&EPA
United States
Environmental Protection
Agency
Office of Water
4304
EPA822-B-00-019
December 2000
Ambient Water Quality
Criteria Recommendations
Information Supporting the Development
of State and Tribal Nutrient Criteria
Rivers and Streams in
Nutrient Ecoregion IX
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EPA -822-B-00-019
AMBIENT WATER QUALITY CRITERIA RECOMMENDATIONS
INFORMATION SUPPORTING THE DEVELOPMENT OF STATE AND TRIBAL
NUTRIENT CRITERIA
FOR
RIVERS AND STREAMS IN NUTRIENT ECOREGION IX
Southeastern Temperate Forested Plains and Hills
including all or parts of the States of
Maryland, Pennsylvania, Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama,
Mississippi, Tennessee, Kentucky, Indiana, Illinois, Iowa, Missouri, Kansas, Oklahoma,
Arkansas, Louisiana, Texas
and the authorized Tribes within the Ecoregion
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF WATER
OFFICE OF SCIENCE AND TECHNOLOGY
HEALTH AND ECOLOGICAL CRITERIA DIVISION
WASHINGTON, D.C.
DECEMBER 2000
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FOREWORD
This document presents EPA's nutrient criteria for Rivers and Streams in Nutrient
Ecoregion IX. These criteria provide EPA's recommendations to States and authorized Tribes
for use in establishing their water quality standards consistent with section 303(c) of CWA.
Under section 303(c) of the CWA, States and authorized Tribes have the primary responsibility
for adopting water quality standards as State or Tribal law or regulation. The standards must
contain scientifically defensible water quality criteria that are protective of designated uses.
EPA's recommended section 304(a) criteria are not laws or regulations - they are guidance that
States and Tribes may use as a starting point for the criteria for their water quality standards.
The term "water quality criteria" is used in two sections of the Clean Water Act, Section
304(a)(l) and Section 303(c)(2). The term has a different impact in each section. In Section 304,
the term represents a scientific assessment of ecological and human health effects that EPA
recommends to States and authorized Tribes for establishing water quality standards that
ultimately provide a basis for controlling discharges or releases of pollutants or related
parameters. Ambient water quality criteria associated with specific waterbody uses when
adopted as State or Tribal water quality standards under Section 303 define the level of a
pollutant (or, in the case of nutrients, a condition) necessary to protect designated uses in ambient
waters. Quantified water quality criteria contained within State or Tribal water quality standards
are essential to a water quality-based approach to pollution control. Whether expressed as
numeric criteria or quantified translations of narrative criteria within State or Tribal water quality
standards, quantified criteria serve as a critical basis for assessing attainment of designated uses
and measuring progress toward meeting the water quality goals of the Clean Water Act.
EPA is developing section 304(a) water quality criteria for nutrients because States and
Tribes consistently identify excessive levels of nutrients as a major reason why as much as half of
the surface waters surveyed in this country do not meet water quality objectives, such as full
support of aquatic life. EPA expects to develop nutrient criteria that cover four major types of
waterbodies - lakes and reservoirs, rivers and streams, estuarine and coastal areas, and wetlands -
across fourteen major ecoregions of the United States. EPA's section 304(a) criteria are
intended to provide for the protection and propagation of aquatic life and recreation. To support
the development of nutrient criteria, EPA is publishing Technical Guidance Manuals that describe
a process for assessing nutrient conditions in the four waterbody types.
EPA's section 304(a) water quality criteria for nutrients provide numeric water quality
criteria, as well as procedures by which to translate narrative criteria within State or Tribal water
quality standards. In the case of nutrients, EPA section 304(a) criteria establish values for causal
variables (e.g., total nitrogen and total phosphorus) and response variables (e.g., turbidity and
chlorophyll a). EPA believes that State and Tribal water quality standards need to include
quantified endpoints for causal and response variables to provide sufficient protection of uses and
to maintain downstream uses. These quantified endpoints will most often be expressed as
numeric water quality criteria or as procedures to translate a State or Tribal narrative criterion
into a quantified endpoint.
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EPA will work with States and authorized Tribes as they adopt water quality criteria for
nutrients into their water quality standards. EPA recognizes that States and authorized Tribes
require flexibility in adopting numeric nutrient criteria into State and Tribal water quality
standards. States and authorized Tribes have several options available to them. EPA
recommends the following approaches, in order of preference:
(1) Wherever possible, develop nutrient criteria that fully reflect localized conditions and
protect specific designated uses using the process described in EPA's Technical Guidance
Manuals for nutrient criteria development. Such criteria may be expressed either as
numeric criteria or as procedures to translate a State or Tribal narrative criterion into a
quantified endpoint in State or Tribal water quality standards.
(2) Adopt EPA's section 304(a) water quality criteria for nutrients, either as numeric
criteria or as procedures to translate a State or Tribal narrative nutrient criterion into a
quantified endpoint.
(3) Develop nutrient criteria protective of designated uses using other scientifically
defensible methods and appropriate water quality data.
Geoffrey H. Grubbs, Director
Office of Science and Technology
in
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DISCLAIMER
This document provides technical guidance and recommendations to States, authorized
Tribes, and other authorized jurisdictions to develop water quality criteria and water quality
standards under the Clean Water Act (CWA) to protect against the adverse effects of nutrient
overenrichment. Under the CWA, States and authorized Tribes are to establish water quality
criteria to protect designated uses. State and Tribal decision-makers retain the discretion to adopt
approaches on a case-by-case basis that differ from this guidance when appropriate and
scientifically defensible. While this document contains EPA's scientific recommendations
regarding ambient concentrations of nutrients that protect aquatic resource quality, it does not
substitute for the CWA or EPA regulations; nor is it a regulation itself. Thus it cannot impose
legally binding requirements on EPA, States, authorized Tribes, or the regulated community, and
it might not apply to a particular situation or circumstance. EPA may change this guidance in the
future.
IV
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EXECUTIVE SUMMARY
Nutrient Program Goals
EPA developed the National Strategy for the Development of Regional Nutrient Criteria
(National Strategy) in June 1998. The strategy presents EPA's intentions to develop technical
guidance manuals for four types of waters (lakes and reservoirs, rivers and streams, estuaries and
coastal waters, and wetlands) and produce section 304(a) criteria for specific nutrient ecoregions
by 2000. In addition, the Agency formed Regional Technical Assistance Groups (RTAGs) which
include State and Tribal representatives working to develop more refined and more localized
nutrient criteria based on approaches described in the waterbody guidance manuals. This
document presents EPA's current recommended criteria for total phosphorus, total nitrogen,
chlorophyll a, and turbidity for rivers and streams in Nutrient Ecoregion IX (Southeastern
Temperate Forested Plains and Hills) which were derived using the procedures described in the
Rivers and Streams Nutrient Criteria Technical Guidance Manual (2000b).
EPA's ecoregional nutrient criteria are intended to address cultural eutrophication— the
adverse effects of excess nutrient inputs. The criteria are empirically derived to represent
conditions of surface waters that are minimally impacted by human activities and protective of
aquatic life and recreational uses. The information contained in this document represent starting
points for States and Tribes to develop (with assistance from EPA) more refined nutrient criteria.
In developing these criteria recommendations, EPA followed a process which included, to
the extent they were readily available, the following elements critical to criterion derivation:
• Historical and recent nutrient data in Nutrient Ecoregion IX.
Data sets from Legacy STORET, NASQAN, NAWQA, Auburn University, and EPA
Regions 3, 5 and 7 were used to assess nutrient conditions from 1990 to 1998.
• Reference sites/reference conditions in Nutrient Ecoregion IX.
Reference conditions presented are based on 25th percentiles of all nutrient data including a
comparison of reference condition for the aggregate ecoregion versus the sub ecoregions.
States and Tribes are urged to determine their own reference sites for rivers and streams
within the ecoregion at different geographic scales and to compare them to EPA's
reference conditions.
• Models employed for prediction or validation.
EPA did not identify any specific models used in the ecoregion to develop nutrient
criteria. States and Tribes are encouraged to identify and apply appropriate models to
support nutrient criteria development.
• RTAG expert review and consensus.
EPA recommends that when States and Tribes prepare their nutrient criteria, they obtain
the expert review and consent of the RTAG.
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• Downstream effects of criteria.
EPA encourages the RTAG to assess the potential effects of the proposed criteria on
downstream water quality and uses.
In addition, EPA followed specific QA/QC procedures during data collection and
analysis: All data were reviewed for duplications. All data are from ambient waters that were not
located directly outside a permitted discharger. The following States indicated that their data
were sampled and analyzed using either Standard methods or EPA approved methods: Florida,
Georgia, Illinois, Indiana, Iowa, Maryland, Missouri, North Carolina, South Carolina, and
Tennessee.
The following tables contain a summary of Aggregate and level III ecoregion values for
TN, TP, water column chl a, and turbidity:
BASED ON 25th PERCENTILE ONLY
Nutrient Parameters
Total phosphorus (jug/L)
Total nitrogen (mg/L)
Chlorophyll a (jug/L) (Spectrophotometric
method)
Periphyton Chlorophyll a (mg/m2)
Turbidity (FTU)
Aggregate Nutrient Ecoregion IX
Reference Conditions
36.56
0.69
0.93
20.35
5.7
For subecoregions, 29,33, 35, 37, 40, 45, 64, 65, 71, 72, and 74, the ranges of nutrient parameter
reference conditions are:
BASED ON 25th PERCENTILE ONLY
Nutrient Parameters
Total phosphorus (jug/L)
Total nitrogen (mg/L)
Chlorophyll a (jug/L)
Periphyton Chlorophyll a (mg/m2)
Turbidity (FTU)
Range of Level III Subecoregions
Reference Conditions
22.5 - 100.00
0.07- 1.0
0.05 - 5.74
3.13 -20.35
3.15 - 13.5
VI
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NOTICE OF DOCUMENT AVAILABILITY
This document is available electronically to the public through the INTERNET at:
(http://www.epa.gov/OST/standards/nutrient.html). Requests for hard copies of the document
should be made to EPA's National Service Center for Environmental Publications (NSCEP),
11029 Kenwood Road, Cincinnati, OH 45242 or (513) 489-8190, or toll free (800) 490-9198.
Please refer to EPA document number EPA-822-B-00-019.
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ACKNOWLEDGMENTS
The authors thankfully acknowledge the contributions of the following State and Federal
reviewers: EPA Regions 1, 2, 3, 4, 5, 6 and 7; the States of Maryland, Pennsylvania, Virginia,
North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Tennessee, Kentucky,
Indiana, Illinois, Iowa, Missouri, Kansas, Oklahoma, Arkansas, Louisiana and Texas; the Tribes
within the Ecoregion; EPA Headquarters personnel from the Office of Wetlands, Oceans and
Watersheds, Office of Wastewater Management, Office of General Counsel, Office of Research
and Development, and the Office of Science and Technology. EPA also acknowledges the
external peer review efforts of Eugene Welch (University of Washington), Robert Carlson (Kent
State University), Steve Heiskary (Minnesota Pollution Control Agency), Greg Denton and
Sherry Wang (Tennessee Department of Environment and Conservation), and Gerhard Kuhn
(U.S. Geological Survey).
Vlll
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LISTS OF TABLES AND FIGURES
Figures
Figure 1 Aggregate Ecoregion IX 7
Figure 2 Aggregate Ecoregion IX with level III ecoregions shown 8
Figure 3 Sampling locations within each level III ecoregion 13
Figure 4a Illustration of data reduction process for stream data 25
Figure 4b Illustration of reference condition calculation 26
Tables
Table 1
Table 2
Rivers and Streams records for Aggregate Ecoregion IX- Southeastern Temperate
Forested Plains and Hills 14
Reference conditions for Aggregate Ecoregion IX streams 17
Table 3a-k Reference conditions for level III ecoregion streams 18
IX
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TABLE OF CONTENTS
Foreword ii
Disclaimer iv
Executive Summary v
Notice of Document Availability vii
Acknowledgments viii
List of Tables and Figures ix
Table of Contents x
1.0 Introduction 1
2.0 Best Use of this Information 4
3.0 Area Covered by This Document (waterbody type and ecoregion) 6
3.1 Description of Aggregate Ecoregion IX- Southeastern Temperate Forested Plains
and Hills 6
3.2 Geographical Boundaries of Aggregate Ecoregion IX 7
3.3 Level III Ecoregions within Aggregate Ecoregion IX 8
4.0 Data Review for Rivers and Streams in Aggregate Ecoregion IX 10
4.1 Data Sources 11
4.2 Historical Data from Aggregate Ecoregion IX (TP, TN, Chi a, Turbidity) 11
4.3 QA/QC of Data Sources 11
4.4 Data for All Rivers/Streams within Aggregate Ecoregion IX 11
4.5 Statistical Analysis of Data 11
4.6 Classification of River/Stream Type 16
4.7. Summary of Data Reduction Methods 16
5.0 Reference Sites and Conditions in Aggregate Ecoregion IX 28
6.0 Models Used to Predict or Verify Response Parameters 28
7.0 Framework for Refining Recommended Nutrient Criteria for Rivers and Streams in
Aggregate Ecoregion IX 28
7.1 Example Worksheet for Developing Aggregate Ecoregion and Subecoregion Nutrient
Criteria 29
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7.2 Tables of Refined Nutrient Water Quality Criteria for Aggregate Ecoregion IX and
Level III Subecoregions 30
7.3 Setting Seasonal Criteria 31
7.4 When Data/Reference Conditions Are Lacking 32
7.5 Site-Specific Criteria Development 32
8.0 Literature Cited 32
9.0 Appendices 33
XI
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1.0 INTRODUCTION
Background
Nutrients are essential to the health and diversity of our surface waters. However, in
excessive amounts, nutrients cause hypereutrophication, which results in overgrowth of plant life
and decline of the biological community. Excessive nutrients can also result in potential human
health risks, such as the growth of harmful algal blooms - most recently manifested in the
Pfiesteria outbreaks of the Gulf and East Coasts. Chronic nutrient over enrichment of a
waterbody can lead to the following consequences: low dissolved oxygen, fish kills, algal blooms,
overabundance of macrophytes, likely increased sediment accumulation rates, and species shifts of
both flora and fauna.
Historically, National Water Quality Inventories have repeatedly shown that nutrients are a
major cause of ambient water quality use impairments. EPA's 1996 National Water Quality
Inventory report identifies excessive nutrients as the leading cause of impairment in lakes and the
second leading cause of impairment in rivers (behind siltation). In addition, nutrients were the
second leading cause of impairments reported by the States in their 1998 lists of impaired waters.
Where use impairment is documented, nutrients contribute roughly 25-50% of the impairment
nationally. The Clean Water Act establishes a national goal to achieve, wherever attainable, water
quality which provides for the protection and propagation offish, shellfish, and wildlife and
recreation in and on the water. In adopting water quality standards, States and Tribes designate
uses for their waters in consideration of the Clean Water Act goals, and establish water quality
criteria that contain sufficient parameters to protect those uses. To date, EPA has not published
information and recommendations under section 304(a) for nutrients to assist States and Tribes in
establishing numeric nutrient criteria to protect uses when adopting water quality standards.
In 1995, EPA gathered a set of national experts and asked the experts how to best deal
with the national nutrient problem. The experts recommended that the Agency not develop single
criteria values for phosphorus or nitrogen applicable to all water bodies and regions of the
country. Rather, the experts recommended that EPA put a premium on regionalization, develop
guidance (assessment tools and control measures) for specific waterbodies and ecological regions
across the country, and use reference conditions (conditions that reflect pristine or minimally
impacted waters) as a basis for developing nutrient criteria.
With these suggestions as starting points, EPA developed the National Strategy for the
Development of Regional Nutrient Criteria (National Strategy), published in June 1998. This
strategy presented EPA's intentions to develop technical guidance manuals for four types of
waters (lakes and reservoirs, rivers and streams, estuaries and coastal waters, and wetlands) and,
thereafter, to publish section 304(a) criteria recommendations for specific nutrient ecoregions.
Technical guidance manuals for lakes/reservoirs and rivers/streams were published in April 2000
and July 2000, respectively. The technical guidance manual for estuaries/coastal waters will be
published in spring 2000 and the draft wetlands technical guidance manual will be published by
December 2001. Each manual presents EPA's recommended approach for developing nutrient
criteria values for a specific waterbody type. In addition, EPA is committed to working with
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States and Tribes to develop more refined and more localized nutrient criteria based on
approaches described in the waterbody guidance manuals and this document.
Overview of the Nutrient Criteria Development Process
For each Nutrient Ecoregion, EPA developed a set of recommendations for two causal
variables (total nitrogen and total phosphorus) and two early indicator response variables
(chlorophyll a and some measure of turbidity). Other indicators such as dissolved oxygen and
macrophyte growth or speciation, and other fauna and flora changes are also deemed useful.
However, the first four are considered to be the best suited for protecting designated uses.
The technical guidance manuals describe a process for developing nutrient criteria that
involves consideration of five factors. The first of these is the Regional Technical Assistance
Group (RTAG), which is a body of qualified regional specialists able to objectively evaluate all of
the available evidence and select the value(s) appropriate to nutrient control in the water bodies of
concern. These specialists may come from such disciplines as limnology, biology, natural
resources management— especially water resource management, chemistry, and ecology. The
RTAG evaluates and recommends appropriate classification techniques for criteria determination,
usually physical within an ecoregional construct.
The second factor is the historical information available to establish a perspective of the
resource base. This is usually data and anecdotal information available within the past ten-twenty
five years. This information gives evidence about the background and enrichment trend of the
resource.
The third factor is the present reference condition. A selection of reference sites chosen to
represent the least culturally impacted waters of the class existing at the present time. The data
from these sites is combined and a value from the distribution of these observations is selected to
represent the reference condition, or best attainable, most natural condition of the resource base at
this time.
A fourth factor often employed is theoretical or empirical models of the historical and
reference condition data to better understand the condition of the resource.
The RTAG comprehensively evaluates the other three elements to propose a candidate
criterion (initially one each for TP, TN, chl a, and some measure of turbidity).
The last and final element of the criteria development process is the assessment by the
RTAG of the likely downstream effects of the criterion. Will there be a negative, positive, or
neutral effect on the downstream waterbody? If the RTAG judges that a negative effect is likely,
then the proposed State/Tribal water quality criteria should be revised to ameliorate the potential
for any adverse downstream effects.
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While States and authorized Tribes would not necessarily need to incorporate all five
elements into their water quality criteria setting process (e.g., modeling may be significant in only
some instances), the best assurance of a representative and effective criterion for nutrient
management decision making is the balanced incorporation of all five elements, or at least all
elements except modeling.
Because some parts of the country have naturally higher soil and parent material
enrichment, and different precipitation regimes, the application of the criterion development
process has to be adjusted by region. Therefore, an ecoregional approach was chosen to develop
nutrient criteria appropriate to each of the different geographical and climatological areas of the
country. Initially, the continental U.S. was divided into 14 separate ecoregions of similar
geographical characteristics. Ecoregions are defined as regions of relative homogeneity in
ecological systems; they depict areas within which the mosaic of ecosystem components (biotic
and abiotic as well as terrestrial and aquatic) is different than adjacent areas in a holistic sense.
Geographic phenomena such as soils, vegetation, climate, geology, land cover, and physiology
that are associated with spatial differences in the quantity and quality of ecosystem components
are relatively similar within each ecoregion.
The Nutrient ecoregions are aggregates of U.S. EPA=s hierarchal level III ecoregions. As
such, they are more generalized and less defined than level III ecoregions. EPA determined that
setting ecoregional criteria for the large scale aggregates is not without its drawbacks - variability
is high due to the lumping of many waterbody classes, seasons, and years worth of multipurpose
data over a large geographic area. For these reasons, the Agency recommends that States and
Tribes develop nutrient criteria at the level III ecoregional scale and at the waterbody class scale
where those data are readily available. Data analyses and recommendations on both the large
aggregate ecoregion scale as well as more refined scales (level III ecoregions and waterbody
classes), where data were available to make such assessments, are presented for comparison
purposes and completeness of analysis.
Relationship of Nutrient Criteria to Biological Criteria
Biological criteria are quantitative expressions of the desired condition of the aquatic
community. Such criteria can be based on an aggregation of data from sites that represent the
least-impacted and attainable condition for a particular waterbody type in an ecoregion,
subecoregion, or watershed. EPA's nutrient criteria recommendations and biological criteria
recommendations have many similarities in the basic approach to their development and data
requirements. Both are empirically derived from statistical analysis of field collected data and
expert evaluation of current reference conditions and historical information. Both utilize direct
measurements from the environment to integrate the effects of complex processes that vary
according to type and location of waterbody. The resulting criteria recommendations, in both
cases, are efficient and holistic indicators of water quality necessary to protect uses.
States and authorized Tribes can develop and apply nutrient criteria and biological criteria
in tandem, with each providing important and useful information to interpret both the nutrient
enrichment levels and the biological condition of sampled waterbodies. For example, using the
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same reference sites for both types of criteria can lead to efficiencies in both sample design and
data analysis. In one effort, environmental managers can obtain information to support
assessment of biological and nutrient condition, either through evaluating existing data sets or
through designing and conducting a common sampling program. The traditional biological
criteria variables of benthic invertebrate and fish sampling can be readily incorporated to
supplement a nutrient assessment. To demonstrate the effectiveness of this tandem approach,
EPA has initiated pilot projects in both freshwater and marine environments to investigate the
relationship between nutrient overenrichment and apparent declines in diversity indices of benthic
invertebrates and fish.
2.0 BEST USE OF THIS INFORMATION
EPA recommendations published under section 304(a) of the CWA serve several
purposes, including providing guidance to States and Tribes in adopting water quality standards
for nutrients that ultimately provide a basis for controlling discharges or releases of pollutants.
The recommendations also provide guidance to EPA when promulgating Federal water quality
standards under section 303(c) when such action is necessary. Other uses include identification of
overenrichment problems, management planning, project evaluation, and determination of status
and trends of water resources.
State water quality inventories and listings of impaired waters consistently rank nutrient
overenrichment as a top contributor to use impairments. EPA's water quality standards
regulations at 40 CFR § 131.11 (a) require States and Tribes to adopt criteria that contain
sufficient parameters and constituents to protect the designated uses of their waters. In addition,
States and Tribes need quantifiable targets for nutrients in their standards to assess attainment of
uses, develop water quality-based permit limits and source control plans, and establish targets for
total maximum daily loads (TMDLs).
EPA expects States and Tribes to address nutrient overenrichment in their water quality
standards, and to build on existing State and Tribal initiated efforts where possible. States and
Tribes can address nutrient overenrichment through establishment of numerical criteria or through
use of new or existing narrative criteria statements (e.g., free from excess nutrients that cause or
contribute to undesirable or nuisance aquatic life or produce adverse physiological response in
humans, animals, or plants). In the case of narrative criteria, EPA expects that States and Tribes
establish procedures to quantitatively translate these statements for both assessment and source
control purposes.
