Department of Environmental Conservation

D E C banner

Water Quality Monitoring

On this page:

Water Quality Monitoring

DEC monitors the waters of the New York State. Monitoring and assessment goals include:

  • Identifying overall quality of waters.
  • Identifying long-term water quality trends.
  • Characterizing naturally occurring or background conditions.
  • Establishing baseline conditions for use in measuring the effectiveness of site-specific restoration and protection activities.

Monitoring strategies for DEC's water quality monitoring include the following:

  • The Screening Network provides a narrative assessment of water quality at sampling sites statewide based on biological assessment using macroinvertebrate community analysis, or biomonitoring, as well as measures of acute toxicity in the water, physical habitat evaluation and water chemistry. Locations identified during the screening year may be selected for additional sampling during the following year.
  • Special Surveys are designed to answer specific questions regarding habitat and water quality and may employ multi-media sampling-depth integrated water chemistry, bottom sediment and invertebrate tissue chemistry, toxicity testing macroinvertebrate or fish community assessments, habitat assessment-depending on the focus of the survey.
  • The Routine Trend Monitoring Network provides information for establishing basic water quality characteristics and baseline conditions, and for identifying long-term trends by sampling at fixed sites across the state, conducted each year, regardless of the rotating cycle.

Rotating Integrated Basin Studies (RIBS)

The objectives of the Rotating Integrated Basin Studies (RIBS) program are to monitor and assess water quality of rivers, streams, lakes, and groundwater of New York State. The program is designed to monitor all major drainage basins in the state every 5 years (Figure 1). The years listed in the RIBS monitoring cycle represent a screening year; additional targeted sampling may occur in subsequent year's based on analysis of screening year data.

Specific RIBS monitoring programs include:

  • River and Stream Monitoring
  • Lake Classification and Inventory (LCI)
  • Groundwater Monitoring

More details on methods, assessment criteria and their application in the RIBS programs are contained in the Quality Assurance Program Plans and Standard Operating Procedures for each of the sampling media. These documents are available from NYSDEC DOW Water Quality Assurance webpage.

River and Stream Monitoring

The River and Stream Monitoring program, was initiated in 1972 and is primarily focused on fulfilling the Screening Network and Special Survey monitoring strategies. The DEC Screening Network targets approximately 75 river and stream monitoring locations for the collection of water quality data annually in 3-4 of the 17 basins in New York State per the RIBS monitoring cycle. An additional subset of the river and stream locations may be sampled periodically each year for the completion of Special Surveys based on annual priority.

Water data quality data collected through DEC river and stream monitoring Are determined by specific project requirements and based on the overarching monitoring strategy.

Data Collection may include:

  • Biological monitoring of resident macroinvertebrate communities
  • Field parameters collected within the water column using a multi-parameter probe
    • Temperature
    • Dissolved Oxygen
    • pH
    • Specific Conductance
    • Salinity
    • Chlorophyll A
    • Phycocyanin
  • Laboratory parameters collected at river and stream monitoring locations
    • Alkalinity
    • Chlorophyll A (water column only)
    • Hardness
    • Nutrients (phosphorus and nitrogen)
    • Salt parameters (sodium and chloride)
    • Sulfate
    • Toxics (including PCBs, PFAS, and others)
    • Total and dissolved metals
    • Total dissolved solids
    • Turbidity

Additional data collected through the RIBS River and Stream Monitoring Program may include:

  • Physical habitat information
  • Evaluation of recreational use perception
  • Sediment toxicity
  • Organism tissue chemistry
  • Benthic algae composition
  • Fish presence and abundance information for small wadeable waterbodies

Lake Classification and Inventory

New York State has more than 7,600 freshwater lakes, ponds and reservoirs that are used for recreation and supply water to homes, industries, and farms. DEC staff conduct water quality sampling and evaluate these waterbodies through the LCI programs and follows the 5-year rotating basin schedule of the RIBS program.

