured from boat or bridge using the velocity-area method with an acoustic Doppler current profiler (ADCP). More information about discharge measurement methods can be found in Turnipseed and Sauer (2010).
Component 2 - Toxicity Testing
Water samples for Ceriodaphnia dubia toxicity testing will be collected 3 times at selected sites (table 1), including 2 mainstem Mohawk River sites (West Schuyler and Cohoes), the 15 TMDL tributary sites, and the 6 RIBS tributary sites. Toxicity testing samples will be collected as grab samples during site visits for water chemistry sample collection and will be delivered to the NYSDEC for analysis.
Component 3 - Bacteria
Samples for bacterial analysis will be analyzed for fecal coliforms (table 3) at a local laboratory. Bacteria samples will be collected separately from water chemistry samples as grab samples, using sterile containers provided by the analyzing laboratory. Bacteria samples will be collected 6 times from April through October, 2016 at all sites; samples will either be collected approximately monthly, or all in one month, to meet water quality standard evaluation requirements, at the discretion of the NYSDEC. Samples will be chilled immediately after collection and delivered to the laboratory within 6 hours of collection.
Project Location by County
Greene County, NY, Albany County, NY, Delaware County, NY, Fulton County, NY, Hamilton County, NY, Herkimer County, NY, Oneida County, NY, Lewis County, NY, Madison County, NY, Montgomery County, NY, Fulton County, NY, Schenectady County, NY, Saratoga County, NY