The intent of developing ecoregional nutrient criteria is to represent conditions of surface
waters that are minimally impacted by human activities and thus protect against the adverse
effects of nutrient overenrichment from cultural eutrophication. EPA's recommended process for
developing such criteria includes physical classification of waterbodies, determination of current
reference conditions, evaluation of historical data and other information (such as published
literature), use of models to simulate physical and ecological processes or determine empirical
relationships among causal and response variables (if necessary), expert judgement, and
evaluation of downstream effects. To the extent allowed by the information available, EPA has
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used elements of this process to produce the information contained in this document. The values
for both causal (total nitrogen, total phosphorus) and biological and physical response
(chlorophyll a, turbidity) variables represent a set of starting points for States and Tribes to use in
establishing their own criteria in standards to protect uses.
In its water quality standards regulations, EPA recommends that States and Tribes
establish numerical criteria based on section 304(a) guidance, section 304(a) guidance modified to
reflect site-specific conditions, or other scientifically defensible methods. For many pollutants,
such as toxic chemicals, EPA expects that section 304(a) guidance will provide an appropriate
level of protection without further modification in most cases. EPA has also published methods
for modifying 304(a) criteria on a site-specific basis, such as the water effect ratio, where site-
specific conditions warrant modification to achieve the intended level of protection. For nutrients,
however, EPA expects that, in most cases, it will be necessary for States and authorized Tribes to
identify with greater precision the nutrient levels that protect aquatic life and recreational uses.
This can be achieved through development of criteria modified to reflect conditions at a smaller
geographic scale than an ecoregion such as a subecoregion, the State or Tribe level, or specific
class of waterbodies. Criteria refinement can occur by grouping data or performing data analyses
at these smaller geographic scales. Refinement can also occur through further consideration of
other elements of criteria development, such as published literature or models.
The values presented in this document generally represent nutrient levels that protect
against the adverse effects of nutrient overenrichment and are based on information available to
the Agency at the time of this publication. However, States and Tribes should critically evaluate
this information in light of the specific designated uses that need to be protected. For example,
more sensitive uses may require more stringent values as criteria to ensure adequate protection.
On the other hand, overly stringent levels of protection against the adverse effects of cultural
eutrophication may actually fall below levels that represent the natural load of nutrients for certain
waterbodies. In cases such as these, the level of nutrients specified may not be sufficient to
support a productive fishery. In the criteria derivation process, it is important to distinguish
between the natural load associated with a specific waterbody and current reference conditions,
using historical data and expert judgement. These elements of the nutrient criteria derivation
process are best addressed by States and Tribes with access to information and local expertise.
Therefore, EPA strongly encourages States and Tribes to use the information contained in this
document and to develop more refined criteria according to the methods described in EPA's
technical guidance manuals for specific waterbody types.
To assist in the process of further refinement of nutrient criteria, EPA has established ten
Regional Technical Advisory Groups (experts from EPA Regional Offices and States/Tribes). In
the process of refining criteria, States and authorized Tribes need to provide documentation of
data and analyses, along with a defensible rationale, for any new or revised nutrient criteria they
submit to EPA for review and approval. As part of EPA's review of State and Tribal standards,
EPA intends to seek assurance from the RTAG that proposed criteria are sufficient to protect
uses.
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In the process of using the information and recommendations contained in this document,
as well as additional information, to develop numerical criteria or procedures to translate narrative
criteria, EPA encourages States and Tribes to:
• Address both chemical causal variables and early indicator response variables. Causal
variables are necessary to provide sufficient protection of uses before impairment occurs
and to maintain downstream uses. Early response variables are necessary to provide
warning signs of possible impairment and to integrate the effects of variable and
potentially unmeasured nutrient loads.
• Include variables that can be measured to determine if standards are met, and variables
that can be related to the ultimate sources of excess nutrients.
• Identify appropriate periods of duration (i.e., how long) and frequency (i.e., how often) of
occurrence in addition to magnitude (i.e., how much). EPA does not recommend
identifying nutrient concentrations that must be met at all times, rather a seasonal or
annual averaging period (e.g., based on weekly measurements) is considered appropriate.
However, these seasonal or annual central tendency measures should apply each season or
each year, except under the most extraordinary of conditions (e.g., a 100 year flood).
3.0 AREA COVERED BY THIS DOCUMENT
The following sections provide a general description of the aggregate ecoregion and its
geographical boundaries. Descriptions of the level III ecoregions contained within the aggregate
ecoregion are also provided.
3.1 Description of Aggregate Ecoregion IX - Southeastern Temperate Forested Plains
and Hills
Region IX is composed of irregular plains and hills. Originally, the Southeastern
Temperate Forested Plains and Hills (IX) was mostly forested in contrast to the South Central
Cultivated Great Plains (V); areas of savannah and grassland also occurred. Today, Region IX is
a mosaic of forest, cropland, and pasture. The Southeastern Temperate Forested Plains and Hills
(IX) is not as arable as the South Central Cultivated Great Plains (V) or the Corn Belt and
Northern Great Plains (VI). However, there is much more cropland than in the more rugged
Central and Eastern Forested Uplands (XI). Lateritic soils are common and are a contrast to the
soils of the surrounding regions. Areas of depleted soils are found in Region IX. Major poultry
and aquaculture operations occur locally in the Southeastern Temperate Forested Plains and Hills
(IX). Stream quality in the Southeastern Temperate Forested Plains and Hills (IX) has been
significantly affected by urban, suburban, and industrial development as well as by poultry,
livestock, silviculture, and aquaculture operations. Downstream of sewage treatment plants,
poultry farms, and hog operations, nutrient levels and fecal coliform bacteria concentrations can
be very high. There are a large number of intensive chicken, turkey, and hog operations in Region
IX; effluent from intensive livestock production poses a substantial eutrophication threat to
surface waters. In contrast, streams draining relatively undisturbed and forested watersheds have
low median concentrations of fecal coliform bacteria, sulfate, dissolved solids, and phosphorus.
Silviculture, agriculture, and urban development have impacted suspended sediment levels in
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streams especially where soils are highly erodible. Coal mining has degraded water quality and
affected aquatic biota in several areas including southern Iowa, northern Missouri, and eastern
Pennsylvania. Excessive PCB and DDT concentrations have been detected in the Schuylkill River
of Pennsylvania and have led to advisories against local fish consumption.
3.2 Geographical Boundaries of Aggregate Ecoregion IX
Ecoregion IX is an expansive region encompassing parts of twenty States (Figure 1). The
region's northeastern border is the southeastern corner of Pennsylvania. The region runs
southward through the States of Maryland, Virginia, North Carolina, South Carolina, Georgia and
Florida. Only the northwestern corner of Florida is included in the region. West of Georgia, the
region includes parts of Alabama, Mississippi, Louisiana and Texas. The region runs north up
through the middle of the country to include parts of Oklahoma, Arkansas, Kansas, Missouri,
Tennessee, Kentucky, Iowa, Illinois and Indiana. The northwestern boundary of the region is
approximately described by the southeastern corner of Iowa, the southern half of Illinois and the
southwestern third of Indiana.
Aggregate Nutrient Ecoregion 9
Ecoregion ID
D 29
D 33
I 35
a 37
D 40
D 45
• 64
• 65
D 71
• 72
H 74
Figure 1. Aggregate Ecoregion IX
-------
3.3 Level III Ecoregions Within Aggregate Ecoregion IX
There are eleven Level III ecoregions contained within Aggregate Ecoregion IX (Figure 2). The
following provides brief descriptions of the climate, vegetation cover, topography, and other
ecological information pertaining to these subecoregions.
29. Central Oklahoma/Texas Plains
The Central Oklahoma/Texas Plains ecoregion is a transition area between the once prairie, now
winter wheat growing regions to the west, and the forested low mountains of eastern Oklahoma.
The region does not possess the arability and suitability for crops such as corn and soybeans that
are common in the Central Irregular Plains to the northeast. Transitional "cross-timbers" (little
bluestem grassland with scattered blackjack oak and post oak trees) is the native vegetation, and
presently rangeland and pastureland comprise the predominant land cover. Oil extraction has
been a major activity in this region for over eighty years.
33. East Central Texas Plains
Also called the Claypan Area, this region of irregular plains was originally covered by a post oak
savanna vegetation, in contrast to the more open prairie-type regions to the north, south and west
and the piney woods to the east. The bulk of this region is now used for pasture and range.
Aggregate Nutrient Ecoregion 9
Figure 2. Aggregate Ecoregion IX with level III ecoregions shown.
-------
35. South Central Plains
Locally termed the "piney woods", this region of mostly irregular plains was once blanketed by
oak-hickory-pine forests, but is now predominantly in loblolly and shortleaf pine. Only about one
sixth of the region is in cropland, whereas about two thirds is in forests and woodland. Lumber
and pulpwood production are major economic activities
37. Arkansas Valley
A region of mostly forested valleys and ridges, the physiography of the Arkansas Valley is much
less irregular than that of the Boston Mountains to the north and the Ouachita Mountains to the
south, but is more irregular than the ecological regions to the west and east. About one fourth of
the region is grazed and roughly one tenth is cropland. In the Arkansas Valley, even streams that
have been relatively unimpacted by human activities have considerably lower dissolved oxygen
levels, and hence support different biological communities, than those of most of the adjacent
regions.
40. Central Irregular Plains
The Central Irregular Plains has a mix of land use types and tends to be topographically more
irregular than the Western Corn Belt Plains to the north, where most of the land is in crops;
however, the region is less irregular and less forest covered than the ecoregions to the south and
east. The potential natural vegetation of this ecological region is a grassland/forest mosaic with
wider forested strips along the streams compared to the region to the north. The mix of land use
activities in the Central Irregular Plains also includes mining operations of high-sulfur bituminous
coal. The disturbance of these coal strata in southern Iowa and northern Missouri has degraded
water quality and affected aquatic biota.
45. Piedmont
Considered the nonmountainous portion of the old Appalachians Highland by physiographers, the
northeast-southwest trending Piedmont ecoregion comprises a transitional area between the
mostly mountainous ecoregions of the Appalachians to the northwest and the flat coastal plain to
the southeast. Once largely cultivated, much of this region has reverted to pine and hardwood
woodlands.
64. Northern Piedmont
The Northern Piedmont is transitional region of low rounded hills, irregular plains, and open
valleys in contrast to the low mountains of ecoregions to the north and west and the flat coastal
plains of the ecoregion to the east. Potential natural vegetation here was predominantly
Appalachian oak forest as compared to the mostly oak-hickory-pine forests of the Piedmont
ecoregion to the southwest.
65. Southeastern Plains
These irregular plains have a mosaic of cropland, pasture, woodland, and forest. Natural
vegetation is mostly oak-hickory-pine and Southern mixed forest. The Cretaceous or Tertiary-
age sands, silts, and clays of the region contrast geologically to the older igneous and
metamorphic rocks of the Piedmont, and the older limestone, chert, and shale found in the Interior
Plateau. Streams in this area are relatively low-gradient and sandy-bottomed.
-------
71. Interior Plateau
The Interior Plateau is a diverse ecoregion extending from southern Indiana and Ohio to northern
Alabama. Rock types are distinctly different from the coastal plain sands and alluvial deposits to
the west, and elevations are lower than the Appalachian ecoregions to the east. Mississippian to
Ordovician-age limestone, chert, sandstone, siltstone and shale compose the
landforms of open hills, irregular plains, and tablelands. The natural vegetation is primarily oak-
hickory forest, with some areas of bluestem prairie and cedar glades. The region has a diverse
fish fauna.
72. Interior River Lowland
The Interior River Lowland is made up of many wide, flat-bottomed terraced valleys, forested
valley walls, and dissected glacial till plains. In contrast to the generally rolling to slightly
irregular plains in adjacent ecological regions to the north, east and west, where most of the land
is cultivated for corn and soybeans, a little less than half of this area is in cropland, about 30
percent is in pasture, and the remainder is in pasture.
74. Mississippi Valley Loess Plains
This ecoregion stretches from near the Ohio River in western Kentucky to Louisiana. It consists
primarily of irregular plains, with oak-hickory and oak-hickory-pine natural vegetation. Thick
loess tends to be the distinguishing characteristic. With flatter topography than the Southeastern
Plains ecoregion to the east, streams tend to have less gradient and more silty substrates.
Agriculture is the dominant land use in the Kentucky and Tennessee portion of the region, while
in Mississippi there is a mosaic of forest and cropland.
Suggested ecoregional subdivisions or adjustments.
EPA recommends that the RTAG evaluate the adequacy of EPA nutrient ecoregional and
subecoregional boundaries and refine them as needed to reflect local conditions.
4.0 DATA REVIEW FOR RIVERS AND STREAMS IN AGGREGATE ECOREGION
IX
The following section describes the nutrient data EPA has collected and analyzed for this
Ecoregion, including an assessment of data quantity and quality. The data tables present the data
for each causal parameter— total phosphorus and total nitrogen (both reported and calculated
from TKN and nitrite/nitrate), and the primary response variables— some measure of turbidity
and chlorophyll a. These are the parameters which EPA considers essential to nutrient assessment
because the first two are the main causative agents of enrichment and the two response variables
are the early indicators of system enrichment for most of the surface waters (see Chapter 3 of the
Rivers and Streams Nutrient Criteria Technical Guidance Manual [U.S. EPA, 2000b] for a
complete discussion on choosing causal and response variables.)
10
-------
4.1 Data Sources
Data sets from Legacy STORET, NASQAN, NAWQA, Auburn University, and EPA
Regions 3, 5, and were used to assess nutrient conditions froml990 to!999. EPA recommends
that the RTAGs identify additional data sources that can be used to supplement the data sets listed
above. In addition, the RTAGs may utilize published literature values to support quantitative and
qualitative analyses.
4.2 Historical Data from Aggregate Ecoregion IX (TP, TN, Chi a and Turbidity)
EPA recommends that States/Tribes assess long-term trends observed over the past 50
years. This information may be obtained from scientific literature or documentation of historical
trends. To gain additional perspective on more recent trends, it is recommended that States and
Tribes assess nutrient trends over the last 10 years (e.g., what do seasonal trends indicate?)
4.3 QA/QC of Data Sources
An initial quality screen of data was conducted using the rules presented in Appendix C.
Data remaining after screening for duplications and other QA measures (.e.g., poor or unreported
analytical records, sampling errors or omissions, stations associated with outfalls, storm water
sewers, hazardous waste sites) is the data used in statistical analyses.
The following States indicated that their data were sampled and analyzed using either
Standard methods or EPA approved methods: Florida, Georgia, Illinois, Iowa, Indiana,
Maryland, Missouri, North Carolina, South Carolina, Tennessee. Other States in Ecoregion IX
did not provide information at this time.
4.4 Data for All Rivers and Streams Within Aggregate Ecoregion IX
Figure 3 shows the location of the sampling stations within each subecoregion. Table 1
presents all data records for all parameters for Aggregate Ecoregion IX and subecoregions within
the Aggregate Ecoregion.
4.5 Statistical Analysis of Data
EPA's Technical Guidance Manual for Developing Nutrient Criteria for Rivers and
Streams describes two ways of establishing a reference condition. One method is to choose the
upper 25th percentile (75th percentile) of a reference population of streams. This is the preferred
method to establish a reference condition. The 75th percentile was chosen by EPA since it is likely
associated with minimally impacted conditions, will be protective of designated uses, and provides
management flexibility. When reference streams are not identified, the second method is to
determine the lower 25th percentile of the population of all streams within a region. The 25th
percentile of the entire population was chosen by EPA to represent a surrogate for an actual
reference population. Data analyses to date indicate that the lower 25th percentile from an entire
population roughly approximates the 75th percentile for a reference population (see case studies
11
-------
for Minnesota lakes in the Lakes and Reservoirs Nutrient Criteria Technical Guidance Document
[U.S. EPA, 2000a], the case study for Tennessee streams in the Rivers and Streams Nutrient
Criteria Technical Guidance Document [U.S. EPA, 2000b], and the letter from Tennessee
Department of Environment and Conservation to Geoffrey Grubbs [TNDEC, 2000]). New York
State has also presented evidence that the 25th percentile and the 75th percentile compare well
based on user perceptions of water resources (NYSDEC, 2000).
12
-------
Nutrient 9
River Stations
Level III Ecoregions
| 29 40
CD 33 45
35 64
71
72
74
37
US
100 0 100 200 Miles
Figure 3 Map of sampling locations within each level III ecoregion.
13
-------
Table 1. Rivers and Streams records for Aggregate Ecoregion IX - Southeastern Temperate Forested Plains and
Hills
# of Stream names
# of Stream Stations
Key Nutrient Parameters
(listed below)
- # of records for Turbidity
(all methods)
- # of records for
Chlorophyll a (all methods)
+ Periphyton
- # of records for Total
Kjeldahl Nitrogen (TKN)
- # of records for Nitrate +
Nitrite (NO2 + NO3)
- # of records for Total
Nitrogen (TN)
- # of records for Total
Phosphorus (TP)
Total # of records for key
nutrient parameters
Aggregate
Ecoregion
IX
3,278
115,125
16,756
116,104
117,925
13,749
164,145
543,804
Sub
ecoR 29
160
256
1,631
698
2,173
1,334
351
2,412
8,599
Sub
ecoR 33
44
73
203
521
856
469
80
981
3,110
Sub
ecoR 35
286
465
8,137
889
6,808
9,184
317
10,173
35,508
Sub
ecoR 37
56
93
2,226
2
1,215
2,469
123
2,421
8,456
Sub
ecoR 40
220
445
3,569
229
2,522
3,015
390
5,305
15,030
Sub
ecoR 45
639
1,298
36,404
858
31,205
29,898
1,014
42,948
142,327
14
-------
Table 1 (continued). Rivers and Streams records for Aggregate Ecoregion IX -
Southeastern Temperate Forested Plains and Hills
1
# of Stream names
# of Stream Stations
Key Nutrient Parameters (listed
below)
- # of records for
Turbidity (all methods)
- # of records for
Chlorophyll a (all
methods) + Periphyton
- # of records for Total
Kjeldahl Nitrogen (TKN)
- # of records for Nitrate +
Nitrite (NO2 + NO3)
- # of records for Total
Nitrogen (TN)
- # of records for Total
Phosphorus (TP)
Total # of records for key
nutrient parameters
Sub
ecoR 64
284
880
8,325
3,397
14,572
6,407
2,396
17,541
52,638
Sub
ecoR 65
1,001
1,870
40,234
9,336
41,353
37,963
6,382
52,744
180,012
Sub
ecoR 71
213
429
3,574
606
3,709
6,640
206
6,454
21,189
Sub
ecoR 72
309
550
9,772
194
7,801
13,823
2,424
16,108
50,122
Sub
ecoR 74
103
162
1,050
24
3,890
6,723
66
7,058
18,811
15
-------
Definitions used in filling Table 1
1. # of records refers to the total count of observations for that
parameter over the entire decade (1990-1999) for that particular
aggregate or subecoregion. These are counts for all seasons over
that decade.
2. # of stream stations refers to the total number of river and
stream stations within the aggregate or subecoregion from which
nutrient data was collected. Since streams and rivers can cross
ecoregional boundaries, it is important to note that only those
portions of a river or stream (and data associated with those
stations) that exist within the ecoregion are included within this
table.
Tables 2 and 3a-k present potential reference conditions for both the aggregate ecoregion
and the subecoregions using both methods. However, the reference stream column is left blank
because EPA does not have reference data and anticipates that States/Tribes will provide
information on reference streams. Appendix A provides a complete presentation of all descriptive
statistics for both the aggregate ecoregion and the level III subecoregion.
4.6. Classification of River/Stream Type
It is anticipated that assessing the data by stream type will further reduce the variability in
the data analysis. There were no readily available classification data in the National datasets used
to develop these criteria. States and Tribes are strongly encouraged to classify their streams
before developing a final criterion.
4.7. Summary of Data Reduction Methods
All descriptive statistics were calculated using the medians for each stream within
ecoregion IX, for which data existed. For example, if one stream had 300 observations for
phosphorus over the decade or one year's time, one median resulted. Each median from each
stream was then used in calculating the percentiles for phosphorus for the aggregate nutrient
ecoregion/subecoregion (level III ecoregion) by season and year (Figure 4a & b).
16
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Table 2. Reference conditions for aggregate ecoregion IX streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP («g/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a («g/L) -F
Chlorophyll a («g/L) -S
Chlorophyll a («g/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
1,609
1,671
NA
274
2,104
476
1,143
97
71
235
70
6
Reported values
Min
0
0
0
0.24
0
0.175
0.475
0.713
0.225
0
0
11
Max
4.825
9.78
15.60
12.4
2,400
162.5
148
164.5
36.73
78.9
93.92
62
25 Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.3
0.125
0.425
0.692
36.56
7.02
5.7
3.53
2.25
0.93
0.53
20.35
Reference Streams * *
P75 - all seasons
P25:
P75:
**
F
S
T
NA
25th percentile of all data
75th percentile of all data
as determined by the Regional Technical Assistance Groups (RTAGs)
Median for all seasons' 25th percentiles. E.g. this value was calculated from
four seasons' 25th percentiles. If the seasonal 25th percentile (P25) TP values
are - spring lOwg/L, summer 15ug/L, fall \2ugfL, and winter 5ug/L, the
median value of all seasons P25 will be 1 Iwg/L.
N = largest value reported for a decade / Season.
TN calculated is based on the sum of TKN + NO2+NO3
TN reported is actual TN value reported in the database for one sample.
Chlorophyll a measured by Fluorometric method with acid correction.
Chlorophyll a measured by Spectrophotometric method with acid correction.
Chlorophyll a b c measured by Trichromatic method.
Not Applicable
calculated medians from less than 3 seasons' data.
Table(s) 3a.-k. present the potential reference conditions for rivers and streams in the
Level III subecoregions within the Aggregate Ecoregion. The footnotes for Table 2 apply to
tables 3a-k.