DEC adheres to the procedures outlined in the "Standard Operating Procedure: Collection of the Lake Water Quality Samples" and the "Quality Assurance Program Plan (QAPP) for the LCI Lake Monitoring Program" to ensure uniformity of methods and data accuracy. These documents are available from NYSDEC DOW Water Quality Assurance webpage.

The following is a list of the information that is collected at the lake and collected from lake water samples in the lab.

  • Field parameters collected within the water column using a multi-parameter probe
    • Depth
    • Temperature
    • Dissolved Oxygen
    • pH
    • Specific Conductance
    • Chlorophyll A
    • Oxygen Reduction Potential (ORP)
  • Laboratory parameters collected at the surface of all lakes and from the bottom of thermally stratified lakes
    • Nutrients (phosphorus and nitrogen)
    • Chlorophyll A (surface only)
    • Alkalinity
    • True color
    • Total and dissolved organic carbon
    • Total and dissolved metals
    • Salt parameters (sodium and chloride)
    • Sulfate
    • Total dissolved solids
    • Hardness
    • Water Clarity (Secchi depth)
  • Other indicators collected at a subset of all sampled lakes
    • Aquatic plant community assessment
    • Physical habitat characteristics
    • User perception survey
    • Bathymetry
    • HABs indicators (algae, microscopy, toxins)
    • Sediment cores (diatom community assessment)
    • Benthic macroinvertebrates

Benthic Macroinvertebrates and Biomonitoring

Biological monitoring provides information on the relative health of an ecosystem since the organisms living in a waterbody serve as indicators of water quality. The types and numbers of organisms collected from polluted water differ from those collected in unpolluted water. These organisms help us determine the quality of the water and to detect changes over time. Biomonitoring is performed in rivers, streams, and lakes as part of the RIBS Program.

DEC biomonitoring adheres to the procedures outlined in the Standard Operating Procedures: Biomonitoring Field Methods. Biomonitoring Enumeration Identification, and Biomonitoring Calculations. This ensures uniformity of methods and accuracy of data when preforming biological monitoring of surface waters in New York State. View the Biological Assessment Profile (BAP) Fact Sheet (PDF) for more information on water quality assessment using biological data. Quality assurance documents are standard operating procedures are available at the NYSDEC DOW Water Quality Assurance webpage.

Groundwater Sampling

The groundwater sampling program conducts yearly comprehensive sampling and analysis of groundwater including field and physical parameters, bacteria, nutrients, inorganics, organics (including pesticides and VOCs), and radiochemicals. The program parallels the five year rotating RIBS program schedule by concentrating on approximately 1/5 of the state each year. Sampling is conducted by USGS using both public and private wells. Sampling results and data reports are available for each major basin through USGS online.

Routine Monitoring Network

Rivers and Streams

The network of "routine" sites provides annual, statewide information for a network of permanent sires to understand long-term trends in flowing waters. Currently, there are 40 Routine Network sites across New York, which are monitored annually regardless of the RIBS Monitoring cycle. Ambient water column chemistry is the primary focus of the Routine Network and is collected 4 times each year. Sampling for the Routine Network is largely conducted by DEC staff working in regional suboffices. Routine Network sires are co-located with United States Geological Survey (USGS) gage stations to facilitate loading calculations for TMDL development and other watershed planning initiatives.

Data collection from these sites in concert with other RIBS River and Stream Monitoring data, such as resident macroinvertebrate communities, have been instrumental in identifying statewide water quality trends over time. See the 2018 publication "Long-term trends in biological indicators and water quality in river and streams of New York State (1972 - 2012): Water Quality Trends in New York State"


The "routine Network" for lakes captures long term trends and includes 28 sites sampled annually by a combination of CSLAP volunteers and LCI staff. As with rivers and streams, data and analysis of long-term trends in lakes help understand changes in water quality over time.

Lake and Stream Regional Monitoring Networks

In collaboration with the United States Environmental Protection Agency (EPA) and other Northeast States, NYSDEC participates in Regional Monitoring Networks (RMNs) for Lakes and Streams. These RMNs collect biological, thermal, chemical and hydrologic data from freshwater lakes and ponds and wadeable streams. This information is used to help quantify and detect long-term changes in conditions of high-quality waterbodies. Detection of such changes can inform water quality criteria and indicator development, as well as responses to climate change impacts.

