Dataset Listing

Chester County, PA - Stream Water Chemistry, Stream Ecology - USGS (1998-2013)

USGS/CCWRA Sample based water quality data

Variables:  Discharge, Oxygen_ dissolved, pH, Specific conductance, Temperature, Calcium, Magnesium, Potassium, Sodium, Acid neutralizing capacity, Chloride, Fluoride, Silica, Sulfate, Nitrogen_ NH3, Nitrogen_ nitrate (NO3), Nitrogen_ nitrite (NO2), Phosphorus_ orthophosphate dissolved, Boron

Date Range:  (1998-2013)

Dataset Creators/Authors:  USGS; Chester County Water Resources Authority

Contact:  Kirk White,

Field Area:   Christina River Basin

Keywords & XML
  • Description

    Since 1969, the U.S. Geological Survey and the Chester County Water Resources Authority have conducted a cooperative program to evaluate stream ecology and water-quality conditions using benthic macroinvertebrates and stream-water chemistry. The Stream Conditions of Chester County Program has sampled streams every fall for over 30 years. The initial goals of the program were to evaluate stream-water quality and to further the understanding of changes in the stream ecosystem in response to urbanization. The current goals of the program are to use the data to monitor current conditions and determine trends. Data from the program have been used to help support Chester County Landscapes by providing information on biological diversity and water-quality conditions. Without monitoring it is impossible to determine if changes in land use or environmental policies and regulation are having a positive affect on water quality.

    Benthic macroinvertebrates are macroscopic animals that inhabit the bottoms of aquatic habitats. Freshwater forms include aquatic insects and other invertebrates including clams, crustaceans, snails, and worms. Factors such as streamflow, food availability, habitat, temperature, and water quality determine the makeup of the macroinvertebrate community. By sampling in similar habitats with similar physical conditions, water quality becomes the determining factor controlling community structure. Changes in abundance, diversity, species richness, and presence or absence of pollution tolerant or intolerant species can be measured and related to water quality. Trends in water quality can be determined by sampling at a single location over several years and observing changes to the community structure.

    Benthic macroinvertebrates are well suited as water-quality indicators because of their biology and availability. They are present in most aquatic systems and are relatively easy to collect. They are indicators of overall water quality and can be used to identify specific types and sources of degraded water quality. Benthic macroinvertebrates have limited mobility and cannot avoid poor water-quality conditions. They are sensitive to a wide range of environmental impacts including chemical and physical impairments.

    Biological samples collected for the Stream Conditions of Chester County Biological Monitoring Network consist of benthic macroinvertebrates collected from a riffle area of the stream. A riffle habitat is used because macroinvertebrate diversity and abundance is usually highest there.

    See more info in Comments/README

    Sample collection and identification methods remained consistent from 1970 through 1997. Benthic macroinvertebrates were collected by taking 10 rocks (45-90 millimeters in diameter) at random. Water-quality conditions were determined by analysis of the community structure and calculation of Brillouin's Diversity Index. In this index, diversity is high if a community contains many organisms that are evenly distributed; diversity is low if there are few organisms that are unevenly distributed. Brillouin's diversity index values greater than 3.0 are associated with waters receiving little or no organic wastes. Values between 1.0 and 3.0 are associated with waters receiving moderate organic wastes, and values below 1.0 are associated with waters receiving heavy organic wastes. A new sampling protocol for the Stream Conditions of Chester County Biological Monitoring Network was established in 1998 to update the program and meet the county's current needs. The new sampling protocols are based on Rapid Bioassessment Protocols (RBP) established by the U.S. Environmental Protection Agency. Samples are collected from areas of various velocities from within a riffle. Water-quality conditions are determined by analysis of the community structure and calculation of various metrics including total individuals, taxa richness, Brillouin's Diversity Index, Hilsonhoff Biotic Index, EPT taxa richness, percent EPT taxa, and percent dominate taxa. This sampling method will allow the county to compare results with those from the Pennsylvania Department of Environmental Protection, universities, local watershed associations, and other federal agencies that are using RBP's. Sampling locations were adjusted in 1998 to relocate the sampling sites to better meet the county's needs. Twenty-seven sites are samples each year. Eighteen sites are fixed integrator or reference sites. These fixed integrator sites are sampled every year. Nine sites are selected each year to assess the water quality in areas of interest to the county. The realignment of sampling sites provides better spatial coverage while increasing flexibility. The increased flexibility allows for the placement of sites to study the effects on water-quality of specific events such as road construction or residential and business developments. This makes the program capable of both short-term and long-term evaluation of stream-water quality. The Stream Conditions of Chester County Program has determined that the quality of Chester County streams has greatly improved since 1970. Current benthic macroinvertebrate communities are more diverse and contain more pollution sensitive species compared to communities sampled at the beginning of the program. Forty-five of forty-six sites analyzed between 1970 and 1986 had a statistically significant increase in diversity.
  • Keywords

    macroinvertebrate indices, stream chemistry, pennsylvania, christina river, brandywine creek,

    XML Metadata

    XML is in ISO-19115 geographic metadata format, compatible with ESRI Geoportal Server.