17
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Table 3a. Reference conditions for level III ecoregion 29 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP («g/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a («g/L) -F
Chlorophyll a («g/L) -S
Chlorophyll a («g/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
93 W
78 W
NA
20
100 W
6
53 F
17
1 z
32
-
-
Reported values
Min
0.05
0.01
0.06
0.39
2.5
2.738
0.9
2
13
0.25
-
-
Max
2.058
4.7
6.758
3.228
1,332.5
27.4
95.5
164.5
13
33.8
-
-
25 Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.4
0.078
0.478
0.68
37.5
3.713
8.825
9.125
13 zz
1.238
-
-
Reference Streams * *
P75 - all seasons
Table 3b. Reference conditions for level III ecoregion 33 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP (Mg/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a (Mg/L) -F
Chlorophyll a (Mg/L) -S
Chlorophyll a (Mg/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
30
21
NA
3
28
1 z
7
0
0
24
-
-
Reported values
Min
0.285
0.04
0.325
0.935
45
0.5
4.3
-
-
0.25
-
-
Max
2.48
7.582
10.062
5.688
1,880
0.5
90.25
-
-
21.15
-
-
25l Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.543
0.138
0.681
0.935
100
0.5 zz
10.9
-
-
0.733
-
-
Reference Streams **
P75 - all seasons
18
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Table 3c. Reference conditions for level III ecoregion 35 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP (Mg/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a («g/L) -F
Chlorophyll a (wg/L) -S
Chlorophyll a (wg/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
124
140
NA
19
164
82
57 S/W
8 z
0
44
-
2z
Reported values
Min
0.05
0.005
0.055
0.33
2.5
2.863
2
3.5
-
0.25
-
3.13
Max
3.213
6.245
9.458
3.738
1900
106.5
69.375
127
-
34.213
-
5.85
25th Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.44
0.067
0.507
0.385
50
9.513
6.938
13
-
0.566
-
3.13 zz
Reference Streams **
P75 - all seasons
Table 3d. Reference conditions for level III ecoregion 37 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP (wg/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a (wg/L) -F
Chlorophyll a (wg/L) -S
Chlorophyll a (wg/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
26
37
NA
8
39
23
17 S/W
7
0
1 z
-
-
Reported values
Min
0.23
0.015
0.245
0.55
5
3.15
5.15
2
-
4.5
-
-
Max
2.315
6.479
8.794
1.75
1410
71.5
53.5
61.5
-
4.5
-
-
25l Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.53
0.075
0.605
0.683
42.5
6.95
13.5
15.25
--
4.5 zz
-
-
Reference Streams **
P75 - all seasons
19
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Table 3e. Reference conditions for level III ecoregion 40 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP (Mg/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a (ugfL) -F
Chlorophyll a (Mg/L) -S
Chlorophyll a (Mg/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
81
137
NA
31
146
53
78
19
12
16
-
—
Reported values
Min
0.184
0.003
0.187
0.28
10
7.825
2.2
4.9
0.65
2.025
-
-
Max
4.175
9.203
13.378
6.225
2090
96.575
73.625
115.25
24.8
22.55
-
-
25th Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.625
0.23
0.855
0.712
92.5
15.5
12.25
10.5
2.75 zz
5.488
-
—
Reference Streams **
P75 - all seasons
Table 3f. Reference conditions for level III ecoregion 45 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP (Mg/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a (Mg/L) -F
Chlorophyll a (Mg/L) -S
Chlorophyll a (Mg/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
338
327
NA
18
436
35
356
10
33
11
-
-
Reported values
Min
0.025
0.003
0.028
0.238
0
2.25
1.125
1.9
1
1.8
-
-
Max
3.1
8.813
11.913
2.57
1425
35.45
108
26.05
36.725
25
-
-
25l Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.234
0.177
0.411
0.615
30
5.713
7.488
5.95
3.3
3.493
-
-
Reference Streams **
P75 - all seasons
20
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Table 3g. Reference conditions for level III ecoregion 64 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP (Hg/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a (wg/L) -F
Chlorophyll a (wg/L) -S
Chlorophyll a (wg/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
125
77
NA
76
181
33
46 F
2
0
18
-
6F
Reported values
Min
0.05
0.225
0.275
0.56
1.25
1.05
0.625
4.4
-
0.443
-
17
Max
2.843
8.362
11.205
12.4
1545
23
13.088
5.425
-
8.41
-
62
25 Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.3
0.995
1.295
2.225
40
2.825
3.15
4.4
-
1.205
-
20.35
Reference Streams **
P75 - all seasons
Table 3h. Reference conditions for level III ecoregion 65 streams.
Parameter
TKN (mg/L)
NO2 + NO3(mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP («g/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a («g/L) -F
Chlorophyll a (wg/L) -S
Chlorophyll a («g/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
554
518
NA
65
650
173
426
21 S
14
74
-
L_
Reported values
Min
0
0
0
0.33
0
0.25
0.475
1.875
0.25
0
-
-
Max
4.138
5.077
9.215
2.938
1735
100
88.75
88
8.8
65.552
-
-
25 Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.3
0.095
0.395
0.618
22.5
6.2
4.338
6.55
1.438
0.049
-
-
Reference Streams **
P75 - all seasons
21
-------
Table 3i. Reference conditions for level III ecoregion 71 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP (Hg/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a (wg/L) -F
Chlorophyll a (wg/L) -S
Chlorophyll a (wg/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
65
109
NA
10
117
47
22
21 S
9
14
-
-
Reported values
Min
0.05
0.008
0.058
0.625
2.5
0.875
1.8
0.813
2.6
0.25
-
-
Max
2.045
5.373
7.418
4.35
1280
104.138
44.075
15.75
15.4
7.75
-
-
25th Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.284
0.345
0.629
0.8
30
6.975
7.3
1.325
3.85
1.5
-
-
Reference Streams **
P75 - all seasons
Table 3j. Reference conditions for level III ecoregion 72 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP («g/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a («g/L) -F
Chlorophyll a (wg/L) -S
Chlorophyll a (wg/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
154
173
NA
21
183
5
118
3
2 z
1
-
L
Reported values
Min
0.025
0.003
0.028
0.47
1.25
13.5
1.15
29.75
1.5
5.74
-
-
Max
4.318
8.625
12.943
7.088
1,600
39
126.75
37
6.55
5.74
-
-
25l Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.539
0.215
0.754
1.669
83.125
15
6.263
29.75
1.5 zz
5.74
-
-
Reference Streams **
P75 - all seasons
22
-------
Table 3k. Reference conditions for level III ecoregion 74 streams.
Parameter
TKN (mg/L)
NO2 + NO3 (mg/L)
TN (mg/L) - calculated
TN (mg/L) - reported
TP (Mg/L)
Turbidity (NTU)
Turbidity (FTU)
Turbidity (JCU)
Chlorophyll a (wg/L) -F
Chlorophyll a (Mg/L) -S
Chlorophyll a (Mg/L) -T
Periphyton Chi a (mg/m2)
No. of
Streams
N++
31
65
NA
3
70
18
11
5
2 Fz
0
-
—
Reported values
Min
0.137
0.022
0.159
0.6
2.5
6.3
3.25
1.775
2
-
-
-
Max
2.875
2.515
5.39
1.25
1,162.5
91.75
78.375
18.25
2.1
-
-
-
25 Percentiles based
on all seasons data for
the Decade
P25-all seasons
0.364
0.14
0.504
0.6
75
16.25
13.5
7.55
2 Tl
-
-
—
Reference Streams **
P75 - all seasons
23
-------
Definitions used in filling Tables 2 and 3 - Reference Condition tables
Definitions used in filling Tables 2 and 3 - Reference Condition tables
1. Number of Streams in Table 2 refers to the largest number of streams and rivers for which data existed
for a given season within an aggregate nutrient ecoregion.
2. Number of Streams in Table 3 refers to the number of streams and rivers for which data existed for the
summer months since summer is generally when the greatest amount of nutrient sampling is conducted. If
another season greatly predominates, notification is made (s=spring, f=fall, w=winter).
3. Medians. All values (min, max, and 25th percentiles) included in the table are based on waterbody
medians. All data for a particular parameter within a stream for the decade were reduced to one median for
that stream. This prevents over-representation of individual waterbodies with a great deal of data versus those
with fewer data points within the statistical analysis.
4. 25th percentile for all seasons is calculated by taking the median of the 4 seasonal 25th percentiles. If a
season is missing, the median was calculated with 3 seasons of data. If less than 3 seasons were used to
derive the median, the entry is flagged (z).
5. A 25th percentile for a season is best derived with data from a minimum of 4 streams/season. However,
this table provides 25th percentiles that were derived with less than 4 streams/season in order to retain all
information for all seasons. In calculating the 25th percentile for a season with less than 4 stream medians,
the statistical program automatically used the minimum value within the less-than-4 population. If less than
4 streams were used in developing a seasonal quartile and or all-seasons median, the entry is flagged (zz).
24
-------
Observations for All Rivers/Streams
Ecoregion
Winter
Spring
Data Reduced
to
Median Value
for each
River/Stream
by
Season
Summer
Fall
Figure 4a. Illustration of data reduction process for stream data.
25
-------
Select 25th Percentile
from Distribution
of Median
Values
25th
25%
25%
25%
Winter
Spring
Summer
Fall
Calculate Median
Value of the
25th Percentiles
for the Four Seasons
TP
TN
TKN
NO2+NO3
Chi a
Turbidity
25%
25%
Half values
Below Median
Half values
Above Median
1
25%
Season A
1
25%
Season B
1
25%
Season C
1
25%
Season D
Median = Reference Condition for the Ecoregion
Figure 4b. Illustration of reference condition calculation.
26
-------
Preferred Data Choices and Recommendations When Data Are Missing
1. Where data are missing or are very low in total records for a given parameter, use 25th
percentiles for parameters within an adjacent, similar subecoregion within the same aggregate
nutrient ecoregion or when a similar subecoregion can not be determined, use the the 25th
percentile for the Aggregate ecoregion or consider the lowest 25th percentile from a subecoregion
(level III) within the aggregate nutrient ecoregion. The rationale being that without data, one may
assume that the subecoregion in question may be as sensitive as the most sensitive subecoregion
within the aggregate.
2. TN calculated: When reported Total Nitrogen (TN) median values are lacking or very low in
comparison to TKN and Nitrate/Nitrite-N values, the medians for TKN and nitrite/nitrate-N were
added, resulting in a calculated TN value. The number of samples (N) for calculated TN is not
filled in since it is represented by two subsamples of data: TKN and nitrite/nitrate-N. Therefore,
N/A is placed in this box.
3. TN reported: This is the median based on reported values for TN from the database.
4. Chlorophyll a. Medians based on all methods are reported, however, the acid corrected
medians are preferred to the uncorrected medians. In developing a reference condition from a
particular method, it is recommended that the method with the most observations be used.
Fluorometric and Spectrophotometric are preferred over all other methods. However, when no
data exist for Fluorometric and Spectrophotometric methods, Trichromatic values may be used.
Data from the variance techniques are not interchangeable.
5. Periphyton: Where periphyton data exist, record them separately For periphyton-dominated
streams, a measure of periphyton chlorophyll is a more appropriate response variable than
planktonic chlorophyll a. See Table 4, p. 101 of the Rivers and Streams Nutrient Technical
Guidance Manual (U. S. EPA, 2000b) for values of periphyton and planktonic chlorophyll a
related to eutrophy in streams.
6. Secchi depth: The 75th percentile is reported for Secchi depth since this is the only variable
for which the value of the parameter increases with greater clarity. (For lakes and reservoirs
only.)
7. Turbidity units: All turbidity units from all methods are reported. FTUs and NTUs are
preferred over JCUs. If FTUs and NTUs do not exist, use JCUs. These units are not
interchangeable. Turbidity is chosen as a response variable in streams since it can be an indicator
of increasing algal biomass due to nutrient enrichment. See pages 32 -33 of the Rivers and
Streams Nutrient Technical Guidance Manual for a discussion of turbidity and correlations with
algal growth.
8. Lack of data: A dash (-) represents missing, inadequate, or inconclusive data. A zero (0) is
reported if the reported median for a parameter is 0 or if the component value is below detection.
27
-------
5.0 REFERENCE SITES AND CONDITIONS IN AGGREGATE ECOREGION IX
Reference conditions represent the natural, least impacted conditions or what is
considered to be the most attainable conditions. This section compares the different reference
conditions determined from the two methods and establishes which reference condition is most
appropriate.
A priori determination of reference sites. The preferred method for establishing reference
condition is to choose the upper percentile of an a priori population of reference streams. States
and Tribes are encouraged to identify reference conditions based on this method.
Statistical determination of reference conditions (25th percentile of entire database.) See Tables 2
and 3a-k in section 4.0.
RTAG discussion and rationale for selection of reference sites and conditions in Ecoregion IX.
The RTAG should compare the results derived from the two methods described above and
present a rationale for the final selection of reference sites.
6.0 MODELS USED TO PREDICT OR VERIFY RESPONSE PARAMETERS
The RTAG is encouraged to identify and apply relevant models to support nutrient criteria
development. The following are three scenarios under which models may be used to derive
criteria or support criteria development.
• Models for predicting correlations between causal and response variables
• Models used to verify reference conditions based on percentiles
• Regression models used to predict reference conditions in impacted areas
7.0 FRAMEWORK FOR REFINING RECOMMENDED NUTRIENT CRITERIA
FOR RIVERS AND STREAMS IN AGGREGATE ECOREGION IX
Information on each of the following six weight of evidence factors is important to refine the
criteria presented in this document. All elements should be addressed in developing criteria, as is
expressed in our nutrient criteria technical guidance manuals. It is our expectation that EPA
Regions, States, and Tribes (as RTAGs) will consider these elements as States/Tribes develop
their criteria. This section should be viewed as a work sheet (sections are left blank for this
purpose) to assist in the refinement of nutrient criteria. If many of these elements are ultimately
unaddressed, EPA may rely on the proposed reference conditions presented in Tables 3a-k and
other literature and information readily available to the HQ nutrient team to develop nutrient
water quality recommendations for this ecoregion.
28
-------
7.1 Example Worksheet for Developing Aggregate Ecoregion and Subecoregion
Nutrient Criteria
• Literature sources
Historical data and trends
Reference condition
Models
RTAG expert review and consensus
Downstream effects
29
-------
7.2 Tables of Refined Nutrient Water Quality Criteria for Aggregate Ecoregion IX and
Level III Subecoregions for TP, TN, Chi a, Turbidity (where sufficient data exist)
Aggregate Ecoregion IX- Southeastern
Temperate Forested Hills and Plains
Total Phosphorus (|ig/L)
Total Nitrogen (mg/L)
Chlorophyll a (|ig/L or mg/m2))
Turbidity (NTU or other units)
Other (Index; other parameter such as DO)
Proposed Criterion
Literature sources
Historical data and trends
Reference condition
Models
RTAG expert review and consensus
30
-------
Downstream effects
Ecoregion #29 Central Oklahoma/Texas
Plains
Total Phosphorus (|ig/L)
Total Nitrogen (mg/L)
Chlorophyll a (|ig/L or mg/m2))
Turbidity (NTU or other units)
Other (Index; other parameter such as DO)
Proposed Criterion
7.3 Setting Seasonal Criteria
The recommendations presented in this document are based in part on medians of all the
25th percentile seasonal data (decadal), and as such are reflective of all seasons and not one
particular season or year. It is recommended that States and Tribes monitor in all seasons to best
assess compliance with the resulting criterion. States/Tribes may choose to develop criteria which
reflect each particular season or a given year when there is significant variability between
seasons/years or designated uses that are specifically tied to one or more seasons of the year (e.g.,
recreation, fishing). Using the tables in Appendix A and B, one can set reference conditions based
on a particular season or year and then develop a criterion based on each individual season.
Obviously, this option is season-specific and would also require increased monitoring within each
season to assess compliance.
-------
7.4 When Data/Reference Conditions are Lacking
When data are unavailable to develop a reference condition for a particular parameter(s)
within a subecoregion, EPA recommends one of three options: 1. Use data from a similar
neighboring subecoregion. E.g., If data are few or nonexistent for the northern cascades, consider
using the data and reference condition developed for the cascades; or 2. Use the 25th perecentiles
for the Aggregate ecoregion or 3. Consider using the lowest of the yearly medians for that
parameter calculated for all the subecoregions within the Aggregate Ecoregion.
7.5 Site-specific Criteria Development
Criteria may be refined in a number of ways. The best way to refine criteria is to follow
the critical elements of criteria development as well as to refer to the Rivers and Streams Nutrient
Criteria Technical Guidance Manual (U.S. EPA, 2000b).
The Technical Guidance Manual presents sections on each of the following factors to
consider in setting criteria
- refinements to ecoregions (Section 2.3)
- classification of waterbodies (Chapter 2)
- setting seasonal criteria to reflect major seasonal climate differences and accounting for
significant or cyclical precipitation events (high flow/low flow conditions) (Chapter 4).
8.0 LITERATURE CITED
NYSDEC (New York State Department of Environment and Conservation). 2000.
Memorandum from Scott Kishbaugh to Jay Bloomfield, September 26, 2000, regarding
reference lakes for nutrient criteria.
TNDEC (Tennessee Department of Environment and Conservation). 2000. Letter to
Geoff Grubbs, October 5, 2000, containing comments on draft nutrient criteria
recommendations.
U.S. EPA. 2000a. Nutrient Criteria Technical Guidance Manual: Lakes and Reservoirs,
U.S. Environmental Protection Agency, Washington, DC. EPA-822-BOO-001.
U.S. EPA. 2000b. Nutrient Criteria Technical Guidance Manual: Rivers and Streams,
U.S. Environmental Protection Agency, Washington, DC. EPA-822-BOO-002.
32
-------
9.0 APPENDICES
A. Descriptive Statistics Data Tables for Aggregate Ecoregion
B. Descriptive Statistics Data Tables for Level III Subecoregions within Aggregate Ecoregion
C. Quality Control/Quality Assurance Rules
33
-------
APPENDIX A
Descriptive Statistics Data Tables for Aggregate Ecoregion
-------
SEASON
FALL
SPRING
SUMMER
WINTER
54
37
71
Ifl
MEAN
fl.D3
fl.E7
ID.7
4-4D
HIM
• E5D
• DDD
• bE5
• EDD
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Fluo_ug_L_Hedian
MAX
3b-35
37-ID
IS. ID
13- ID
STDDEV
fl.11
1E-1
3- IE
STDERR
1-ES
1-35
1-53
D-1E
CV
114
11
1ED
fll
P5
D-4D
D-E5
I.DD
D.ED
PE5
LflD
LID
MEDIAN
4-ID
4-5D
7-DD
3-4D
P75
fl.flD
11-7
lE-fl
7-ID
P15
El-fl
E4-5
Eb.fl
13-1
SEASON
FALL
SPRING
SUMMER
WINTER
MEAN
4D
tfl
tD
D-7fl
MIN
3-4D
LID
1-bD
• 775
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Phyto_C_F_ug_L_Med
MAX
3-4D
1L45
1-bD
D-7fl
STDDEV
b-75
STDERR
4-7fl
CV
1D1
P5
3-4D
LID
1-bD
D-7fl
PE5
3-4D
L-1D
LbD
MEDIAN
4D
tfl
tD
D-7fl
D-7fl
P75
3-4D
11.5
1-bD
D-7fl
P15
3-4D
11.5
1-bD
D-7fl
SEASON
FALL
SPRING
SUMMER
WINTER
N
Ifl7
EDb
E35
17fl
MEAN
D3
54
44
3-13
MIN
• DDD
• DDD
• DDD
• DDD
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Phyto_Spec_A_ug_L_Median
MAX
7fl.bD
Ifl.SE
71-ED
34-flD
STDDEV
1-71
11.1
11.5
4-flD
STDERR
D-7E
D-77
D-75
D-3b
CV
IbE
17D
154
153
P5
D-E5
D-DD
D.DD
D.DD
PE5
D.ID
D-17
LD3
D-E5
MEDIAN
E-
3-
3-
L
fl5
3fl
4fl
P75
7-5D
1-DD
3-4fl
P15
11.fl
E5-D
E5-4
1E-D
SEASON
FALL
SPRING
SUMMER
WINTER
MEAN
D-D3
4-37
D-DE
MIN
• DE5
4-37
• DEI
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Phyto_Spec_U_ug_L_Median
MAX
D-D3
4-37
D-DE
STDDEV
STDERR
CV
P5
D-D3
4-37
D.DE
PE5
D-D3
4-37
D.DE
MEDIAN
D-D3
4-37
D.DE
P75
D-D3
4-37
D.DE
P15
D-D3
4-37
D.DE
SEASON
FALL
SPRING
MEAN
MIN
4fl 1-75 -DDD
44 LEE -DDD
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Tric_U_ug_L_Median
MAX
17-7fl
15-Db
STDDEV
Ifl.E
17-E
STDERR
E-b3
E-51
CV
Ifl7
Iflb
P5
D.DD
D.DD
PE5
LDb
LbD
MEDIAN
L11
3-47
P75
ID-5
7-11
P15
43-4
4D-fl
-------
SUMMER
WINTER
7D
SD
1E.Q
E.DI
• DDD
• DDD
1E-7fl
Ib.lD
3-7b
E-3fl
D-53
Ibb
IfiD
D.DD
D.DD
D.DD
D.DD
3-14
l-Dfl
13-D
E-34
IE.5
SEASON
FALL
SPRING
SUMMER
WINTER
MEAN
D-4D
D-31
D-7D
D.DS
MIN
• 4DD
• EDD
• 7DD
• DSD
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chlb_Phyto_C_F_ug_L_Med
MAX
D-4D
D-43
D-7D
D.DS
STDDEV
D-lb
STDERR
D-11
CV
51
PS
D-4D
D.ED
D-7D
D.DS
PES
D-4D
D.ED
D-7D
D.DS
MEDIAN
D-4D
D-31
D-7D
D.DS
P7S
D-4D
D-43
D-7D
D.DS
PIS
D-4D
D-43
D-7D
D.DS
SEASON
FALL
SPRING
SUMMER
WINTER
MEAN
D-E4
MIN
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chlb_Phyto_Spec_ug_L_Median
MAX
D-E4
STDDEV
STDERR
CV
PS
D-E4
PES
D-E4
MEDIAN
D-E4
P7S
D-E4
PIS
D-E4
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter DIP_ug_L_Median
SEASON
FALL
SPRING
SUMMER
WINTER
N
E17
IfiD
E3D
17D
MEAN
17S
b4 • 1
bS-1
b3 • 3
MIN
• DDD
• DDD
• DDD
• DDD
MAX
IbDD.DD
fllE-DD
13D-DD
1DDD-DD
STDDEV
74E
US
IDE
IDfl
STDERR
SD-4
fi.Sfi
b-7D
fl.EI
CV
4E3
IfiD
1S4
171
PS
S.DD
S.DD
S.DD
S.DD
PES
lb-3
1D-D
IE. 5
13- fl
MEDIAN
SD-D
3D-D
37-3
3S-D
P7S
US
7D-D
fll-S
7S-D
PIS
Sbfl
EE4
Ifl3
EDD
SEASON
FALL
SPRING
SUMMER
WINTER
N
1437
1417
1S71
1E4D
MEAN
7-73
fl.57
b.fl3
1D-S
MIN
• DDD
1-flD
• DDD
E-1D
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter DO_mg_L_Median
MAX
17.flfl
13-flD
13-SD
14-7D
STDDEV
l.fl?