Citizen Science

Water Assessments by Volunteer Evaluators (WAVE)

Water Assessments by Volunteer Evaluators (WAVE) is a citizen-based water quality assessment developed by DEC. The purpose of WAVE is to enable citizen and community scientists to collect biological data for assessment of water quality in wadeable streams in New York State. WAVE citizen and community scientists collect benthic macroinvertebrates any time between July 1 and September 30. Participants collect riffle-dwelling benthic macroinvertebrates and preserve one or two example specimens of each macroinvertebrate type in a voucher collection.

The WAVE program collects biological data at various locations around the state and provides the RIBS Screening Network with potential site collection.

County, municipal, and not-for-profit organizations may use WAVE data to support local stream restoration and/or protection efforts. DEC is very interested in tracking these applications of the WAVE data. If you are involved or are aware of a use of the WAVE data, please contact the WAVE Coordinator.

The WAVE coordinator identifies all macroinvertebrates in the WAVE samples to the level of family and uses this data to calculate a WAVE score:

Score Data
Sample Contents WAVE Score Score Description
More than six "MOST wanted" organisms No known impact The stream is healthy in there is no observed impact to the aquatic life. The assessment is high quality and may be used for state and federal reporting purposes.
More than four "LEAST wanted" organisms Possibly Impaired The assessment serves as a red flag for sites that may deserve further investigation at the professional level. So far, we've been able to every site that was flagged as possible impaired.
Other No Conclusions Sometimes a sample does not meet either of these criteria: it doesn't have six or more "most wanted" nor four or more "least wanted". If the sampling was done properly, then the site is probably slightly impacted but not impaired. This can also happen, however, when sampling is performed incorrectly which is why the DEC records this assessment as "No Conclusion".

Become a WAVE Volunteer Today

Links to the WAVE waiver (which must be completed before participation), survey forms and FAQs can be found in the Sampling Guide (PDF) and WAVE training is also online.

Get trained in the WAVE method today from the comfort of your own home using WAVE Training video (leaves DEC website).

All WAVE announcements are sent to our DEC Delivers email list. To sign-up, visit DEC's email service webpage.

Citizen Statewide Lake Assessment Program (CSLAP)

The Citizen Statewide Lake Assessment Program (CSLAP) is a volunteer lake monitoring program directed by DEC staff in collaboration with the New York State Federation of Lake Associations (NYSFOLA). The program was adapted from successful volunteer monitoring programs in Vermont, Maine, Minnesota, and Illinois. CSLAP is one of the longest running, continuous, volunteer monitoring programs in the nation. Through this program, relationships between lake associations, academic and private research institutions, and local and state entities are built statewide.

Why do we have CSLAP?

CSLAP was established in 1985 (PDF) by DEC and NYSFOLA to pursue the program's three primary objectives:

  • Collect lake data for representative lakes throughout NYS
  • Identify lake problems an changes in water quality
  • Educate the public about lake conservation

The state Environmental Conservation Law (ECL), the legislation that established DEC and authorizes most of the programs and activities of DEC, was amended in 1988 to authorize CSLAP. The ECL 17-0305 legislation provided permanence to the program and ensured that the lake monitoring program would continue.

Who participates in CSLAP?

The lake associations and volunteers in the CSLAP program are diverse and spread throughout New York State. Lake associations collect information from public and private lakes ranging in size from small ponds to large lakes. Volunteers come from all backgrounds and include lake residents and users, teachers, lakefront communities, students, and scientists.

To find out how your lake association can participate in CSLAP, please call NYSFOLA at (315) 677-9987 or email NYSFOLA at

Data Collection

Every other week during the summer months, volunteers record lake information on field data sheets and collect water samples at the deepest part of the lake for lab analysis. A comprehensive list of sampling parameters is given in the Lake Parameters table below.