  • Citation for This Dataset

    USGS, Chester County Water Resources Authority, [year], accessed [date], at URL []

    Citation for This Webpage

    USGS; Chester County Water Resources Authority (2013). "CZO Dataset: Chester County, PA - Stream Water Chemistry, Stream Ecology (1998-2013) - USGS." Retrieved 19 Feb 2019, from


Chester County, PA - Stream Water Chemistry

(.php)   Data Level 0

Data Use Policy
Data Sharing Policy
  • Data Use Policy

    DRAFT v.0.4.0

    1. Use our data freely. All CZO Data Products* except those labelled Private** are released to the public and may be freely copied, distributed, edited, remixed, and built upon under the condition that you give acknowledgement as described below. Non-CZO data products — like those produced by USGS or NOAA — have their own use policies, which should be followed.

    2. Give proper citation and acknowledgement. Publications, models and data products that make use of these datasets must include proper citation and acknowledgement. Most importantly, provide a citation in a similar way as a journal article (i.e. author, title, year of publication, name of CZO “publisher”, edition or version, and URL or DOI access information. See Also include at least a brief acknowledgement such as: “Data were provided by the NSF-supported Southern Sierra Critical Zone Observatory” (replace with the appropriate observatory name).

    3. Let us know how you will use the data. The dataset creators would appreciate hearing of any plans to use the dataset. Consider consultation or collaboration with dataset creators.

    *CZO Data Products.  Defined as a data collected with any monetary or logistical support from a CZO.

    **Private. Most private data will be released to the public within 1-2 years, with some exceptionally challenging datasets up to 4 years. To inquire about potential earlier use, please contact us.

  • Data Sharing Policy

    DRAFT v.0.2.5

    All CZO investigators and collaborators who receive material or logistical support from a CZO agree to:

    1. Share data privately within 1 year. CZO investigators and collaborators agree to provide CZO Data Products* — including data files and metadata for raw, quality controlled and/or derived data — to CZO data managers within one year of collection of samples, in situ or experimental data. By default, data values will be held in a Private CZO Repository**, but metadata will be made public and will provide full attribution to the Dataset Creators†.

    2. Release data to public within 2 years. CZO Dataset Creators will be encouraged after one year to release data for public access. Dataset Creators may chose to publish or release data sooner.

    3. Request, in writing, data privacy up to 4 years. CZO PIs will review short written applications to extend data privacy beyond 2 years and up to 4 years from time of collection. Extensions beyond 3 years should not be the norm, and will be granted only for compelling cases.

    4. Consult with creators of private CZO datasets prior to use. In order to enable the collaborative vision of the CZO program, data in private CZO repositories will be available to other investigators and collaborators within that CZO. Releasing or publishing any derivative of such private data without explicit consent from the dataset creators will be considered a serious scientific ethics violation.

    * CZO Data Products. Defined as data collected with any monetary or logistical support from a CZO. Logistical support includes the use of any CZO sensors, sampling infrastructure, equipment, vehicles, or labor from a supported investigator, student or staff person. CZO Data Products can acknowledge multiple additional sources of support.

    ** Private CZO Repository. Defined as a password-protected directory on each CZO’s data server. Files will be accessible by all investigators and collaborators within the given CZO and logins will be maintained by that local CZO’s data managers. Although data values will not be accessible by the public or ingested into any central data system (i.e. CUAHSI HIS), metadata will be fully discoverable by the public. This provides the dual benefit of giving attribution and credit to dataset creators and the CZO in general, while maintaining protection of intellectual property while publications are pending.

    † Dataset Creators. Defined as the people who are responsible for designing, collecting, analyzing and providing quality assurance for a dataset. The creators of a dataset are analogous to the authors of a publication, and datasets should be cited in an analogous manner following the emerging international guidelines described at

CZO Field Areas