1-bl
l.b?
1-bD
STDERR
D.DS
D-D4
D-D4
D.DS
CV
E4
11
E4
IS
PS
4-3D
S-fl3
3-SD
7-73
PES
b-75
tD
DD
Lb4
MEDIAN
fi.DD
fl. tD
7-ID
ID.5
P7S
fl.75
LSD
7-fl3
11.b
PIS
ID-4
11.E
LID
13-D
-------
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter NOE_N03_mg_L_Median
ID
SEASON
FALL
SPRING
SUMMER
WINTER
15E7
15E1
137fl
MEAN
D-74
D.71
D-73
D.fl3
HIM
• DDD
• DDD
• DDD
• DDD
MAX
1D-DD
1-flD
1-D3
STDDEV
1-3D
1.1S
LED
1-Efl
STDERR
D-D3
D-D3
D-D3
D-D3
CV
175
Ibl
IbS
155
P5
D-Dl
D-D3
D-Dl
D-D3
PES
D.DI
D-14
D.IE
D-14
MEDIAN
D-E7
D-3E
D.EI
D-3b
P75
D-74
D-73
D-74
D-1D
PIS
3.ED
MS
3-11
3-41
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Org_P_ug_L_Hedian
11
SEASON
FALL
SPRING
SUMMER
WINTER
N
IS
D
IS
D
MEAN
7D-4
SE-4
MIN
EE-S
b-77
MAX
Iflfl.
us.
• 3D
.44
STDDEV
SD.
Efl.
• E
• S
STDERR
13- D
7-37
CV
71
54
PS
EE-S
b-77
PES
37- b
E7-4
MEDIAN P7S PIS
51.1 fl4-l Iflfl
4fl-7 bb-3 US
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Orthophosphate_T_as_P_ug_L_Med
IE
SEASON
FALL
SPRING
SUMMER
WINTER
N
1DD
1D3
1D3
1D1
MEAN
117
flE-1
1D4
77-b
MIN
5-DD
5-DD
5-DD
S-DD
MAX
IbDD-DD
1D15-DD
13D7-SD
fllS-DD
STDDEV
Ebl
IbE
EDE
113
STDERR
Eb-1
15-1
11.1
11-3
CV
EE3
IIS
114
PS
S.DD
S.DD
S.DD
S.DD
PES
17.
17.
it.
ED-D
MEDIAN
4D-D
37- 5
41-3
4D-D
P7S
Ifl.fl
flD-D
1D3
1DD
PIS
41D
E3fl
31D
EES
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter TKN_mg_L_Median
13
SEASON
FALL
SPRING
SUMMER
WINTER
N
14D4
14SE
IbDI
1317
MEAN
D-bE
D. tD
D-b4
D-S3
MIN
• DDD
• DDD
• DDD
• DDD
MAX
S-4D
S.DD
4-3D
4-bS
STDDEV
D-SS
D-S3
D-4fl
D-43
STDERR
D-Dl
D.DI
D.DI
D.DI
cv
ai
aa
74
flD
PS
D-13
D.IE
D-IS
D.IE
PES
D-3D
D-3D
D-3S
D-3D
MEDIAN
D-SD
D-4fl
D-S3
D-44
P7S
D-7fl
D-73
D-fll
D. tS
PIS
LSD
1-47
1.45
LED
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter TN_mg_L_Median
14
SEASON
FALL
SPRING
E13
ED4
MEAN
l.fl?
E-DE
MIN
• IflD
• 3DD
MAX
1E-SD
11.DD
STDDEV
E-Db
1-lfl
STDERR
D-14
D-14
CV
11D
Ifl
PS
D-3S
D-Sl
PES
D-b7
D-71
MEDIAN
1-17
P7S
E.ED
E-E7
PIS
b-D3
b-SS
-------
SUMMER
WINTER
E74
Ell
E.31
1.15
• EDO
• E75
IE-3D
13-DD
E-47
E.D5
D-15
D-14
1D7
IDS
D-3fl
D-4D
D-7E
D-b7
1-37
LED
3-D3
E-3D
fl. bE
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter TP_ug_L_Hedian
15
SEASON
FALL
SPRING
SUMMER
WINTER
N
Iflll
IfltM
E1D4
IbflS
MEAN
1S7
131
14fl
1EE
HIM
• DDD
• DDD
• DDD
• DDD
MAX
E4ED-DD
E3bD-DD
E4DD-DD
E4DD-DD
STDDEV
ESS
E34
EEb
STDERR
5-11
S-4E
4.IE
4.fit
CV
17fl
1SE
PS
S.DD
S.DD
7-SD
S.DD
PES
3S-D
3fl.l
4D-D
3D-D
MEDIAN
7S-D
7D-D
flD-D
bS-D
P7S
IbD
13D
IbD
1ES
PIS
b4S
4bS
S3D
43D
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Turb FTU Median
SEASON
FALL
SPRING
SUMMER
WINTER
N
1D51
1113
1143
111
MEAN
11.D
14-1
14- t
14-S
MIN
• DDD
• bSD
• flDD
• 3DD
MAX
IflD-DD
1E3-DD
IbD-DD
13b-DD
STDDEV
13-4
13-S
IS- t
IS-4
STDERR
D-41
D-4D
D-4b
D-41
CV
1EE
15
IDb
IDb
PS
E-DD
E.SD
E.SD
E.ES
PES
4-SS
4D
as
5.55
MEDIAN
7-7D
11.D
1D-D
1-7D
P7S
lE-fl
lt.fi
17-D
Ifl.D
PIS
EL5
3fl-1
4S-E
43-D
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Turb JCU Median
17
SEASON
FALL
SPRING
SUMMER
WINTER
N
fll
flfl
17
IE
MEAN
ELI
ED-1
ES-fl
lfl.1
MIN
. bDD
• 7DD
• 7E5
LID
MAX
17L
ISfl.
173.
1b.
DD
DD
DD
DD
STDDEV
3L
Efl.
3b •
Ifl.
1
1
t,
fl
STDERR
3-3fl
3-Dfl
3-7E
Lib
CV
145
144
14E
1DD
PS
LID
LSD
LDS
LSD
PES
3-E5
3 • 4b
3-bD
b-7D
MEDIAN
11.D
ID.
11.
13-S
P7S
E4-D
E3-S
3D-D
ELS
PIS
TD-D
flfl.fl
1E7
tD.fi
Aggregate Nutrient Ecoregion: ix
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Turb NTU Median
Ifl
SEASON
FALL
SPRING
SUMMER
WINTER
MEAN
371
47b
3E3
IS.
ED.
ED.
11.b
MIN
• ESD
• 1DD
• DDD
• ESD
MAX
113-DD
175.DD
E1E-DD
1SD-DD
STDDEV
STDERR
ED
as
.fib
• DS
ED-E
D.
L
LIE
CV
1D1
11
1ES
1D3
PS
E.DD
E.ES
E.DD
E.DD
PES
S.SD
fl.7D
t-ED
7-flS
MEDIAN
1.55
15.D
IE-3
14-D
P7S
11.D
ES-D
E4-D
E4-S
PIS
55.D
57-D
7E-S
55.D
-------
APPENDIX B
Descriptive Statistics Data Tables for Level III Subecoregions within Aggregate Ecoregion
-------
Eco_
Level
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Fluo_ug_L_Median
II
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
SEASON
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
N
1
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
11
0
12
0
26
23
33
6
0
0
0
0
9
12
14
MEAN
15. 6
.
10.4
.
.
.
.
.
.
.
.
.
.
.
.
.
4.44
.
11.1
.
11.4
10.9
10. 6
7.99
.
.
.
.
3.18
3.70
13.0
MIN
15. 6
10.4
.400
.900
1.00
1.00
. 625
1.50
.250
.250
1.00
15
10
26
23
36
37
41
13
8
8
95
MAX
. 60
.40
.40
.20
.35
.10
.00
.90
.00
.80
.10
STDDEV STDERR
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
7.48 2.25
.
7.19 2.07
.
10.9 2.14
9.22 1.92
9.61 1.67
3.96 1.62
.
.
.
.
3.10 1.03
2.33 0.67
24.0 6.42
CV
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
169
.
65
.
96
84
91
50
.
.
.
.
98
63
184
15
.
10
.
.
.
.
.
.
.
.
.
.
.
.
.
0.
.
0.
.
1.
1.
1.
1.
.
.
.
.
0.
0.
1.
P5
. 6
.4
40
90
10
13
00
50
25
25
00
P25
15
.
10
.
.
.
.
.
.
.
.
.
.
.
.
.
0.
.
4.
.
3.
2.
3.
7.
.
.
.
.
0.
2.
4.
. 6
.4
90
60
00
70
60
50
63
25
00
MEDIAN
15
10
1.
12
8.
10
9.
8.
2.
4.
6.
. 6
.4
60
.4
20
.5
00
03
20
06
59
P75
15. 6
.
10.4
.
.
.
.
.
.
.
.
.
.
.
.
.
4.20
.
16.9
.
16.5
15.8
11.5
9.00
.
.
.
.
6.30
4.70
8.00
P95
15. 6
.
10.4
.
.
.
.
.
.
.
.
.
.
.
.
.
26.4
.
23.2
.
32.0
24.5
30.9
13.9
.
.
.
.
8.00
8.80
95.1
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Fluo_ug_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
65
71
71
71
71
72
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
12
2
2
9
0
3
2. 61
11.9
4.95
8.52
.
5.77
.200
8.30
.000
2. 60
1.80
8.80
15.40
9.90
20.20
8.80
2.46
5.02
7.00
6.29
.
3.59
0.71
3.55
4.95
2.10
.
2.07
94
42
141
74
.
62
0.20
8.30
0.00
2. 60
.
1.80
0. 63
8.30
0.00
3.85
.
1.80
2.30
11.9
4.95
6.35
6.70
3.75
15.4
9.90
11.5
.
8.80
8.80
15.4
9.90
20.2
.
8.80
-------
72
72
72
74
74
74
74
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
0
2 2.75 1.20
0
2 2.05 2.00
0
0
0
.
4.30 2.19 1.55
.
2.10 0.07 0.05
.
.
.
Eco_
Level_
III
1.20
2.00
1.20 2.75
2.00 2.05
4.30 4.30
2.10 2.10
SEASON
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Phyto_C_F_ug_L_Med
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
-------
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Phyto_C_F_ug_L_Med
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
0
0
1
0
0
1
1
1
1
0
0
0
0
1.
3.
11
9.
0.
90
40
.5
60
78
.
.
1.
.
.
3.
11
9.
90
40
.5
60
.775
.
.
.
.
1
3
11
9
0
.
.
.90
.
.
.40
.45
. 60
.78
.
.
.
.
1.90
1.90
1.90
1.90
1.90
3.40
11.5
9. 60
0.78
3.40
11.5
9. 60
0.78
3.40
11.5
9. 60
0.78
3.40
11.5
9. 60
0.78
3.40
11.5
9. 60
0.78
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Phyto_Spec_A_ug_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
25
29
32
30
22
24
24
21
41
41
44
38
1
0
1
0
11
11
16
6
4
6
11
0
4.84
8. 68
9.99
6.35
6. 62
4.37
6.04
2.85
5.59
4.42
5.47
2.79
6.00
.
3.00
.
10.1
11.3
11.9
3.50
7.90
12.0
20.7
.
.250
.250
.250
.250
.250
.250
.250
.250
.250
.250
.250
.250
6.00
3.00
2.45
3.80
1. 60
1.40
2. 60
1.80
.800
19.
32.
54.
34.
47.
15.
27.
9.
78.
18.
49.
13.
6.
3.
18.
26.
26.
10.
19.
25.
67.
,20
,80
,50
,80
,00
,00
,30
,38
, 60
,90
,53
, 60
,00
,00
,90
,20
,40
,10
,80
,00
,93
5.37
9.76
11.5
8.71
11.1
4.32
7.49
2. 68
12.3
4.38
8.24
3.40
.
.
.
.
5.58
7.74
7.41
3.29
7.99
7. 69
22.4
.
1
1
2
1
2
0
1
0
1
0
1
0
1
2
1
1
4
3
6
.07
.81
.03
.59
.37
.88
.53
.58
.93
. 68
.24
.55
.
.
.
.
. 68
.33
.85
.34
.00
.14
.75
.
Ill
112
115
137
168
99
124
94
221
99
151
122
.
.
.
.
55
68
62
94
101
64
108
.
0
0
0
0
0
0
0
0
0
0
0
0
6
3
2
3
1
1
2
1
0
.25
.25
.25
.25
.25
.25
.25
.25
.25
.25
.25
.25
.00
.
.00
.
.45
.80
. 60
.40
. 60
.80
.80
.
1
1
3
1
0
1
0
0
0
1
0
0
6
3
5
5
6
1
3
9
3
.00
.33
.73
.15
. 68
.01
.44
.79
.25
.16
.88
.25
.00
.
.00
.
.45
.53
.80
.50
.49
.43
.00
.
3.18
5.28
7.36
3.33
1.92
2.53
3.19
1.78
2.28
4.15
2.73
1.92
6.00
3.00
9.95
7.98
11.8
2.55
4. 60
10.4
15.7
5.15
11.3
12.4
7.80
5.98
8.49
10.8
5.28
6.86
5.89
7.10
3.19
6.00
.
3.00
.
15.4
15.9
15.8
2.90
12.3
15.1
22.0
.
16. 6
30. 6
44.3
27.8
23.0
11.0
20.1
7.11
12.8
11.4
17.4
12.8
6.00
.
3.00
.
18.9
26.2
26.4
10.1
19.8
25.0
67.9
.
-------
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
21
21
18
18
49
64
74
2.56
5.80
2.36
1.56
7. 67
7.30
6.75
. 635
1.50
.250
.250
.000
.000
.000
9.43
47.53
7.39
4.13
51.90
98.52
79.20
2.43
10.2
1. 68
0.92
12.1
16. 6
13.3
0.53
2.23
0.40
0.22
1.72
2.08
1.55
95
176
71
59
157
227
198
0. 67
1.87
0.25
0.25
0.00
0.00
0.00
0.94
2.29
1.41
1.00
0.48
0.10
0.00
1.50
2.54
1.79
1.20
3.00
2.20
2.01
3.00
4.00
3.00
1.89
8.05
5.74
7.00
7. 63
19.0
7.39
4.13
38.3
35.9
31.0
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Phyto_Spec_A_ug_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
59
12
9
14
6
1
1
1
0
0
0
0
0
2
3
2
5
1
8
0
5
.45
.74
.53
.35
.13
.00
.50
.74
.
.
.
.
.
.000
.250
.250
. 625
.250
8.00
.500
5.74
14,
10,
5,
21,
2,
8,
0,
5,
.55
.00
.50
.00
.00
.00
.50
.74
3
3
1
5
0
.77
.16
.55
.20
.59
.
.
.
.
.
.
.
.
0.49
0.91
0.52
1.39
0.24
154
84
61
97
52
.
.
.
0
0
0
0
0
8
0
5
.00
.25
.25
. 63
.25
.00
.50
.74
0
1
1
2
1
8
0
5
.00
.50
.50
.00
.00
.00
.50
.74
0,
2,
3,
4,
1,
8,
0,
5,
.59
.50
.00
.25
.00
.00
.50
.74
3
5
3
6
1
8
0
5
.18
.31
.00
.00
.50
.00
.50
.74
12
10
5.
21
2.
8.
0.
5.
.0
.0
50
.0
00
00
50
74
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Phyto_Spec_U_ug_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
-------
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
Eco_
Level_
III
Eco_
Level_
III
29
29
29
29
33
33
33
33
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
SEASON
SEASON
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
0
0
0
0
0
0
0
0
0
0
0
0
0
0.03
0.02
4.37
.025 0.03
.021 0.02
4.37
4.37
0.03
0.02
4.37
0.03
0.02
4.37
0.03 0.03 0.03
0.02 0.02 0.02
4.37
4.37 4.37
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Phyto_Spec_U_ug_L_Median
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Tric_U_ug_L_Median
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
-------
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
0
0
0
0
0
0
0
0
3
2
5
0
4
5
10
0
14
14
14
14
23
22
37
•
.
4.17
3.79
15.9
.
18.2
19.9
31.8
.
1.83
3.24
3.46
1.53
14.4
11.1
9.21
1.25
1.25
8.50
3. 69
2.50
3.09
1.00
1.86
1.28
.960
.000
.000
.000
10.
6.
28.
40.
37.
92.
4.
5.
10.
3.
97.
95.
76.
,00
,33
,00
,90
,50
,78
,19
,20
,99
,02
,78
,06
,55
•
.
5.05
3.59
8.48
.
16. 6
14.2
31.3
.
0.82
0.98
2.57
0.55
23.8
22.5
18.7
2
2
3
8
6
9
0
0
0
0
4
4
3
•
.
.92
.54
.79
.
.32
.36
.89
.
.22
.26
. 69
.15
.96
.80
.08
•
.
121
95
53
.
92
71
98
.
45
30
74
36
166
203
203
1
1
8
3
2
3
1
1
1
0
0
0
0
•
.
.25
.25
.50
.
. 69
.50
.09
.
.00
.86
.28
.96
.00
.00
.00
•
.
1.
1.
8.
.
5.
13
5.
.
1.
2.
2.
1.
0.
0.
0.
25
25
50
91
.7
90
35
65
08
19
00
00
00
1.25
3.79
13.5
14.0
14.7
26.8
1. 60
3.02
2.71
1.31
4.07
3.47
0.00
•
.
10.0
6.33
21.0
.
30.4
31.4
34.1
.
2.03
3.94
3.34
1.93
14.8
7. 65
9.33
•
.
10.0
6.33
28.0
.
40.9
37.5
92.8
.
4.19
5.20
11.0
3.02
58.4
45.4
63.9
Eco_
Level
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chla_Tric_U_ug_L_Median
II
65
71
71
71
71
72
72
72
72
74
74
74
74
SEASON
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
N
34
0
0
2
0
1
0
1
1
3
1
1
1
MEAN
1.87
.
.
8.27
.
27.1
.
25.1
16.9
0.09
8.97
10.2
2.41
MIN
.000
7. 62
27.1
25.1
16.9
.065
8.97
10.2
2.41
MAX
16.
8.
27.
25.
16.
0.
8.
10.
2.
, 68
,92
,10
,10
,90
,12
,97
,20
,41
STDDEV STDERR
3.75 0.64
0.92
0. 65
CV
200
11
P5
0.00
7. 62
27.1
P25
0.00
7. 62
27.1
MEDIAN
0.00
8.27
27.1
0.03
0.01
27
P75
2.53
27.1
P95
12.5
27.1
25.1
16.9
0.07
8.97
10.2
2.41
25.1
16.9
0.07
8.97
10.2
2.41
25.1
16.9
0.10
8.97
10.2
2.41
25.1
16.9
0.12
8.97
10.2
2.41
25.1
16.9
0.12
8.97
10.2
2.41
10
-------
Eco_
Level_
III
SEASON
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chlb_Phyto_C_F_ug_L_Med
11
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Eco_
Level_
III
SEASON
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chlb_Phyto_C_F_ug_L_Med
12
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
65
71
71
71
71
72
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
0.20
0.40
.200
.400
0.20
0.40
0.20 0.20 0.20
0.40 0.40 0.40
0.20 0.20
0.40 0.40
-------
72
72
72
74
74
74
74
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
1
1
1
0
0
0
0
0.43
0.70
0.05
.425
.700
.050
.
.
.
.
0.43
0.70
0.05
.
.
.
.
0.43
0.70
0.05
0.43
0.70
0.05
0.43
0.70
0.05
0.43
0.70
0.05
0.43
0.70
0.05
Eco_
Level_
III
SEASON
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chlb_Phyto_Spec_ug_L_Median
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
13
MEDIAN
P75
P95
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0.24
.236
0.24
0.24
0.24
0.24
0.24
0.24
-------
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Chlb_Phyto_Spec_ug_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
14
P95
65
71
71
71
71
72
72
72
72
74
74
74
74
Eco_
Level_
III
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter DIP_ug_L_Median
15
SEASON
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
11
9
10
9
4
4
4
4
11
12
12
12
3
3
3
3
22
11
23
11
16
16
16
45.3
30.1
27.8
30.1
676
323
365
483
146
48.4
109
60.4
45.0
47.5
84.2
98.3
58.0
60.5
59.1
81.5
44.0
25.2
50.9
.000
5.00
5.00
5.00
60.0
92.5
82.5
52.5
5.00
5.00
5.00
6.25
20.0
12.5
42.5
25.0
18.7
12.5
4.30
23.8
5.00
5.00
5.00
135.00
80.00
92.50
70.00
1412.50
750.00
837.50
1000.00
790.00
295.00
930.00
360.00
70.00
100.00
165.00
202.50
293.02
120.00
176.33
215.00
275.00
102.50
362.50
44.3
24.5
28.1
24.8
683
310
342
479
281
83.0
264
102
25.0
46.3
70.0
92.7
56.3
30.6
48.4
62.0
68.0
28.5
87.8
13.4
8.16
8.89
8.25
342
155
171
239
84.6
24.0
76.2
29.6
14.4
26.7
40.4
53.5
12.0
9.24
10.1
18.7
17.0
7.12
21.9
98
81
101
82
101
96
94
99
192
171
242
170
56
97
83
94
97
51
82
76
155
113
173
0.00
5.00
5.00
5.00
60.0
92.5
82.5
52.5
5.00
5.00
5.00
6.25
20.0
12.5
42.5
25.0
18.9
12.5
7.41
23.8
5.00
5.00
5.00
10.0
10.0
6.25
7.50
95.0
93.8
116
76.3
5.00
10.6
10.0
13.8
20.0
12.5
42.5
25.0
26.1
35.0
18.1
25.0
8.75
5.00
8.13
35.0
25.0
18.8
25.0
615
225
270
440
20.0
13.8
12.5
20.0
45.0
30.0
45.0
67.5
47.6
65.0
47.5
70.0
15.0
12.5
25.0
65.0
35.0
40.0
55.0
1256
553
614
890
65.0
53.8
51.3
47.5
70.0
100
165
203
65.0
82.5
100
125
62.5
32.5
43.8
135
80.0
92.5
70.0
1413
750
838
1000
790
295
930
360
70.0
100
165
203
87.5
120
145
215
275
103
363
-------
45
64
64
64
64
65
65
65
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
16
48
25
62
18
45
45
45
25.7
516
171
68.3
103
33.0
24.8
34. 6
5.00
5.00
5.00
4.25
16.8
5.00
5.00
5.00
125,
9600,
812,
412,
310,
250,
205,
360,
.00
.00
.00
.50
.25
.00
.00
.00
29. 6
1512
221
68.2
82.1
50.9
35.8
60.1
7.39
218
44.2
8. 66
19.4
7.59
5.33
8.96
115
293
129
100
80
154
144
174
5.00
15.0
5.00
7.00
16.8
5.00
5.00
5.00
7.50
70.0
37.0
21.0
40.0
5.00
7.50
7.50
18.1
143
75.0
50.0
86.3
12.5
10.0
12.5
34.8
285
204
96.0
133
25.0
25.0
30.0
125
1551
752
183
310
115
80.0
120
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter DIP_ug_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
16
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
45
13
13
13
12
41
39
39
37
3
3
3
3
22.