Data collected by CSLAP contribute to management efforts at the state and local level. At the state level they contribute to water quality criteria development, clean water plans, and federal 305b and 303d reports. Data are made publicly available on the DEC Info-Locator (leaves DEC website) and are used directly by lake associations, town and county governments, not-for-profits, and other state agencies.

Regular lake monitoring keeps track of existing problems, detects threats to lakes before they become a problem, and helps to evaluate lake condition patterns throughout NYS. Lake residents and trained volunteers are in a position to observe lake changes and compare them to baseline conditions. In addition to the parameters described below, CSLAP participants help with the early discovery of harmful invasive species and harmful algal blooms.

Lake Parameters
Parameter Importance
Water Temperature (°C) Water temperature affects the growth of plants and animals, the amount of oxygen in the water, and the length of the recreation season.
Water Clarity (m) Water clarity is determined with a secchi disk to measure how far down into the water column you can see.
Conductivity (µmho/cm) Conductivity measurers the amount of dissolved and suspended materials in the water, including salts and organic material. Conductivity may be related to geology or land use practices.
pH pH means water acidity. A pH value between 6 and 9 supports most types of plant and animal life.
Color (true) (platinum color units) Water color is affected by organic matter (decaying plants). The color of water can affect water clarity and impact plant growth by limiting the amount of sunlight that can pass through the water.
Phosphorus (total, mg/l) Phosphorus is an important nutrient for the growth of aquatic plants and animals in lakes. Too much phosphorus can harm aquatic life, water supplies, and recreational uses.
Nitrogen (nitrate, ammonia, and total dissolved, mg/l) Nitrogen is also an important nutrient for the growth of aquatic plants an animals in lakes. Too much nitrogen can harm aquatic life, water supplies and recreational uses.
Chlorophyll a (µg/l) Chlorophyll a is the primary pigment in green plants and estimates the amount of algae in a lake. The amount of chlorophyll a may be influenced by phosphorus and can affect the water clarity.
Calcium (mg/l) Calcium is an important nutrient for most aquatic organisms and is required for mussel shell growth. Calcium enters lakes through natural limestone deposits. Calcium concentration is related to lake conductivity and improves the lake's buffering capacity to acid rain.
Use Perception Surveys Four question survey on the Field Observations Form that capture the user's observations of the quality of the lake for recreational use.

What does NYSFOLA do?

NYSFOLA is a non-profit group of lake associations, individual citizens, park districts, lake managers, environmental organizations, and consultants dedicated to the preservation and restoration of NYS lakes and watersheds.

The goals and objectives of NYSFOLA are to protect the water resources of New York through public outreach, education, sharing information, and partnerships. NYSFOLA was founded in 1983 to address warer quality concerns and invasive species issues for concerned lake associations. The organization expanded following the launch of CSLAP and the program continues to be an important part of their mission.

NYSFOLA is involved in many activities in lake communities, and:

  • Provide annual training for CSLAP volunteers,
  • Hosts an annual lake management conference for government, academic, and lake managers,
  • Organizes regional conferences to focus on local topics,
  • Promotes educational projects and distributes Diet for a Small Lake
  • Participates in advisory groups, and
  • Represents New York State Lake Associations as an affiliate of the North American Lake Management Society (NALMS).

How to Sign Up for CSLAP

To find out how your lake association can participate in CSLAP, please call NYSFOLA at (315) 677-9987 or email NYSFOLA at Lists are generally finalized in October for the upcoming season, and fees must be submitted by early February for lakes to be included for the sampling season.

Diet for a Small Lake

NYSFOLA and DEC published Diet for a Small Lake: The Expanded Guide to New York State Lake and Watershed Management in 2009. The book is the result of several years of collaboration on lake management issues and replaces the first edition of the book published in 1990.

Diet for a Small Lake is an introduction to understanding and managing New York State lakes and provides guidance to lakeshore residents, local officials, and agencies interested in water resources. The publication contains information about the ecology, monitoring, and management of lakes and watersheds throughout New York State, drawing from the vast experience of many state lake management experts.