94.
48.
80.
65.
86.
52.
70.
66.
38.
33.
38.
30.
,8
,1
,2
, 6
,4
,0
,9
,0
,9
,3
,3
,8
,0
5.00
7.50
7.50
10.0
17.5
.000
.000
.000
.000
5.00
15.0
11.3
5.00
150,
295,
162,
322,
200,
240,
160,
185,
140,
75,
47,
60,
50,
.00
.00
.50
.50
.00
.00
.00
.50
.00
.00
.50
.00
.00
30.
87.
46.
85.
59.
66.
35.
45.
38.
35.
16.
25.
22.
,3
,9
,9
,7
,2
, 6
, 6
, 6
,4
,1
, 6
,0
,9
4.52
24.4
13.0
23.8
17.1
10.4
5. 69
7.30
6.32
20.3
9. 61
14.4
13.2
133
93
97
106
91
78
67
65
57
92
50
64
76
5.00
7.50
7.50
10.0
17.5
5.00
0.00
4.00
1.00
5.00
15.0
11.3
5.00
5.00
35.0
15.0
20.0
30.0
35.2
30.0
35.0
40.0
5.00
15.0
11.3
5.00
12
56
30
60
40
70
50
62
60
35
37
45
35
.5
.3
.0
.0
.0
.0
.0
.5
.0
.0
.5
.0
.0
22.5
135
55.0
80.0
85.0
128
70.0
95.0
93.5
75.0
47.5
60.0
50.0
65.0
295
163
323
200
220
125
170
135
75.0
47.5
60.0
50.0
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter DO_mg_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
17
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
83
82
87
98
26
31
26
30
151
144
146
139
33
27
32
7.
8.
6.
11
7.
7.
6.
9.
6.
7.
5.
9.
6.
8.
5.
88
19
91
.3
24
54
55
76
62
56
58
52
72
15
94
4
4
3
2
2
5
3
8
1
2
1
4
2
6
2
.50
.00
. 60
.90
.90
.00
.40
.10
.20
.80
.20
.55
.50
.15
.20
10.
11.
9.
14.
9.
9.
10.
12.
11.
11.
9.
13.
9.
10.
8.
,70
,45
,45
,70
,45
,90
, 60
,20
,10
,80
, 60
,30
, 60
,53
,45
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
.36
.31
.21
.76
.44
.15
. 69
.02
.75
. 61
. 66
.53
.71
.22
.53
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.15
.14
.13
.18
.28
.21
.33
.19
.14
.13
.14
.13
.30
.24
.27
17
16
17
16
20
15
26
10
27
21
30
16
26
15
26
5
6
4
8
4
5
3
8
3
5
2
6
3
6
2
.55
.10
.85
.10
.88
.20
.80
.25
.40
.40
.40
.90
.43
. 63
. 60
7.
7.
6.
10
6.
6.
5.
9.
5.
6.
4.
8.
6.
7.
5.
00
60
00
.4
20
88
70
00
68
69
55
60
00
35
18
7.
8.
7.
11
7.
7.
6.
9.
6.
7.
5.
9.
6.
7.
6.
95
20
00
.5
45
65
60
60
70
40
75
50
60
90
08
8.
8.
7.
12
8.
8.
7.
10
7.
8.
6.
10
7.
9.
6.
85
80
80
.5
15
35
40
.3
70
48
80
.3
83
25
85
9.
10
8.
14
9.
9.
9.
11
9.
10
7.
12
9.
10
8.
75
.4
40
.1
30
40
75
.7
30
. 6
95
.5
60
.3
40
-------
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
28
104
90
115
75
344
367
371
264
115
91
167
69
352
371
402
10. 6
7.37
9.34
6.74
11.8
8.24
8.93
7.28
10.7
10.2
10.5
8. 63
12.4
7.08
7.73
6.20
6.20
1.25
4.25
.200
6.30
1.70
5. 60
1.50
8.80
6.50
3.30
6.05
9.13
.400
1.80
.450
13,
17,
13,
13,
13,
10,
12,
12,
14,
13,
12,
13,
14,
11,
11,
10,
.80
.88
.80
.10
.80
.95
.00
.00
.10
.85
.90
.20
.10
. 60
.90
. 63
1
2
1
1
1
1
1
1
0
1
1
1
1
1
1
1
.58
.20
.38
.83
.33
.02
.01
.03
.83
.26
.58
.13
.07
.79
. 64
. 66
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.30
.22
.15
.17
.15
.06
.05
.05
.05
.12
.17
.09
.13
.10
.09
.08
15
30
15
27
11
12
11
14
8
12
15
13
9
25
21
27
7.
4.
7.
3.
9.
6.
7.
5.
9.
8.
7.
6.
10
3.
4.
2.
48
10
20
30
21
40
20
40
50
00
30
80
.3
25
70
80
9.80
5.96
8.75
5.88
11.4
7.90
8.30
6.90
10.2
9.40
10.0
7.98
11.9
6.24
6.83
5. 65
10.9
7.41
9.43
6.70
12.0
8.30
8.93
7.43
10. 6
10.3
10.8
8. 60
12.8
7.55
7.90
6.55
11.7
8.58
10.1
7.85
12.7
8.80
9.50
7.85
11.2
10.9
11. 6
9.10
13.1
8.30
8.80
7.25
12.3
10.8
11.5
9.37
13.5
9.70
10.7
8.50
12.1
12.2
12.4
10.9
13.7
9.30
10.1
8.10
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter DO_mg_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
18
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
330
93
79
95
78
84
83
84
80
52
52
54
49
9.57
8.04
9.49
7.36
11.0
7.55
9.43
6.26
11.5
7.71
8.55
6.93
10.2
4.10
.000
4.70
2.50
7. 68
2.33
7.30
.000
7.00
1. 60
5.85
2.35
5.75
13,
12,
12,
10,
14,
11,
12,
8,
13,
11,
12,
13,
12,
.20
.50
.40
.10
. 60
.80
.40
.85
.80
.90
.15
.50
.40
1
2
1
1
1
2
1
1
0
1
1
1
1
.51
.09
.22
.46
.28
.04
.04
.52
.99
.78
.31
.74
.38
0
0
0
0
0
0
0
0
0
0
0
0
0
.08
.22
.14
.15
.15
.22
.11
.17
.11
.25
.18
.24
.20
16
26
13
20
12
27
11
24
9
23
15
25
14
6.
4.
7.
4.
8.
4.
8.
3.
10
3.
6.
3.
7.
90
00
70
70
80
00
05
60
.3
90
60
35
20
8. 60
7.45
8.75
6.40
10.2
6.30
8.80
5.38
11.1
6.80
7.55
6.15
9.50
9.80
8.20
9.50
7. 60
10.9
7. 63
9.20
6.40
11. 6
8.25
8.55
7.20
10.4
10. 6
9.20
10.1
8.50
11.8
8.95
10.1
7.30
12.1
8.70
9.39
7.70
11.1
11.8
11.0
11. 6
9.45
13.0
11.0
11.3
8.40
13.0
9.88
10.5
9.30
12.3
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter N02_N03_mg_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
19
29
29
29
29
33
33
33
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
74
65
67
78
24
22
21
0.57
0.37
0.33
0.46
2.31
1.33
1. 60
.010
.010
.000
.025
.010
.093
.010
5.40
3.75
6.20
4.00
8.32
5.43
6.84
1.08
0. 60
0.79
0. 66
2.99
1. 67
2.30
0.13
0.07
0.10
0.07
0. 61
0.36
0.50
189
164
235
143
130
125
144
0.01
0.03
0.01
0.05
0.02
0.11
0.02
0.05
0.09
0.07
0.12
0.09
0.21
0.11
0.13
0.15
0.13
0.21
0.91
0. 68
0.35
0.48
0.39
0.35
0.49
4.38
1. 67
2.04
3.36
1.41
0.92
1.70
8.27
5.35
6. 60
-------
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
25
142
134
140
143
35
30
37
32
125
111
137
78
315
332
327
241
62
61
77
53
439
496
518
2.13
0.56
0.37
0.43
0.33
0.57
0.41
0.48
0.52
0.82
1.03
1.03
1.25
0.73
0. 64
0.73
0.70
2.24
2.20
2.05
2.74
0.45
0.39
0.41
.070
.005
.005
.005
.005
.003
.025
.005
.093
.000
.005
.000
.025
.003
.000
.003
.020
.330
.110
.120
. 660
.000
.000
.000
8.45
9.08
4.45
6.15
6.34
7.16
4.92
6.84
6.12
7.84
9.80
9.03
9.38
8.85
9.30
7.00
8.78
9.02
7.70
6.27
9.76
5.95
5.46
4.70
2.51
1.43
0.72
0.92
0.72
1.38
0.89
1.27
1.05
1.42
1.59
1.72
1.71
1.26
1.03
1.14
1.03
1.77
1.76
1.47
1.97
0.76
0.57
0. 62
0.50
0.12
0.06
0.08
0.06
0.23
0.16
0.21
0.19
0.13
0.15
0.15
0.19
0.07
0.06
0.06
0.07
0.22
0.23
0.17
0.27
0.04
0.03
0.03
118
254
195
212
220
243
215
265
205
172
153
167
137
173
162
157
148
79
80
72
72
168
147
152
0.10
0.01
0.03
0.01
0.02
0.01
0.05
0.01
0.10
0.00
0.05
0.00
0.13
0.03
0.04
0.01
0.06
0.52
0.55
0.23
0.80
0.01
0.01
0.01
0.16
0.04
0.09
0.06
0.07
0.03
0.10
0.05
0.15
0.11
0.26
0.20
0.40
0.12
0.19
0.17
0.21
0.98
0.96
1.01
1.57
0.07
0.10
0.09
0.77
0.11
0.15
0.14
0.14
0.07
0.17
0.13
0.27
0.34
0.51
0.50
0. 67
0.33
0.37
0.37
0.38
1.73
1. 63
1. 69
2.16
0.20
0.20
0.21
3.42
0.26
0.32
0.29
0.25
0.34
0.32
0.23
0.45
0.76
1.01
0.83
1.24
0.71
0. 64
0.75
0.73
3.00
2.70
2.80
3.10
0.44
0.43
0.45
6.51
3.70
1.51
2. 65
1.19
4.25
1.25
4.05
1.28
4.20
4.92
5. 63
6.32
3.26
2.23
3.11
2.40
5.80
6.24
5.57
8.28
1.88
1.50
1. 66
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter N02_N03_mg_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
20
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
433
107
94
109
91
151
124
173
151
53
60
65
53
0
0
1
0
1
0
1
1
1
0
0
0
0
.44
.99
.05
.98
.36
.97
.53
.13
.58
.28
.52
.48
.43
.000
.003
.025
.012
.003
.000
.023
.003
.003
.005
.020
.024
.033
4.
10.
5.
4.
5.
5.
8.
8.
9.
1.
3.
6.
1.
,10
,00
,41
,72
,34
,70
,45
,80
,00
,05
,30
,00
,73
0
1
1
1
1
1
1
1
1
0
0
1
0
. 60
.50
.06
.01
.19
.24
.81
. 61
.84
.23
. 67
.00
.41
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
03
14
11
10
13
10
16
12
15
03
09
12
06
138
151
101
103
88
127
118
142
116
81
129
210
95
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
01
03
13
06
11
01
07
02
05
04
03
03
08
0
0
0
0
0
0
0
0
0
0
0
0
0
.10
.20
.40
.29
.49
.14
.29
.14
.39
.14
.14
.09
.15
0,
0,
0,
0,
1,
0,
0,
0,
0,
0,
0,
0,
0,
.23
.44
. 60
. 62
.04
.44
.86
.46
.83
.21
.27
.18
.27
0
1
1
1
1
1
1
1
2
0
0
0
0
.51
.35
.17
.20
.72
.40
.90
.45
.13
.33
. 63
.49
.55
1
2
3
2
4
3
5
4
5
0
2
1
1
.57
.72
.38
.95
.20
.75
.50
.45
.98
. 69
.11
.20
.55
-------
Eco_
Level
Eco_
Level_
III
65
71
71
71
71
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Org_P_ug_L_Median
21
II
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
SEASON
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
N
1
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
11
0
12
0
0
0
0
0
0
0
0
0
0
0
0
MEAN MIN
37.6 37.6
.
36.5 36.5
.
.
.
.
.
.
.
.
.
.
.
.
.
73.3 22.5
.
53.7 23.1
.
.
.
.
.
.
.
.
.
.
.
.
MAX STDDEV STDERR CV P5
37.64 . . . 37.6
.
36.48 . . .36.5
.
.
.
.
.
.
.
.
.
.
.
.
.
188.30 52.1 15.7 71 22.5
.
115.44 25.3 7.30 47 23.1
.
.
.
.
.
.
.
.
.
.
.
.
P25 MEDIAN
37.6 37.6
36.5 36.5
P75 P95
37.6 37.6
36.5 36.5
37. 6 58.6
36.4 49.8
84.1 188
64.3 115
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Org_P_ug_L_Median
22
SEASON
WINTER
FALL
SPRING
SUMMER
WINTER
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
-------
72
72
72
72
74
74
74
74
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
3
0
2
0
0
0
0
0
70.6 34.6 138.53 58.9
.
52.0 6.77 97.22 64.0
.
.
.
.
.
34.0 83 34.6 34.6 38.7
.
45.2 123 6.77 6.77 52.0
.
.
.
.
.
139 139
97.2 97.2
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Orthophosphate_T_as_P_ug_L_Med
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
23
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
5
5
5
4
3
3
3
3
10
13
13
13
3
3
3
3
11
11
11
11
8
8
7
8
6
6
6
6
34
34
34
45.0
46.5
54.3
90.9
920
733
822
522
265
92.8
153
50.4
90.0
64.2
95.8
102
87.7
85.9
88.5
104
63.8
36.3
74.3
38.0
257
160
128
96.3
32. 6
27.8
36.0
20.0
22.5
25.0
31.3
60.0
70.0
103
70.0
5.00
12.5
10.0
12.5
30.0
27.5
47.5
30.0
30.0
12.5
20.0
30.0
5.00
5.00
7.50
5.00
20.0
25.0
5.00
20.0
5.00
5.00
5.00
60.00
70.00
97.50
225.00
1600.00
1095.00
1307.50
815.00
1600.00
550.00
897.50
130.00
200.00
125.00
185.00
225.00
130.00
210.00
150.00
240.00
255.00
112.50
240.00
115.00
595.00
452.50
285.00
180.00
150.00
120.00
310.00
15.8
22.3
26.9
91.0
786
575
635
397
525
149
295
36.4
95.4
53.1
77.3
107
33.6
58.6
39.8
68.9
82.8
36.4
82.8
38.4
219
165
113
65.8
41.1
28.9
57.4
7.07
9.99
12.0
45.5
454
332
367
229
166
41.4
81.9
10.1
55.1
30.6
44.6
61.9
10.1
17.7
12.0
20.8
29.3
12.9
31.3
13.6
89.3
67.2
46.0
26.9
7.05
4.95
9.85
35
48
50
100
85
78
77
76
198
161
193
72
106
83
81
106
38
68
45
66
130
100
111
101
85
103
88
68
126
104
160
20.0
22.5
25.0
31.3
60.0
70.0
103
70.0
5.00
12.5
10.0
12.5
30.0
27.5
47.5
30.0
30.0
12.5
20.0
30.0
5.00
5.00
7.50
5.00
20.0
25.0
5.00
20.0
5.00
5.00
5.00
40.0
30.0
43.8
34.4
60.0
70.0
103
70.0
12.5
26.3
20.0
30.0
30.0
27.5
47.5
30.0
50.0
37.5
55.0
40.0
10.0
12.5
15.0
9.38
40.0
25.0
21.5
27.5
5.00
7.50
10.0
50.0
40.0
47.5
53.8
1100
1033
1055
680
40.0
35.0
32.5
37.5
40.0
40.0
55.0
50.0
95.0
65.0
90.0
95.0
40.0
23.1
31.3
22.5
250
110
118
95.0
20.0
18.1
16.9
55.0
70.0
57.5
148
1600
1095
1308
815
95.0
60.0
70.0
70.0
200
125
185
225
118
130
120
170
75.0
50.6
110
60.0
385
238
220
160
30.0
40.0
29.5
60.0
70.0
97.5
225
1600
1095
1308
815
1600
550
898
130
200
125
185
225
130
210
150
240
255
113
240
115
595
453
285
180
150
105
120
-------
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Orthophosphate_T_as_P_ug_L_Med
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
24
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
34
10
10
10
9
7
7
8
7
3
3
3
3
29.5
90.0
74.9
114
111
92.9
72.5
117
103
48.3
105
53.3
66.7
5.00
5.00
5.00
5.00
21.3
15.0
10.0
20.0
20.0
5.00
80.0
10.0
17.5
155,
270,
282,
575,
260,
175,
182,
255,
157,
75,
125,
100,
102,
.00
.00
.50
.00
.00
.00
.50
.00
.50
.00
.00
.00
.50
31.
84.
86.
,4
,1
,8
169
83.
58.
54.
69.
50.
37.
22.
45.
44.
,4
,7
,7
,4
,1
,9
,9
,1
,0
5.
26
27
53
27
22
20
24
18
21
13
26
25
39
. 6
.4
. 6
.8
.2
.7
.5
.9
.9
.2
.0
.4
107
93
116
149
75
63
75
60
49
78
22
85
66
5.00
5.00
5.00
5.00
21.3
15.0
10.0
20.0
20.0
5.00
80.0
10.0
17.5
7.50
20.0
20.0
17.5
50.0
30.0
37.5
77.5
50.0
5.00
80.0
10.0
17.5
15. 6
80.0
36.3
77.5
90.0
120
60.0
110
120
65.0
110
50.0
80.0
35.0
120
133
95.0
130
130
87.5
141
140
75.0
125
100
103
90.0
270
283
575
260
175
183
255
158
75.0
125
100
103
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter TKN_mg_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
25
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
83
83
83
93
29
33
30
32
125
110
124
137
20
19
24
26
79
76
81
49
301
328
338
279
0. 60
0. 65
0. 64
0.58
0.91
0.83
0.83
0.77
0. 67
0.71
0.78
0. 68
0.80
0.98
0.82
0.82
1.17
1.08
1.11
0.87
0.47
0.45
0.49
0.40
.050
.125
.050
.050
.240
.390
.330
.200
.010
.050
.050
.050
.200
.345
.240
.220
.175
.315
.193
.125
.025
.025
.025
.025
1.75
1.84
2.75
2.28
5.40
1. 63
1.88
3.08
2. 61
2. 63
3.80
4. 65
1.80
2.83
1. 66
3. 60
5.00
4.02
3.10
4.33
3.20
3.95
3.00
1.84
0.33
0.34
0.41
0.33
0.91
0.25
0.37
0.50
0.40
0.45
0.54
0. 60
0.47
0. 68
0.35
0.84
0.95
0. 68
0.56
0.73
0.42
0.48
0.40
0.28
0.04
0.04
0.05
0.03
0.17
0.04
0.07
0.09
0.04
0.04
0.05
0.05
0.10
0.15
0.07
0.16
0.11
0.08
0.06
0.10
0.02
0.03
0.02
0.02
54
52
64
58
100
30
45
65
59
63
69
89
58
69
42
102
81
63
51
84
90
108
81
69
0.17
0.25
0.21
0.19
0.35
0.46
0.36
0.29
0.23
0.05
0.20
0.20
0.22
0.35
0.49
0.22
0.45
0.33
0.50
0.30
0.10
0.10
0.09
0.10
0.40
0.40
0.40
0.38
0.57
0.70
0.50
0.52
0.43
0.45
0.51
0.40
0.50
0. 60
0.56
0.43
0. 60
0. 65
0.70
0.50
0.24
0.23
0.29
0.23
0.55
0. 60
0.56
0.56
0.71
0.80
0.81
0. 62
0. 60
0. 63
0.70
0.55
0. 67
0.70
0.72
0.55
0.90
0.96
1.00
0. 60
0.31
0.33
0.40
0.35
0.79
0.73
0.78
0. 65
0.97
0.93
0.99
1.00
0.80
0.84
0.88
0.74
1.19
1.20
1.08
0.78
1.27
1.28
1.35
0.89
0.56
0.50
0.59
0.50
1.20
1.35
1.45
1.16
1. 60
1.33
1.58
1.30
1.45
1.59
1.80
1.38
1. 68
2.83
1.50
3.37
4.55
1.98
2.25
2.30
1.23
1.10
1.22
1.04
-------
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
98
98
125
78
453
515
554
0.59
0. 60
0.59
0.55
0.50
0.49
0.58
.050
.050
.050
.100
.000
.000
.000
3.01
2. 68
3.88
1.90
4.10
3.93
4.30
0.51
0.52
0.57
0.38
0.38
0.34
0.41
0.05
0.05
0.05
0.04
0.02
0.02
0.02
87
87
96
69
75
70
71
0.10
0.05
0.05
0.15
0.10
0.13
0.17
0.30
0.31
0.30
0.30
0.30
0.30
0.34
0.43
0.46
0.50
0.42
0.42
0.42
0.49
0.80
0. 65
0. 65
0.70
0. 60
0. 60
0.74
85
60
20
50
10
00
28
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter TKN_mg_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
26
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
492
72
56
65
48
120
104
154
134
24
30
31
29
0.45
0.71
0.45
0.56
0.47
0.93
0.97
0.85
0. 68
0.72
1.07
0.88
0. 67
.000
.050
.035
.110
.050
.025
.025
.025
.025
.195
.110
.093
.163
4.18
3. 60
1.58
2.47
1. 62
4.80
4.80
3.84
2.40
1. 65
5.00
4.10
1. 60
0.34
0. 68
0.31
0.41
0.30
0.75
0.75
0.45
0.41
0.41
1.30
0.76
0.40
0.02
0.08
0.04
0.05
0.04
0.07
0.07
0.04
0.04
0.08
0.24
0.14
0.07
76
97
68
73
63
81
77
53
60
57
122
87
59
0.12
0.10
0.05
0.15
0.09
0.28
0.30
0.30
0.03
0.25
0.16
0.26
0.17
0.28
0.29
0.27
0.30
0.28
0.53
0. 60
0.55
0.39
0.38
0.35
0.40
0.32
0.40
0.46
0.40
0.46
0.44
0.79
0.80
0.84
0. 65
0.70
0.58
0. 67
0.55
0.55
0.90
0.54
0.75
0. 61
0.99
1.07
1.04
0.90
0.96
1.25
1.05
0.88
0.94
1.82
1.00
1.20
0.90
2.70
2.30
1.44
1.40
1.40
4.85
2.30
1.34
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter TN_mg_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
27
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
13
14
20
21
3
3
3
3
10
12
19
18
3
3
8
8
1
1
0
1
4
2
3
3
1
0
1
0
1
1
0
1
.29
.26
.80
.24
.73
. 60
.53
.94
.34
.75
.49
. 69
.10
.06
.94
.02
.450
.330
.250
.520
. 600
1.10
1.04
.830
.300
.400
.270
.360
. 600
.760
.500
.450
2.
4.
1.
3.
7.
4.
5.
6.
4.
1.
11.
2.
1.
1.
1.
2.
,80
,30
,45
, 66
,70
,30
,30
,08
,90
, 60
,00
,58
,90
, 60
,40
,15
0
1
0
0
3
1
2
2
1
0
2
0
0
0
0
0
.81
.04
.36
.70
. 69
. 61
.22
.75
.71
.38
.59
.52
.70
.47
.27
.57
0
0
0
0
2
0
1
1
0
0
0
0
0
0
0
0
.22
.28
.08
.15
.13
.93
.28
.59
.54
.11
.59
.12
.40
.27
.09
.20
63
83
45
56
78
62
63
70
128
51
174
76
64
44
29
56
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
0
.45
.33
.30
.59
. 60
.10
.04
.83
.30
.40
.27
.36
. 60
.76
.50
.45
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
0
.80
.56
.51
.88
. 60
.10
.04
.83
.35
.51
.37
.41
. 60
.76
.85
. 61
1,
1,
0,
0,
5,
2,
4,
4,
0,
0,
0,
0,
0,
0,
0,
0,
.00
.13
.77
.95
.90
.40
.25
.90
. 68
.55
. 62
.52
.80
.82
.87
.84
1
1
1
1
7
4
5
6
0
1
0
0
1
1
1
1
.17
.45
.04
.50
.70
.30
.30
.08
.81
.03
.87
. 67
.90
. 60
.08
.33
2.
4.
1.
2.
7.
4.
5.
6.
4.
1.
11
2.
1.
1.
1.
2.
80
30
42
00
70
30
30
08
90
60
.0
58
90
60
40
15
-------
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
30
19
31
19
18
17
18
16
37
38
76
30
64
65
65
1
1
1
1
1
0
0
1
4
4
4
4
1
1
1
.29
.93
.38
.54
.00
.95
.93
.03
.08
.07
.84
.48
.00
.06
.03
.180
.340
.220
.490
.200
.300
.200
.275
.567
.547
.552
1.85
.290
.360
.385
5,
7,
7,
5,
2,
1.
2,
2,
12,
11.
12,
13,
3,
2,
2,
.10
.90
.25
.20
.98
.80
.45
. 69
.50
.00
.30
.00
.10
.94
.75
1
1
1
1
0
0
0
0
3
2
2
3
0
0
0
.04
.83
.34
.23
. 68
.38
. 60
. 61
.30
.50
.92
.04
.59
.56
.54
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.19
.42
.24
.28
.16
.09
.14
.15
.54
.41
.34
.55
.07
.07
.07
81
95
97
80
69
41
64
60
81
61
60
68
59
53
52
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
.25
.34
.33
.49
.20
.30
.20
.28
. 63
. 65
.44
.88
.40
.51
.46
0
0
0
0
0
0
0
0
1
2
2
2
0
0
0
.72
. 67
.70
.75
.56
.70
.48
. 67
. 65
.10
.49
.35
.57
. 66
. 65
0,
1,
0,
1,
0,
0,
0,
0,
3,
3,
4,
3,
0,
0,
0,
.98
.48
.94
.06
.70
.89
.86
.84
.12
. 63
.16
. 60
.75
.90
.83
1
2
1
1
1
1
1
1
4
5
7
4
1
1
1
.45
.43
.70
.95
.30
.23
.41
.29
.02
.25
.08
.57
.34
.30
.36
3.83
7.90
3. 66
5.20
2.98
1.80
2.45
2. 69
11.0
10.0
10.7
12.0
2.20
2.08
2.06
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter TN_mg_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
28
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
65
10
10
10
9
22
20
21
19
3
3
3
3
1
1
1
1
2
2
3
2
4
0
1
0
0
.10
.35
. 61
.73
.28
.86
.86
.74
.10
.96
.22
.81
.99
.300
.370
.550
.740
.700
.230
.943
.280
. 660
.570
.935
. 630
.555
2.
3.
4.
4.
5.
6.
7.
6.
8.
1.
1.
0.
1.
,94
, 60
, 65
,05
,40
,30
,88
,18
,20
,20
,45
,95
,30
0
1
1
1
1
1
2
1
2
0
0
0
0
. 67
.14
.43
.12
.53
.73
.29
.58
.32
.34
.26
.16
.39
0
0
0
0
0
0
0
0
0
0
0
0
0
.08
.36
.45
.36
.51
.37
.51
.34
.53
.20
.15
.09
.22
61
84
89
65
67
61
59
58
57
35
21
20
39
0
0
0
0
0
0
1
0
0
0
0
0
0
.40
.37
.55
.74
.70
.46
.09
. 61
. 66
.57
.94
. 63
.56
0
0
0
0
1
1
1
1
2
0
0
0
0
.59
.51
.72
.88
.35
.32
.81
.52
.40
.57
.94
. 63
.56
0,
0,
0,
1,
2,
2,
3,
2,
4,
1,
1,
0,
1,
.85
.97
.94
.35
.00
.86
.72
.35
.06
.10
.28
.84
.10
1
1
1
2
2
4
5
3
6
1
1
0
1
. 63
. 65
.70
.00
.30
.26
. 62
.73
.16
.20
.45
.95
.30
2
3
4
4
5
5
7
4
8
1
1
0
1
.30
. 60
. 65
.05
.40
.03
.76
.98
.20
.20
.45
.95
.30
Eco_
Level_
III
SEASON
MEAN
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter TP_ug_L_Median
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
29
29
29
29
29
33
33
33
33
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
85
84
90
100
29
35
28
31
163
131
106
141
486
420
381
352
2.50
2.50
2.50
2.50
40.0
50.0
50.0
20.0
1500,
1235,
690,
1430,
2120,
2360,
1640,
1210,
.00
.00
.00
.00
.00
.00
.00
.00
265
188
125
201
572
493
420
351
28.
20.
13.
20.
,7
,5
,2
,1
106
83.
79.
63.
,3
,4
,1
163
143
118
142
118
117
110
100
20.0
16.3
10.0
8.13
50.0
50.0
50.0
40.0
40.0
35.0
30.0
43.8
90.0
140
110
90.0
75.0
70.0
50.0
87.5
265
218
213
200
155
135
140
170
495
480
450
660
445
475
385
380
1800
1630
1230
1100
-------
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
158
153
164
160
34
31
39
33
139
126
146
96
395
425
436
322
110
108
181
86
532
603
650
173
151
159
143
176
188
229
167
242
261
242
195
130
104
145
93.0
182
144
150
114
82.0
72.8
95.8
2.50
2.50
2.50
2.50
5.00
5.00
17.5
5.00
10.0
10.0
20.0
2.50
.000
.000
.000
.000
2.50
.000
2.50
.000
.000
.000
.000
2420
2090
1510
1710
1345
1440
1592
1380
1880
2140
2040
2140
1650
1187
2400
1200
1335
1755
1760
550
1770
990
1700
.00
.00
.00
.00
.00
.00
.50
.00
.00
.00
.00
.00
.00
.50
.00
.00
.00
.00
.00
.00
.00
.00
.00
316
258
247
251
278
345
389
316
299
377
284
320
221
159
266
137
243
233
237
124
139
96.6
132
25.1
20.9
19.3
19.8
47.8
62.1
62.3
55.0
25.3
33.6
23.5
32.7
11.1
7.72
12.7
7.64
23.1
22.4
17.6
13.4
6.01
3.94
5.18
183
171
155
175
158
184
170
189
124
144
117
164
170
153
184
147
134
162
157
108
169
133
138
10.0
10.0
10.0
18.8
11.3
5.00
20.0
5.00
41.2
40.0
49.3
10.0
10.0
10.0
9.00
6.25
10.0
20.0
10.0
10.0
0.00
0.00
0.00
50
50
50
45
45
37
50
40
95
90
.0
.0
.0
.0
.0
.5
.0
.0
.0
.0
100
43
30
35
30
30
40
42
40
40
20
25
30
.8
.0
.0
.0
.0
.0
.5
.0
.0
.0
.0
.0
75.0
72.5
80.0
70.0
70.0
70.0
90.0
60.0
150
135
156
87.5
56.3
50.0
60.0
51.3
85.0
70.0
70.0
70.0
50.0
50.0
60.0
140
150
147
130
150
120
170
100
240
255
260
198
115
95.0
124
100
220
130
150
130
95.0
90.0
120
778
510
700
450
925
1215
1515
1045
930
1040
940
975
565
415
625
310
793
590
510
450
255
185
270
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter TP_ug_L_Median
30
Eco_
Level_
III
SEASON
MEAN
MIN
MAX
STDDEV
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
543
115
98
117
94
156
136
183
160
58
65
70
60
79.7
145
80.9
142
124
275
231
203
174
243
219
212
195
.000
2.50
2.50
2.50
2.50
2.50
10.0
.000
.000
2.50
10.0
.000
2.50
2400.
1900.
625.
1150.
1410.
1800.
2300.
1400.
920.
1125.
2170.
1200.
840.
00
00
00
00
00
00
00
00
00
00
00
00
00
163
250
112
203
216
306
373
199
164
279
338
228
170
STDERR
6.98
23.3
11.3
18.8
22.2
24.5
32.0
14.7
12.9
36.7
42.0
27.3
22.0
CV
P5
P25
MEDIAN
P75
P95
204
173
138
143
174
111
162
98
94
115
154
107
87
0.00
4.50
2.50
2.50
5.00
20.0
30.0
25.0
20.0
25.0
25.0
20.0
13.1
20.
30.
20.
30.
30.
0
0
0
0
0
110
86.
80.
70.
50.
70.
80.
81.
3
0
0
0
0
0
3
45.0
75.0
40.0
60.0
60.0
190
138
163
140
110
123
140
134
80.0
140
90.0
163
97.5
279
241
240
214
370
205
250
291
215
435
325
615
475
948
740
530
500
970
760
660
530
-------
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Turb FTU Median
31
Eco_
Level_
III
SEASON
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
53
46
46
52
6
8
7
7
47
57
42
57
6
17
7
17
71
73
78
70
342
357
356
271
46
28
30
29
358
418
426
23.0
22.9
26.1
30.1
27.8
42.2
44.4
43.9
14.5
18.3
14.8
18.7
24.7
24.8
28.8
22.2
19.2
30.3
31.5
13. 6
9.87
13.1
13.1
15.9
2.78
5.22
7.01
5.81
6.86
9. 61
11.5
2.10
.900
.900
.800
1.10
1.00
8.50
7.50
2.20
1.80
1.30
2.55
3. 60
5.50
12.0
4.80
3.90
3.00
1.40
1.00
1.00
1.00
1.25
1.40
.450
1.00
.800
.400
.000
. 650
1.10
95.
96.
81.
117.
87.
64.
110.
93.
55.
75.
77.
63.
57.
57.
50.
48.
67.
123.
74.
72.
110.
106.
102.
136.
8.
11.
16.
15.
41.
54.
156.
,00
,00
,00
,00
,00
,00
,00
,50
,00
,00
,00
,75
,50
,00
,00
,00
,00
,00
,50
,75
,00
,00
,50
,00
,75
,10
,75
,08
,03
,00
,00
25.1
22.2
22.7
26.9
31.8
23. 6
39.1
36.0
11.8
12.9
15.2
13.2
19.8
15. 6
15.1
15.9
12.4
25.9
17.2
13. 6
8.05
8.98
9. 64
12.0
1.90
2. 69
4.16
3. 65
5.46
7.57
14.9
3.
3.
3.
3.
13
8.
14
13
1.
1.
2.
1.
8.
3.
5.
3.
1.
3.
1.
1.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
45
27
34
73
.0
36
.8
. 6
72
71
34
75
08
79
70
86
48
03
94
63
44
48
51
73
28
51
76
68
29
37
72
109
97
87
89
114
56
88
82
81
71
103
71
80
63
52
72
65
86
55
100
81
68
74
76
68
52
59
63
80
79
130
2.
3.
4.
3.
1.
1.
8.
7.
2.
3.
2.
2.
3.
5.
12
4.
7.
7.
8.
2.
2.
2.
2.
3.
0.
1.
1.
1.
1.
2.
2.
90
10
68
50
10
00
50
50
60
50
95
70
60
50
.0
80
00
30
00
00
95
95
65
63
70
13
00
00
80
00
20
5.95
7.10
10. 6
11.5
7.10
21.9
11.8
10.0
6.00
9.00
6.00
7.88
8.00
15.0
17.5
12.0
11.0
13.5
19.0
5.10
5.93
7. 65
7.33
8. 68
1.20
3.30
4.05
3.00
3.40
4. 60
4.85
11.8
13.0
15.5
20.4
19.3
55.0
29.7
24.0
10.1
15.3
8. 69
19.0
23.0
20.0
22.5
15.0
16.8
20.7
27.3
8.30
8.50
12.0
11.8
14.0
2.25
5.10
6.08
5.25
5.30
7.50
7.88
29.0
32.5
42.5
44.5
33.0
59.3
81.8
79.0
19.9
25.0
21.5
25.0
33.0
32.0
49.4
32.0
22.5
38.7
41.5
17.3
12.0
16.0
16.0
20.0
3.80
7.05
9.40
7.30
8.50
11.9
12.0
89
66
73
99
87
64
.5
.0
.8
.0
.0
.0
110
93
40
47
47
45
57
57
50
48
40
92
67
38
19
25
27
32
6.
10
16
15
17
24
28
.5
.0
.0
.0
.5
.5
.0
.0
.0
.8
.0
.0
.0
.5
.5
.0
.5
40
.1
.5
.0
.0
.0
.8
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Turb FTU Median
32
Eco_
Level_
III
SEASON
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
65
71
71
71
71
72
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
350
20
21
22
13
96
10.4
9.18
13.4
15.3
19.7
17.2
.300
1.45
1.80
1.95
1.80
1.00
123.50
18.40
41.00
47.15
70.00
180.00
12. 6
5.17
10.5
10.8
18.1
24.3
0. 67
1.16
2.30
2.31
5.03
2.48
122
56
78
71
92
141
1.85
1.55
2.40
2.25
1.80
2.70
4.08
5.09
6.40
8.20
8.50
7.36
6.75
8.45
10.1
13.7
14.9
12.0
11.0
13.3
17.0
19.4
25.2
20.3
31.4
18.2
31.0
34.5
70.0
32.0
-------
72
72
72
74
74
74
74
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
77
118
112
14
11
11
13
15.
13.
10.
19.
29.
24.
44.
,8
,5
,8
,9
,9
, 6
,3
2.80
1.00
1.30
1.00
4.00
2.50
14.8
61.
160,
93,
120,
64,
62,
92,
.50
.00
.50
.00
.00
.50
.75
11.
16.
10.
31.
18.
23.
26.
,5
, 6
,8
,5
,2
,0
,5
1
1
1
8
5
6
7
.31
.53
.02
.42
.49
.92
.35
73
123
100
158
61
93
60
4. 60
2.70
2. 60
1.00
4.00
2.50
14.8
9.00
5.10
5.16
3.00
22.3
7.00
20.0
13.0
9.45
7. 68
6.50
28.3
9.50
42.5
17.8
16.9
12.8
26.5
34.0
49.0
62.5
48.0
35.0
30.0
120
64.0
62.5
92.8
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Turb JCU Median
33
Eco_
Level_
III
SEASON
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
11
11
17
15
0
0
0
0
5
0
8
7
5
3
7
5
14
13
19
11
11
11
10
12
1
1
2
2
17
21
11
50.2
39.0
47.1
32.3
.
.
.
.
56.2
.
46.4
31.8
20.2
62.3
31.9
16.0
35.5
37. 6
26.3
20.4
8.04
12.8
11.8
11. 6
3.73
6.50
4.30
5.53
16.5
10.5
20. 6
2
2
2
2
3
2
4
2
.00
.00
.35
.00
.50
.00
.00
.00
19.0
1
2
4
4
7
1
2
1
3
3
6
4
4
2
1
1
.00
.00
.90
700
.90
.00
.70
.10
.10
. 60
.73
.50
.10
.70
.30
.75
. 60
171.
158.
173.
79.
140.
127.
72.
62.
115.
61.
26.
134.
130.
100.
57.
30.
29.
23.
19.
3.
6.
4.
6.
80.
29.
135.
,00
,00
,00
,10
,50
,00
,00
,00
,00
,00
,00
,50
,50
,00
,00
,00
,00
,10
,50
,73
,50
,50
,35
,00
,30
,00
51.0
45.8
59.1
23.4
.
.
.
.
57.4
.
48.7
24.0
23.9
48.7
20.3
9.35
32.8
37.9
22.9
13.4
8.03
7.01
8.52
4.87
.
.
0.28
1.17
18.8
6. 63
38.4
15.4
13.8
14.3
6.04
.
.
.
.
25.7
.
17.2
9.06
10.7
28.1
7. 66
4.18
8.77
10.5
5.25
4.04
2.42
2.11
2. 69
1.40
.
.
0.20
0.83
4.55
1.45
11. 6
102
117
125
72
.
.
.
.
102
.
105
75
118
78
64
58
93
101
87
66
100
55
72
42
.
.
7
21
114
63
186
2.
2.
2.
2.
.
.
.
.
3.
.
2.
4.
2.
19
1.
2.
4.
0.
4.
7.
1.
2.
1.
3.
3.
6.
4.
4.
2.
2.
1.
00
00
35
00
50
00
00
00
.0
00
00
90
70
90
00
70
10
10
60
73
50
10
70
30
15
60
3.80
11.0
7.25
13.0
.
.
.
.
22.0
.
5.00
13.0
10.0
19.0
16.5
14.0
16.5
10.0
10.0
11.0
3.05
9. 60
2.10
8.85
3.73
6.50
4.10
4.70
7.50
5. 60
2.88
35.0
25.0
21.0
31.3
25.0
25.9
21.5
12.8
53.0
27.0
15.0
26.5
31.0
20.0
17.5
5.70
12.1
12.3
10.5
3.73
6.50
4.30
5.53
11.1
11.0
9.30
79.5
46.0
46.5
44.0
.
.
.
.
90.0
.
90.0
48.0
14.0
115
47.0
23.0
35.5
42.0
36.5
23.0
11.0
17.0
20.5
15.4
3.73
6.50
4.50
6.35
18.0
13.0
15.0
171
158
173
79.1
.
.
.
.
141
.
127
72.0
62.0
115
61.0
26.0
135
131
100
57.0
30.0
29.0
23.1
19.5
3.73
6.50
4.50
6.35
80.0
20.0
135
-------
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Turb JCU Median
34
Eco_
Level_
III
SEASON
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
65
71
71
71
71
72
72
72
72
74
74
74
74
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
18
18
21
15
17
2
2
3
2
5
5
5
3
22.9
2.42
7. 68
3.00
4.74
25.3
41.5
59.5
15.0
11.1
9.89
5.90
17.3
2.00
. 600
.900
.725
1.10
22.5
37.0
43.5
13.0
1.00
2.15
1.40
15.0
96.
4.
88.
16.
15.
28.
46.
84.
17.
17.
26.
12.
19.
,00
, 60
,80
,00
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,00
,00
,00
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,50
,50
,00
24.0
1.30
18.8
3.81
4.10
3.89
6.36
21.5
2.83
6.13
9.96
4.19
2.08
5.
0.
4.
0.
0.
2.
4.
12
2.
2.
4.
1.
1.
65
31
11
98
99
75
50
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00
74
46
87
20
105
54
245
127
86
15
15
36
19
55
101
71
12
2.00
0. 60
1.15
0.73
1.10
22.5
37.0
43.5
13.0
1.00
2.15
1.40
15.0
10.7
1.15
1.55
1.05
1.50
22.5
37.0
43.5
13.0
11.0
3.23
4.10
15.0
15.0
2.38
2.95
1.70
3.10
25.3
41.5
51.0
15.0
13.0
6.10
4.50
18.0
21.7
3. 60
4.18
3.35
6.40
28.0
46.0
84.0
17.0
13.0
11.5
7.00
19.0
96
4.
14
16
15
28
46
84
17
17
26
12
19
.0
60
.9
.0
.5
.0
.0
.0
.0
.5
.5
.5
.0
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Turb NTU Median
35
Eco_
Level_
III
SEASON
MEAN
MIN
MAX
STDDEV
STDERR
CV
P5
P25
MEDIAN
P75
P95
29
29
29
29
33
33
33
33
35
35
35
35
37
37
37
37
40
40
40
40
45
45
45
45
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
5
4
6
4
0
0
1
0
81
83
82
72
27
22
23
21
32
18
53
6
25
26
35
22
13.0
3.23
18.5
4.50
.
.
0.50
.
15. 6
27. 6
16.5
22.4
19.3
19.5
25.3
15.9
36.2
37.2
41.5
31.0
9.29
10.5
11.9
12.0
2.43
1.70
3.43
3.05
.500
2.15
2.25
3.55
3.48
2.20
4.80
2.15
4.10
3.00
16.5
4. 65
11.0
2.80
.900
1.70
4.35
48.
4.
70.
6.
0.
63.
175.
58.
150.
91.
52.
150.
50.
113.
80.
212.
55.
23.
28.
80.
42.
,50
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,00
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,00
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,75
,50
,50
,40
19.9
1.04
26.2
1.39
.
.
.
.
12.4
28.2
10.1
25.5
23.0
12.3
35.5
10.4
26.3
18.5
37.3
19. 6
5.52
7.07
13.3
8.39
8.
0.
10
0.
.
.
.
.
1.
3.
1.
3.
4.
2.
7.
2.
4.
4.
5.
8.
1.
1.
2.
1.
89
52
.7
69
38
09
12
00
42
63
41
28
64
35
13
01
10
39
24
79
153
32
141
31
.
.
.
.
80
102
61
114
119
63
140
66
72
50
90
63
59
67
112
70
2.
1.
3.
3.
.
.
0.
.
4.
8.
4.
6.
3.
6.
4.
6.
7.
16
5.
11
3.
1.
2.
4.