This publication is available in both paperback and hardcover from NYSFOLA at 1-800-796-3652.

You may download the entire book (PDF) or individual sections as listed below.

CSLAP Training Materials and Forms

Training Videos

The following series of training videos and intended to help Citizen Statewide Lake Assessment Program (CSLAP) volunteers properly collect, document, process, and ship lake samples collected as part of the CSLAP program. Videos are listed in recommended viewing order. All video links al to DEC's YouTube Videos. These videos are comprehensive, through they may not reflect minor updates and changes to the sampling protocol. The most recent sampling protocol is the best resource for updated procedures.

  • Sampling Record, Section 1--Learn how to prepare for your CSLAP sampling trip, determine your sampling location, and complete the first section of the CSLAP Sampling Record.
  • Field Observations Form--Instructions on how to complete the CSLAP Field Observations Form. This form should be completed before collecting any water quality measurements or samples.
  • Secchi Disk Sampling and Sampling Record, Section 2--Demonstration of how to measure water clarity using a Secchi disk, and how to complete the second section of the CSLAP Sampling Record.
  • Water Sample Collection and Sampling Record, Section 3--Demonstration of how to collect surface and deep water samples using a Kemmerer bottle, transfer samples into a collapsible container, and complete the third section of the CSLAP Sampling Record.
  • Finishing the Sampling Record, Section 4--Instructions on how to record weather conditions and lake comments, and complete the fourth section of the CSLAP Sampling Record Form.
  • Unfiltered Sample Processing--Instructions on to how to transfer water samples from the collapsible container into laboratory bottles for CSLAP parameters that do not require field (filtering) processing.
  • Filtered Sample Processing--Instructions on how to transfer water samples from the collapsible container into laboratory bottles for CSLAP parameters that require filtration and other field processing.
  • Shipping Samples--Demonstration of how to preserve and ship samples to the laboratories used for CSLAP for analysis.
Sampling Guidance and Other Training Materials
Resources for Lake Associations

These forms are to be used by actively participating CSLAP members conducting scheduled lake assessments assigned by DEC and NYSFOLA.

Special Studies:
Lake Ecology and Management:
General Lake Information
CSLAP Reports

CSLAP reports are completed for each participating lakes and available from DEC. Available lake reports are listed by county. Lake reports are not available for all CSLAP lakes. Reports from the most recent year are available here (leaves DEC website). Reports from 1997 through 2010 can be found on the New York State Federation of Lake Associations (NYSFOLA) website. For historical reports, please contact the DEC's Division of Water Monitoring Data Portal (leaves DEC website).

CSLAP reports summarize current and historical information about water quality biological stresses such as invasive species, and recreational perception of lakes and lake uses. Scorecards combine a lot of information into simple assessments of lake conditions, long-term trends and lake uses.

Individual and regional reports include tables and graphics to summarize key water quality and lake perception indicators, comparisons to other nearby or similar lakes, and the actual "raw" data collected by the sampling volunteers.

Water Quality Monitoring Data

DEC Data Applications

DEC Research and Publications

DEC Water quality Data Access

  • Us the Division of Water Monitoring Data Portal (leaves DEC website) to access current and historical stream and lake monitoring data in an easy-to-use map.
  • Detailed user instructions and a list of available data are provided on the info panel that appears when opening the web app.
  • Waterbody inventory and Priority Waterbody List (WI/PWL) fact sheets are now available on the DECinfo Locator *(leaves DEC website).
  • LCI data can also be accessed directly from US EPA's STORET Data Warehouse.
  • For lake and stream reports and assessments visit the Water Reporting by County webpage or the Watersheds webpage.
  • WAVE Map All of the WAVE data that have been collected since the beginning of this project are published on the online WAVE Map (leaves DEC website). For comprehensive data files, email

More about Water Quality Monitoring:

  • Contact for this Page
    Bureau of Water Assessment and Management
    Division of Water
    625 Broadway
    Albany, NY 12233-3502
    Send us an email
  • This Page Covers
  • Page applies to all NYS regions