43
70
43
05
50
58
20
65
25
80
10
10
50
00
.5
80
.0
05
20
30
73
3.95
2. 60
4.48
3.48
.
.
0.50
.
7.80
12.5
8.80
10.2
5. 60
10.4
5.75
8.15
17.0
21.0
14.0
14.0
5.95
5.48
5.30
7.70
4.55
3. 60
5. 65
4.33
0.50
12.0
18.5
15.3
14.3
10.8
15. 6
11.5
13.5
25.5
33.5
32.0
25.5
8. 60
9.25
9.35
10.4
5.53
3.85
22.0
5.53
.
.
0.50
.
18.0
26.5
22.3
24.1
17.5
28.0
26.5
19.5
57.5
43.0
52.7
55.0
10.7
14.2
14.0
13.9
48.5
4.00
70.0
6.30
.
.
0.50
.
40.0
75.0
36.1
53.5
76.0
44.7
86.7
29.5
73.4
80.2
104
55.0
21.0
23.0
28.3
28.2
-------
64
64
64
64
65
65
65
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
20
21
33
15
115
152
173
4.75
6.98
6.42
7.25
10.8
17.8
17.3
.250
1.10
1.40
1.00
.250
.100
.250
19.00
27.00
16.90
32.75
71. 68
128.00
116.00
5.06
6.78
4.07
7.77
11.0
16.8
20. 6
1.13
1.48
0.71
2.01
1.03
1.36
1.57
106
97
63
107
102
94
119
0.25
1.30
1.80
1.00
1.25
1. 60
1.30
1. 63
2.75
3.05
2.90
4.10
7.41
6.00
2.43
4.30
5.10
5.18
7.10
14.0
10.2
6.85
7. 60
10.0
8.50
14.1
22.0
19.0
17.0
20.0
13.2
32.8
27.0
43.5
72.0
Aggregate Nutrient Ecoregion: IX
Rivers and Streams
Descriptive Statistics by Decade and Season
Parameter Turb NTU Median
36
Eco_
Level_
III
65
71
71
71
71
72
72
72
72
74
74
74
74
SEASON
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
FALL
SPRING
SUMMER
WINTER
N
133
45
34
47
33
6
3
5
2
10
16
18
15
MEAN
18.
11.
20.
19.
26.
28.
20.
23.
22.
23.
30.
41.
31.
,2
,8
,0
,0
,1
,7
,8
,7
,4
,4
,7
,9
,4
MIN
.250
.250
3.00
1.50
.250
10.0
17.0
.000
17.0
7. 60
4.00
5.00
10.0
MAX
84.00
82.75
72.75
199.90
125.53
64.00
26.00
50.25
27.75
39.25
90.00
130.00
93.50
STDDEV
16.5
13.9
17.8
29.9
28.7
19.9
4. 68
19.9
7. 60
11.2
22.3
36.9
21.2
STDERR
1.43
2.07
3.05
4.36
5.00
8.13
2.70
8.92
5.38
3.53
5.57
8. 69
5.48
CV
P5
P25
MEDIAN
P75
P95
91
117
89
157
110
69
23
84
34
48
73
88
67
1.
2.
3.
2.
5.
10
17
0.
17
7.
4.
5.
10
30
00
95
00
35
.0
.0
00
.0
60
00
00
.0
6.
4.
9.
4.
9.
13
17
13
17
14
17
15
17
40
60
00
95
50
.0
.0
.0
.0
.3
.0
.5
.5
14
7.
12
11
18
25
19
18
22
22
23
30
25
.0
55
.1
.5
.5
.0
.3
.0
.4
.5
.5
. 6
.0
25.
14.
25.
24.
26.
35.
26.
37.
27.
35.
38.
54.
37.
,0
,5
,5
,0
,1
,0
,0
,0
,8
,0
,3
,0
,2
50.
35.
63.
40.
,3
,3
,0
,0
108
64.
26.
50.
27.
39.
90.
,0
,0
,3
,8
,3
,0
130
93.
,5
-------
APPENDIX C
Quality Control/Quality Assurance Rules
-------
Support for the Compilation and Analysis of National Nutrient Data
15 Nutrient Ecoregion/Waterbody Type Summary Chapters
Prepared for:
Robert Cantilli
Environmental Protection Agency
OW/OST/HECD
Prepared by:
INDUS Corporation
1953 Gallows Road
Vienna, Virginia 22182
Contract Number: 68-C-99-226
Task Number: 04
Subtask Number: 4
August 8, 2000
-------
CONTENTS
1.0 BACKGROUND 1
1.1 Purpose 1
1.2 References 1
2.0 QA/QC PROCEDURES 2
2.1 National Data Sets 3
2.2 State Data 3
2.3 Laboratory Methods 4
2.4 Waterbody Name 4
2.5 Ecoregion Data 5
3.0 STATISTICAL ANALYSIS REPORTS 5
3.1 Data Source Reports 6
3.2 Remark Code Reports 7
3.3 Median of Each Waterbody 7
3.4 Descriptive Statistic Reports 7
3.5 Regression Models 8
4.0 TIME PERIOD 8
5.0 DATA SOURCES AND PARAMETERS FOR THE AGGREGATE NUTRIENT
ECOREGIONS 9
5.1 Lakes and Reservoirs 9
5.1.1 Aggregate Nutrient Ecoregion 2 9
5.1.2 Aggregate Nutrient Ecoregion 6 10
5.1.3 Aggregate Nutrient Ecoregion 7 10
5.1.4 Aggregate Nutrient Ecoregion 8 11
5.1.5 Aggregate Nutrient Ecoregion 9 12
5.1.6 Aggregate Nutrient Ecoregion 11 12
5.1.7 Aggregate Nutrient Ecoregion 12 13
5.1.8 Aggregate Nutrient Ecoregion 13 13
5.2 Rivers and Streams 14
5.2.1 Aggregate Nutrient Ecoregion 2 14
5.2.2 Aggregate Nutrient Ecoregion 3 15
5.2.3 Aggregate Nutrient Ecoregion 6 16
5.2.4 Aggregate Nutrient Ecoregion 7 16
5.2.5 Aggregate Nutrient Ecoregion 9 17
5.2.6 Aggregate Nutrient Ecoregion 11 18
5.2.7 Aggregate Nutrient Ecoregion 12 19
5.2.8 Aggregate Nutrient Ecoregion 14 20
-------
APPENDIX A Process Used to QA/QA the Legacy STORE! Nutrient Data Set
APPENDIX B Process for Adding Aggregate Nutrient Ecoregions and Level III
Ecoregions
APPENDIX C Glossary
in
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8, 2000
1.0 BACKGROUND
The Nutrient Criteria Program has initiated development of a national Nutrient Criteria Database
application that will be used to store and analyze nutrient data. The ultimate use of these data will
be to derive ecoregion- and waterbody-specific nutrient criteria ranges. EPA converted STOrage
and RETrieval (STORET) legacy data, National Stream Quality Accounting Network
(NASQAN) data, National Water-Quality Assessment (NAWQA) data, and other relevant
nutrient data from universities and States/Tribes into the database. The data imported into the
Nutrient Criteria Database will be used to develop national nutrient criteria ranges.
1.1 Purpose
The purpose of this deliverable is to provide EPA with information regarding the data used to
create the statistical reports which will be used to derive ecoregion- and waterbody-specific
nutrient criteria ranges for Level III ecoregions. There are fourteen aggregate nutrient
ecoregions. Each aggregate nutrient ecoregion is divided into smaller ecoregions referred to as
Level III ecoregions. EPA will determine criteria ranges for the waterbody types and Level III
ecoregions within the following aggregate nutrient ecoregions:
Lakes and Reservoirs
Aggregate Nutrient ecoregions: 2, 6, 7, 8, 9, 11, 12, 13
• Rivers and Streams
Aggregate Nutrient ecoregions: 2, 3, 6, 7, 9, 11, 12, 14
1.2 References
This section lists documents that contain baselines, standards, guidelines, policies, and references
that apply to the data analysis. Listed editions were valid at the time of publication. All
documents are subject to revision, but these specific editions govern the concepts described in this
document.
Nutrient Criteria Technical Guidance Manual: Lakes and Reservoirs (Draft). EPA, Office of
Water, EPA 822-D-99-001, April 1999.
Nutrient Criteria Technical Guidance Manual: Rivers and Streams (Draft). EPA, Office of
Water, EPA 822-D-99-003, September 1999.
Guidance for Data Quality Assessment: Practical Methods for Data Analysis. EPA, Office of
Research and Development, EPA QA/G-9, January 1998.
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8, 2000
2.0 QA/QC PROCEDURES
In order to develop nutrient criteria, EPA needed to obtain nutrient data from the states. EPA
requested nutrient data from the states and forwarded the data sets to INDUS via e-mail and/or
US mail. In addition, EPA tasked INDUS to convert data from three national data sets. EPA
provided INDUS with a Legacy STORET extraction to convert into the database. The United
States Geologic Survey (USGS) sent INDUS a CD-ROM with NASQAN data to convert.
INDUS downloaded NAWQA files from the USGS Web site to convert the data. In total,
INDUS converted and imported the following national and state data sets into the Nutrient
Criteria Database:
Legacy STORET
NAWQA
NASQAN
• Region 1
• Region 2 - Lake Champlain Monitoring Project
• Region 2 - NYSDEC Finger Lakes Monitoring Program
• Region 2 - NY Citizens Lake Assessment Program
• Region 2 - Lake Classification and Inventory Survey
Region 2 - NYCDEP (1990-1998)
Region 2 - NYCDEP (Storm Event data)
Region 2 - New Jersey Nutrient Data ( Tidal Waters)
• Region 5
• Region 3
• Region 3 - Nitrite Data
• Region 3 - Choptank River files
• Region 4 - Tennessee Valley Authority
• Region 7 - Central Plains Center for BioAssessment (CPCB)
Region 7 - REMAP
• Region 2 - Delaware River Basin Commission (1990-1998)
• Region 3 - PA Lake Data
• Region 3 - University of Delaware
• Region 10
• University of Auburn
As part of the conversion process, INDUS performed a number of Quality Assurance/Quality
Control (QA/QC) steps to ensure that the data was properly converted into the Nutrient Criteria
Database. Section 2 explains the steps performed by INDUS to convert the data.
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8, 2000
2.1 National Data Sets
INDUS converted three national data sets into the Nutrient Criteria Database: Legacy STORET
data, NASQAN data, and NAWQA data. A previous EPA contractor performed the extraction of
Legacy STORET data and documented the QA/QC procedures used on the data. This
documentation is included in Appendix A. INDUS performed minimal QA/QC on the Legacy
STORET data set because the previous contractor completed the steps outlined in Appendix A.
INDUS and EPA also agreed to convert the NAWQA and NASQAN data sets with minimal
QA/QC on the assumption that the source agency, the USGS, QA/QC'd the data.
For each of the three national data sets, INDUS ran queries to determine if 1) samples existed
without results and 2) if stations existed without samples. Per Task Order Project Officer
(TOPO) direction, these records were deleted from the system. For analysis purposes, EPA
determined that there was no need to keep station records with no samples and sample records
with no results. INDUS also confirmed that each data set contained no duplicate records.
In addition, INDUS deleted all composite results from the Legacy STORET data. Per TOPO
direction, it was decided that composite sample results would not be used in the statistical
analysis.
2.2 State Data
Each state data set was delivered in a unique format. Many of the data sets were delivered to
INDUS without corresponding documentation. INDUS analyzed each state data set in order to
determine which parameters should be converted for analysis. INDUS obtained a master
parameter table from EPA and converted the parameters in the state data sets according to those
that were present in the EPA parameter table. INDUS converted all of the data elements in the
state data sets that mapped directly to the Nutrient Criteria Database; data elements that did not
map to the Nutrient Criteria Database were not converted. In some cases, state data elements
that did not directly map into the Oracle database were inserted into a comment field within the
database. Also, INDUS maintained an internal record of which state data elements were inserted
into the comment field.
As part of the data clean-up efforts, INDUS determined whether or not there were any duplicate
records in the state data sets and deleted the duplicate records. INDUS checked the waterbody,
station, and sample entities for duplicate records. In addition, INDUS deleted station records
with no samples and sample records with no results. INDUS also deleted waterbody records that
were not associated with a station. In each case, INDUS maintained an internal record of how
many records were deleted.
If INDUS encountered referential integrity errors, such as samples that referred to stations that
did not exist, or if INDUS was unsure of whether a record was a duplicate, INDUS contacted the
agency directly via e-mail or phone to resolve any issues that arose. INDUS saved an electronic
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8, 2000
copy of each e-mail correspondence with the states to ensure that a record of the decision was
maintained. INDUS also contacted each agency to determine which laboratory methods were
used for each parameter.
Finally, INDUS examined the remark codes of each result record in the state data sets. INDUS
mapped the remark codes to the STORET remark codes listed in Table 2 of Appendix A. If any
of the state result records were associated with remark codes marked as "Delete" in Table 2 of
Appendix A, the result records were not converted into the database.
2.3 Laboratory Methods
Many of the state data sets did not contain laboratory method information. In addition, laboratory
method information was not available for the three national data sets. In order to determine
missing laboratory method information, EPA tasked another contractor to contact the data
owners to obtain the laboratory method. In some cases, the data owners responded and the
laboratory methods were added to the database.
2.4 Waterbody Name and Class Information
A large percentage of the data did not have waterbody-specific information. The only waterbody
information contained in the three national data sets was the waterbody name, which was
embedded in the station 'location description' field. Most of the state data sets contained
waterbody name information; however, much of the data was duplicated throughout the data sets.
Therefore, the waterbody information was cleaned manually. For the three national data sets, the
'location description' field was extracted from the station table and moved to a temporary table.
The 'location description' field was sorted alphabetically. Unique waterbodies were grouped
together based on name similarity and whether or not the waterbodies fell within the same county,
state, and waterbody type. Finally, the 'location description' field was edited to include only
waterbody name information, not descriptive information. For example, 110 MILE CREEK AT
POMONA DAM OUTFLOW, KS PO-2 was edited to 110 MILE CREEK. Also, if 100 MILE
CREEK was listed ten times in New York, but in four different counties, four 100 MILE CREEK
waterbody records were created.
Similar steps were taken to eliminate duplicate waterbody records in the state data sets. If a
number of records had similar waterbody names and fell within the same state, county, and
waterbody type, the records were grouped to create a unique waterbody record.
Most of the waterbody data did not contain depth, surface area, and volume measurements. EPA
needed this information to classify waterbody types. EPA attempted to obtain waterbody class
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8, 2000
information from the states. EPA sent waterbody files to the regional coordinators and requested
that certain class information be completed by each state. The state response was poor; therefore,
EPA was not able to perform statistical analysis for the waterbody types by class.
2.5 Ecoregion Data
Aggregate nutrient ecoregions and Level III ecoregions were added to the database using the
station latitude and longitude coordinates. If a station was lacking latitude and longitude
coordinates or county information, the data were not included in the statistical analysis. Appendix
B lists the steps taken to add the two ecoregion types (aggregate and Level III) to the Nutrient
Criteria Database. The ecoregion names were pulled from aggregate nutrient ecoregion and Level
III ecoregion Geographical Information System (GIS) coverages. In summary, the station latitude
and longitude coordinates were used to determine the ecoregion under the following
circumstances:
The latitude and longitude coordinates fell within the county/state listed in the station
table.
The county data was missing.
The county centroid was used to determine the ecoregions under the following circumstances:
The latitude and longitude coordinates were missing, but the state/county information was
available.
The latitude and longitude coordinates fell outside the county/state listed in the station
table. The county information was assumed to be correct; therefore, the county centroid
was used.
If the latitude and longitude coordinates fell outside the continental US county coverage file
(i.e., the point fell in the ocean or Mexico/Canada), the nearest ecoregion was assigned to the
station.
3.0 STATISTICAL ANALYSIS REPORTS
Aggregate nutrient ecoregion tables were created by extracting all observations for a specific
aggregate nutrient ecoregion from the nutrient criteria database. Then, the data were reduced to
create tables containing only the yearly median values. To create these tables, the median value
for each waterbody was calculated using all observations for each waterbody by Level III
ecoregion, year, and season. Tables of decade median values were created from the yearly
median tables by calculating the median for each waterbody by Level III ecoregion by decade and
season.
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8, 2000
The Data Source and the Remark Code reports were created using all observations (all reported
values). All the other reports were created from either the yearly median tables or the decade
median tables. In other words, the descriptive statistics and regressions were run using the
median values for each waterbody and not the individual reported values.
Statistical analyses were performed under the assumption that this data set is a random sample. If
this assumption cannot be verified, the observations may or may not be valid. Values below the
1st and 99th percentile were removed from the Legacy STORET database prior to the creation of
the national database. Also, data were treated according the Legacy STORET remark codes in
Appendix A.
The following contains a list of each report and the purpose for creating each report:
Data Source Created to provide a count of the amount of data and to identify the
source(s).
Remark Codes Created to provide a description of the data.
• Median of Each Waterbody by Year This was an intermediate step performed to obtain a
median value for each lake to be used in the yearly descriptive statistics reports and the
regression models.
Median of Each Waterbody by Decade This was an intermediate step performed to obtain
a median value for each lake to be used in the decade descriptive statistics.
Descriptive Statistics Created to provide EPA with the desired statistics for setting criteria
levels.
Regression Models Created to examine the relationships between biological and nutrient
variables.
Note: Separate reports were created for each season.
3.1 Data Source Reports
Data source reports were presented in the following formats:
• The number and percentage of data from each data source were summarized in tables for
each aggregate nutrient ecoregion by season and waterbody type.
The number and percentage of data from each data source were summarized in tables for
each Level III ecoregion by season and waterbody type.
The 'Frequency' represents the number of data values from a specific data source for each
parameter by data source. The 'Row Pet' represents the percentage of data from a specific data
source for each parameter.
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3.2 Remark Code Reports
Remark code reports were presented in the following formats:
• The number and percentage of data associated with a particular remark code for each
parameter were summarized in tables by Level III ecoregion by decade and season.
The number and percentage of data associated with a particular remark code for each
parameter were summarized in tables by Level III ecoregion by year and season.
The 'Frequency' represents the number of data values corresponding to the remark code in the
column. The 'Row Pet' represents the percentage of data that was associated with the remark
code in that row.
In the database, remark codes that were entered by the states were mapped to Legacy STORET
remark codes. Prior to the analysis, the data were treated according to these remark codes. For
example, if the remark code was 'K,' then the reported value was divided by two. Appendix A
contains a complete list of Legacy STORET remark codes.
Note: For the reports, a remark code of'Z' indicates that no remark codes were recorded. It does
not correspond to Legacy STORET code 'Z.'
3.3 Median of Each Waterbody
To reduce the data and to ensure heavily sampled waterbodies or years were not over represented
in the analysis, median value tables (described above) were created. The yearly median tables and
decade median tables were delivered to the EPA in electronic format as csv (comma separated
value or comma delimited) files.
3.4 Descriptive Statistic Reports
The number of waterbodies, median, mean, minimum, maximum, 5th, 25th , 75th , 95th
percentiles, standard deviation, standard error, and coefficient of variation were calculated. The
tables (described above) containing the decade median values for each waterbody for each
parameter were used to create descriptive statistics reports for:
• Level III ecoregions by decade and season
Aggregate nutrient ecoregions by decade and season
In addition, the tables containing the yearly median values for each waterbody for each parameter
were used to create descriptive statistics reports for:
• Level III ecoregions by year and season
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3.5 Regression Models
Simple linear regressions using the least squares method were performed to examine the
relationships between biological and nutrient variables in lakes and reservoirs, and rivers and
streams. Regressions were performed using the yearly median tables. Chlorophyll(s) in
micrograms per liter (ug/L), secchi in meters (m), dissolved oxygen in milligrams per liter (mg/L),
turbidity, and pH were the biological variables in these models. When there was little or no data
for chlorophyll, then pH or dissolved oxygen was substituted for chlorophyll. Secchi data were
used in the lake and reservoir models, and turbidity data were used in the river and stream models.
The nutrient variables in these models include: total phosphorus in ug/L, total nitrogen in mg/L,
total kjeldahl nitrogen in mg/L, and nitrate and nitrite in mg/L. Regressions were also run for
total nitrogen and total phosphorus for ecoregions where both these variables were measured.
Note: At the time of creation of this document only regressions for aggregate nutrient ecoregion 7
for lakes and reservoirs were delivered to the EPA. Regressions for the remaining aggregate
nutrient ecoregions will be delivered in August 2000.
4.0 TIME PERIOD
Data collected from January 1990 to December 1999 were used in the statistical analysis reports.
To capture seasonal differences, the data were classified as follows:
Aggregate nutrient ecoregions: 6, 7, and 8
Spring: April to May
Summer: June to August
Fall: September to October
Winter: November to March
• Aggregate nutrient ecoregions: 1, 2, 9, 10, 11, 12, and 13
Spring: March to May
Summer: June to August
Fall: September to November
Winter: December to February
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5.0 DATA SOURCES AND PARAMETERS FOR THE AGGREGATE NUTRIENT
ECOREGIONS
This section provides information for the nutrient aggregate ecoregions that were analyzed by
waterbody type. Each section lists the data sources for the aggregate nutrient ecoregion
including: 1) the data sources, 2) the parameters included in the analysis, and 3) the Level III
ecoregions within the aggregate nutrient ecoregions.
Note: For analysis purposes, the following parameters were combined to form Phosphorous,
Dissolved Inorganic (DIP):
Phosphorus, Dissolved Inorganic (DIP)
Phosphorus, Dissolved (DP)
Phosphorus, Dissolved Reactive (DRP)
Orthophosphate, dissolved, mg/L as P
Orthophosphate (OPO4_PO4)
5.1 Lakes and Reservoirs
5.1.1 Aggregate Nutrient Ecoregion 2
Data Sources:
Legacy STORE!
EPA Region 10
Parameter:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Phosphorus, Total Reactive (ug/L)
SECCHI (m)
pH
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Level III ecoregions:
1, 2, 4, 5, 9, 11, 15, 16, 17, 19, 21, 23, 41, 77, 78
5.1.2 Aggregate Nutrient Ecoregion 6
Data Sources:
Legacy STORE!
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level III ecoregions:
46, 47, 48, 54, 55, 57
5.1.3 Aggregate Nutrient Ecoregion 7
Data Sources:
LCMPD
Legacy STORET
NYCDEP
EPA Region 1
Parameters:
Chlorophyll A, Fluorometric Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
10
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Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level III ecoregions:
51, 52, 53, 56,60,61, 83
5.1.4 Aggregate Nutrient Ecoregion 8
Data Sources:
LCMPD
Legacy STORET
NYCDEP
NYCDEC
EPA Region 1
EPA Region 3
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B (ug/L)
Chlorophyll C (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level III ecoregions:
49, 50, 58, 62, 82
11
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5.1.5 Aggregate Nutrient Ecoregion 9
Data Sources:
Auburn University
Legacy STORE!
EPA Region 4
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Pheophytin (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level III ecoregions:
29, 33, 35, 37, 40, 45, 64, 65, 71, 72, 74
5.1.6 Aggregate Nutrient Ecoregion 11
Data Sources:
Auburn University
Legacy STORET
NYSDEC
EPA Region 3
EPA Region 4
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Pheophytin (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
12
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Chlorophyll A, Trichromatic, Uncorrected
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level III ecoregions:
36, 38, 39, 66, 67, 68, 69, 70
5.1.7 Aggregate Nutrient Ecoregion 12
Data Sources:
Legacy STORET
Parameters:
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level III ecoregions:
75
5.1.8 Aggregate Nutrient Ecoregion 13
Data Sources:
Legacy STORET
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Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level III ecoregions:
76
5.2 Rivers and Streams
5.2.1 Aggregate Nutrient Ecoregion 2
Data Sources:
Legacy STORET
NASQAN
NAWQA
EPA Region 10
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Phosphorus, Total (TP) Reactive (ug/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
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Turbidity (JCU)
Turbidity (NTU)
Level III ecoregions:
1, 2, 4, 5, 8, 9, 11, 15, 16, 17, 19, 21, 23, 41, 77, 78
5.2.2 Aggregate Nutrient Ecoregion 3
Data Sources:
Legacy STORET
NASQAN
NAWQA
EPA Region 10
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (JCU)
Turbidity (NTU)
Level III ecoregions:
6, 10, 12, 13, 14, 18, 20, 22, 24, 79, 80, 81
15
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5.2.3 Aggregate Nutrient Ecoregion 6
Data Sources:
Legacy STORET
NASQAN
NAWQA
EPA Region 5
EPA Region 7
Parameters:
Chlorophyll A, Fluorometric, Corrected
Chlorophyll A, Phytoplankton, Spectrophotometric Acid
Chlorophyll A, Phytoplankton, chromotographic- fluorometric
Chlorophyll A, Trichromatic, Uncorrected
Chlorophyll B, Phytoplankton, chromotographic- fluorometric
Phosphorous, Dissolved Inorganic (DIP)
Dissolved Oxygen (DO)
Nitrite and Nitrate, (NO2+NO3)
Nitrogen, Total (TN)
Nitrogen, Total Kjeldahl (TKN)
Organic, Phosphorus
Phosphorus, Total (TP)
Phosphorus, Orthophosphate, Total as P
Turbidity
Turbidity
Turbidity
Level III ecoregions:
46, 47, 48, 54, 55, 57
5.2.4 Aggregate Nutrient Ecoregion 7
Data Sources:
LCMPD
Legacy STORET
NASQAN
NAWQA
NYCDEP
August 8, 2000
(ug/L)
(ug/L)
(ug/L)
(ug/L)
(ug/L)
(ug/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(ug/L)
(ug/L)
(ug/L)
(FTU)
(JCU)
(NTU)
16
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Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Organic, Phosphorus (ug/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (JCU)
Turbidity (NTU)
Level III ecoregions:
51, 52, 53, 56,60,61, 83
5.2.5 Aggregate Nutrient Ecoregion 9
Data Sources:
Auburn University
Legacy STORET
NASQAN
NAWQA
EPA Region 3
EPA Region 5
EPA Region 7
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
August 8, 2000
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Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll B, Phytoplankton, Spectrophotometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Organic, Phosphorus (ug/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (JCU)
Turbidity (NTU)
Level III ecoregions:
29, 33, 35, 37, 40, 45, 64, 65, 71, 72, 74
5.2.6 Aggregate Nutrient Ecoregion 11
Data Sources:
Auburn University
Legacy STORET
NASQAN
NAWQA
EPA Region 3
EPA Region 5
EPA Region 7
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Organic, Phosphorus (ug/L)
August 8, 2000
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Phosphorus, Orthophosphate, Total as P (ug/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (JCU)
Turbidity (NTU)
Level III ecoregions:
36, 38, 39, 66, 67, 68, 69, 70
5.2.7 Aggregate Nutrient Ecoregion 12
Data Sources:
Legacy STORET
NASQAN
NAWQA
Parameters:
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, Spectrophotometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (NTU)
Level III ecoregions:
August 8, 2000
75
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5.2.8 Aggregate Nutrient Ecoregion 14
Data Sources:
Legacy STORE!
NASQAN
NAWQA
NYCDEP
EPA Region 1
EPA Region 3
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Nitrogen, Total (TN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (JCU)
Turbidity (NTU)
Level III ecoregions:
59, 63, 84
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APPENDIX A
Process Used to QA/QA the Legacy STORE! Nutrient Data Set
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1. STORET water quality parameters and Station and Sample data items were retrieved from
USEPA's mainframe computer. Table 1 lists all retrieved parameters and data items.
TABLE 1: PARAMETERS AND DATA ITEMS RETRIEVED FROM STORET
Parameters Retrieved
(STORET Parameter Code)
TN - mg/1 (600)
TKN - mg/1 (625)
Total Ammonia (NH3+NH4) - mg/1 (610)
Total NO2+NO3 - mg/1 (630)
Total Nitrite -mg/1 (6 15)
Total Nitrate - mg/1 (620)
Organic N - mg/L (605)
TP - mg/1 (665)
Chlor a - ug/L (spectrophotometric method,
32211)
Chlor a - ug/L (fluorometric method
corrected, 32209)
Chlor a - ug/L (trichromatic method
corrected, 32210)
Secchi Transp. - inches (77)
Secchi Transp. - meters (78)
+Turbidity JCUs (70)
+Turbidity FTUs (76)
+Turbidity NTUs field (82078)
+Turbidity NTUs lab (82079)
+DO - mg/L (300)
+Water Temperature (degrees C, 10/degrees
F, 11)
Station Data Items
Included
(STORET Item Name)
Station Type (TYPE)
Agency Code (AGENCY)
Station No. (STATION)
Latitude - std. decimal degrees
(LATSTD)
Longitude - std. decimal degrees
(LONGSTD)
Station Location (LOCNAME)
County Name (CONAME)
State Name (STNAME)
Ecoregion Name - Level III
(ECONAME)
Ecoregion Code -Level III
(ECOREG)
Station Elevation (ELEV)
Hydrologic Unit Code
(CATUNIT)
RF1 Segment and Mile
(RCHMIL)
RF ION/OFF tag (ONOFF)
Sample Data Items Included
(STORET Item Name)
Sample Date (DATE)
Sample Time (TIME)
Sample Depth (DEPTH)
Composite Sample Code
(SAMPMETH)
+ If data record available at a station included data only for this or other such marked parameters, data record was deleted
from data set.
The following set of retrieval rules were applied to the retrieval process:
Data were retrieved for waterbodies specified only as 'lake', 'stream', 'reservoir', or 'estuary'
under "Station Type" parameter. Any stations specified as 'well,' 'spring,' or 'outfall' were
eliminated from the retrieved data set.
Data were retrieved for station types described as 'ambient' (e.g., no pipe or facility
discharge data) under the "Station Type" parameter.
Data were retrieved that were designated as 'water' samples only. This includes 'bottom'
and 'vertically integrated' water samples.
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Data were retrieved that were designated as either 'grab' samples and 'composite' samples
(mean result only).
No limits were specified for sample depths.
Data were retrieved for all fifty states, Puerto Rico, and the District of Columbia.
The time period specified for data retrieval was January 1990 to September 1998.
No data marked as "Retired Data" (i.e., data from a generally unknown source) were
retrieved.
Data marked as "National Urban Runoff data" (i.e., data associated with sampling
conducted after storm events to assess nonpoint source pollutants) were included in the
retrieval. Such data are part of STORET's 'Archived' data.
Intensive survey data (i.e., data collected as part of specific studies) were retrieved.
Any values falling below the 1st percentile and any values falling above the 99th percentile
were transformed into 'missing' values (i.e., values were effectively removed from the data
set, but were not permanently eliminated).
Based on the STORET 'Remark Code' associated with each retrieved data point, the
following rules were applied (Table 2):
TABLE 2: STORET REMARK CODE RULES
STORET Remark Code
blank - Data not remarked.
A - Value reported is the mean of two or more
determinations.
B - Results based upon colony counts outside the acceptable
ranges.
C - Calculated. Value stored was not measured directly, but
was calculated from other data available.
D - Field measurement.
Keep or Delete Data Point
Keep
Keep
Delete
Keep
Keep
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E - Extra sample taken in compositing process.
F - In the case of species, F indicates female sex.
G - Value reported is the maximum of two or more
determinations.
H - Value based on field kit determination; results may not
be accurate.
I - The value reported is less than the practical
quantification limit and greater than or equal to the method
detection limit.
J - Estimated. Value shown is not a result of analytical
measurement.
K - Off-scale low. Actual value not known, but known to be
less than value shown.
L - Off-scale high. Actual value not known, but known to
be greater than value shown.
M - Presence of material verified, but not quantified.
Indicates a positive detection, at a level too low to permit
accurate quantification.
N - Presumptive evidence of presence of material.
O - Sample for, but analysis lost. Accompanying value is
not meaningful for analysis.
P - Too numerous to count.
Q - Sample held beyond normal holding time.
R - Significant rain in the past 48 hours.
S - Laboratory test.
T - Value reported is less than the criteria of detection.
Delete
Delete
Delete
Delete
Keep, but used one-half the reported value as the new value.
Delete
Keep, but used one-half the reported value as the new value.
Keep
Keep, but used one half the reported value as the new value.
Delete
Delete
Delete
Delete
Delete
Keep
Keep, but replaced reported value with 0.
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August 8, 2000
U - Material was analyzed for, but not detected. Value
stored is the limit of detection for the process in use.
V - Indicates the analyte was detected in both the sample
and associated method blank.
W - Value observed is less than the lowest value reportable
under remark "T."
X - Value is quasi vertically-integrated sample.
Y - Laboratory analysis from unpreserved sample. Data
may not be accurate.
Z - Too many colonies were present to count.
Keep, but replaced reported value with 0.
Delete
Keep, but replaced reported value with 0.
No data point with this remark code in data set.
Delete
Delete
If a parameter (excluding water temperature) value was less than or equal to zero and no remark code was present, the value
was transformed into a missing value.
Rationale - Parameter concentrations should never be zero without a proper explanation. A method detection limit should
at least be listed.
4. Station records were eliminated from the data set if any of the following descriptors were
present within the "Station Type" parameter:
MONITR - Source monitoring site, which monitors a known problem or
to detect a specific problem.
HAZARD - Site of hazardous or toxic wastes or substances.
ANPOOL - Anchialine pool, underground pools with subsurface
connections to watertable and ocean.
DOWN - Downstream (i.e., within a potentially polluted area) from a
facility which has a potential to pollute.
IMPDMT - Impoundment. Includes waste pits, treatment lagoons, and
settling and evaporation ponds.
STMSWR - Storm water sewer.
LNDFL - Landfill.
CMBMI - Combined municipal and industrial facilities.
CMBSRC - Combined source (intake and outfall).
Rationale - these descriptors potentially indicate a station location that at which an
ambient water sample would not be obtained (i.e., such sampling locations are potentially
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biased) or the sample location is not located within one of the designated water body types (i.e,
ANPOOL).
5. Station records were eliminated from data set if the station location did not fall within any
established cataloging unit boundaries based on their latitude and longitude.
6. Using nutrient ecoregion GIS coverage provided by USEPA, all station locations with
latitude and longitude coordinates were tagged with a nutrient ecoregion identifier
(nutrient region identifiers are values 1 - 14) and the associated nutrient ecoregion name.
Because no nutrient ecoregions exist for Alaska, Hawaii, and Puerto Rico, stations located
in these states were tagged with "dummy" nutrient ecoregion numbers (20 = Alaska, 21 =
Hawaii, 22 = Puerto Rico).
7. Using information provided by TV A, 59 station locations that were marked as 'stream'
locations under the "Station Type" parameter were changed to 'reservoir' locations.
8. The nutrient data retrieved from STORET were assessed for the presence of duplicate
data records. The duplicate data identification process consisted of three steps: 1)
identification of records that matched exactly in terms of each variable retrieved; 2)
identification of records that matched exactly in terms of each variable retrieved except for
their station identification numbers; and 3) identification of records that matched exactly in
terms of each variable retrieved except for their collecting agency codes. The data
duplication assessment procedures were conducted using SAS programs.
Prior to initiating the data duplication assessment process, the STORET nutrient data set
contained:
41,210 station records
924,420 sample records
Identification of exactly matching records
All data records were sorted to identify those records that matched exactly. For
two records to match exactly, all variables retrieved had to be the same. For
example, they had to have the same water quality parameters, parameter results
and associated remark codes, and have the same station data item and sample data
item information. Exactly matching records were considered to be exact
duplicates, and one duplicate record of each identified matching set were
eliminated from the nutrient data set. A total of 924 sample records identified as
duplicates by this process were eliminated from the data set.
Identification of matching records with the exception of station identification
number
All data records were sorted to identify those records that matched exactly except
for their station identification number (i.e., they had the same water quality
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parameters, parameter results and associated remark codes, and the same station
and sample data item information with the exception of station identification
number). Although the station identification numbers were different, the latitude
and longitude for the stations were the same indicating a duplication of station data
due to the existence of two station identification numbers for the same station. For
each set of matching records, one of the station identification numbers was
randomly selected and its associated data were eliminated from the data set. A
total of 686 sample records were eliminated from the data set through this process.
• Identification of matching records with the exception of collecting agency codes
All data records were sorted to identify those records that matched exactly except
for their collecting agency codes (i.e., they had the same water quality parameters,
parameter results and associated remark codes, and the same station and sample
data item information with the exception of agency code). The presence of two
matching data records each with a different agency code attached to it suggested
that one agency had utilized data collected by the other agency and had entered the
data into STORET without realizing that it already had been placed in STORET
by the other agency. No matching records with greater than two different agency
codes were identified. For determining which record to delete from the data set,
the following rules were developed:
> If one of the matching records had a USGS agency code, the USGS
record was retained and the other record was deleted.
> Higher level agency monitoring program data were retained. For
example, federal program data (indicated by a " 1" at the beginning
of the STORET agency code) were retained against state (indicated
by a "2") and local (indicated by values higher than 2) program
data.
> If two matching records had the same level agency code, the record
from the agency with the greater number of overall observations
(potentially indicating the data set as the source data set) was
retained.
A total of 2,915 sample records were eliminated through this process.
As a result of the duplicate data identification process, a total of 4,525 sample records and
36 individual station records were removed from the STORET nutrient data set. The
resulting nutrient data set contains the following:
41,174 station records
919,895 sample records
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APPENDIX B
Process for Adding Aggregate Nutrient Ecoregions and Level III Ecoregions
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Steps for assigning Level III ecoregions and aggregate nutrient ecoregion codes and names to the
Nutrient Criteria Database (performed using ESRI's ARCView v 3.2 and its GeoProcessing
Wizard). This process is performed twice; once for the Level III ecoregions and once for the
aggregate nutrient ecoregions:
Add the station .dbf data table, with latitude and longitude data, to project by 'Add
Event Theme'
Convert to the shapefile format
Create 'stcojoin' field, populate the 'stcojoin' field with the following formula:
'County.LCase+State.LCase'
Add field 'stco_flag' to the station shapefile
Spatially join the station data with the county shapefile (cntysjned.shp)
Select 'stcojoin' (station shapefile) field = 'stcojoin2' (county shapefile) field
Calculate stco_flag = 0 for selected features
Step through all blank stco_flag records, assign the appropriate stco_flags, see list
on the following page
Select all stco_flags = 4 or 7, switch selection
Calculate ctyfips (station) to cntyfips (county)
Stop editing and save edits, remove all joins
Add in 2 new fields 'x-coordl' and 'y-coordl' into station table
Select all stco_flags =1,2, and 6
Link county coverage with station coverage
Populate 'x-coordl' and 'y-coordl' with 'x-coord' and 'y-coord' from county
coverage
Select all stco_flags = 1, 2, and 6, export to new .dbf file
Add new .dbf file as event theme
Convert to shapefile format
Add the following fields to both tables (original station and station!26 shapefiles):
'eco_omer', 'name_omer', 'dis_aggr', 'code_aggr', 'name_aggr'
Spatially join station 126 and eco-omer coverage
Populate the 'eco_omer' field with the 'eco' value
Repeat the previous step using the nearest method (line coverage) to determine
ecoregion assignment for the line coverage, if some records are blank
Spatially join the ecoregion line coverage to station coverage, link the LPoly#
(from the spatially joined table) to Poly# (of the ecoregion polygon coverage)
Populate the Eco fields with the appropriate information.
Follow the same steps to the Rpoly#
Remove all table j oins
Link the useco-om table with station!26 table and populate 'name-omer' field
Spatially join station aggr coverage and populate the rest of the fields. Follow the
same procedures as outlined above
Remove all joins
Make sure the new Eco field added into the station 126 shapefile are different than
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8, 2000
the ones in the original station shapefile
Join station 126 and station coverage by station-id
Populate all the Eco fields in the original station coverage
Remove all joins
Save table
Make sure that all ctyfips records are populated; the county shapefile may have to
be joined to populate the records, if the stco_flag = 4
Create 2 new fields, 'NewCounty' and 'NewState'
Populate these new fields with a spatial join to the county coverage
Select by feature (ecoregion shapefile) all of the records in the station shapefile
Switch selection (to get records outside of the ecoregion shapefile)
If any of the selected records have stco_flag = 0 (they are outside the ecoregion
shapefile boundary), calculate them to stco_flag = 3
stco_flags (state/county flags in order of importance)
0 The state and county values from the data set matched the state and county values
from the spatial join.
(Ecoregions were assigned based on the latitude/longitude coordinates.)
1 The state and county values from the data set did not match the state and county
values from the spatial join, but the point was inside the county coverage
boundary.
(Ecoregions were assigned based on the county centroid.)
2 The state and county values from the data set did not match the state and county
values from the spatial join because the point was outside the county coverage
boundary; therefore, there was nothing to compare to the point (i.e., the point
falls in the ocean/Canada/Mexico). This occurred for some coastal samples.
(Ecoregions were assigned based on the county centroid.)
3 The state and county values from the data set matched the state and county from
the spatial join, but the point was outside the ecoregion boundary.
(Ecoregions were assigned to the closest ecoregion to the point.)
(No ecoregions were assigned to AK, HI, PR, BC, and GU.)
4 Latitude/longitude coordinates were provided, but there was no county
information.
(Ecoregions were assigned based on the latitude/longitude coordinates.)
5 The state and county values from the data set did not match the state and county
values from the spatial join due to spelling or naming convention errors.
The matches were performed manually.
(Ecoregions were assigned based on the latitude/longitude coordinates.)
6 No latitude/longitude coordinates were provided, only state and county
information was available.
(Ecoregions were assigned based on the county centroid.)
7 No latitude/longitude coordinates were provided, only state information was
available; therefore, no matches were possible.
(Ecoregions were not assigned. Data is not included in the analysis.)
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APPENDIX C
Glossary
Coefficient of Variation- Equal to the standard deviation divided by the mean multiplied by 100.
Maximum- The highest value.
Mean- The arithmetic average.
Median- The 50th percentile or middle value. Half of the values are above the median, and half of
the values are below the median.
Minimum- The lowest value.
Standard Deviation- Equal to the square root of the variance with the variance defined as the sum
of the squared deviations divided by the sample size minus one.
Standard Error- Standard error of the mean is equal to the standard deviation divided by the
square root of the sample size.
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INDUS
CORPORATION
Knowledge-Based Sol Lilians
Support for the Compilation and Analysis of
National Nutrient Data
15 Nutrient Ecoregion/Waterbody Type Summary
Chapters ..
Prepared for:
Robert Cantilli
Environmental Protection Agency
OW/OST/HECD
Prepared by: .
INDUS Corporation
1953 Gallows Road
Vienna, Virginia 22182
Contract Number: 68-C-99-226
Task Number: . 04
Subtask Number: . 4
August 8, 2000
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15 Nutrient Ecoregion/ Waterbody Type Summary Chapters. Contract # 68-C-99-226, TO# 04 August 8, 2000 ,
CONTENTS
1.0 BACKGROUND 1
1.1 Purpose 1
1.2 References .1
2.0 QA/QC PROCEDURES 2
2.1 National Data Sets 3
2.2 State Data 3
2.3 Laboratory Methods 4
2.4 Waterbody Name '. 4
2.5 Ecoregion Data 5
3.0 STATISTICAL ANALYSIS REPORTS 5
3.1 Data Source Reports 6
3.2 Remark Code Reports 7
3.3 Median of Each Waterbody 7
3.4 Descriptive Statistic Reports 7
3.5 Regression Models 8
4.0 TIME PERIOD 8
5.0 DATA SOURCES AND PARAMETERS FOR THE AGGREGATE NUTRIENT
ECOREGIONS 9
5.1 Lakes and Reservoirs 9
5.1.1 Aggregate Nutrient Ecoregion 2 9
5.1.2 Aggregate Nutrient Ecoregion 6 10
5.1.3 Aggregate Nutrient Ecoregion 7 10
5.1.4 Aggregate Nutrient Ecoregion 8 11
5.1.5 Aggregate Nutrient Ecoregion 9 12
5.1.6 Aggregate Nutrient Ecoregion 11 12
5.1.7 Aggregate Nutrient Ecoregion 12 .- 13
5.1.8 Aggregate Nutrient Ecoregion 13 13
5.2 Rivers and Streams 14
5.2.1 Aggregate Nutrient Ecoregion 2 14
5.2.2 Aggregate Nutrient Ecoregion 3 15
5.2.3 Aggregate Nutrient Ecoregion 6 16
5.2.4 Aggregate Nutrient Ecoregion 7 16
5.2.5 Aggregate Nutrient Ecoregion 9 17
5.2.6 Aggregate Nutrient Ecoregion 11 18
5.2.7 Aggregate Nutrient Ecoregion 12 19
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5.2.8 Aggregate Nutrient Ecoregion 14 20
APPENDIX A Process Used to QA/QA the Legacy STORE! Nutrient Data Set
APPENDIX B Process for Adding Aggregate Nutrient Ecoregions and Level m
Ecoregions
APPENDIX C Glossary
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1.0 BACKGROUND
The Nutrient Criteria Program has initiated development of a national Nutrient Criteria Database
application that will be used to store and analyze nutrient data. The ultimate use of these data
will be to derive ecoregion- and waterbody-specific nutrient criteria ranges. EPA converted
STOrage and RETrieval (STORET) legacy data, National Stream Quality Accounting Network
(NASQAN) data, National Water-Quality Assessment (NAWQA) data, and other relevant
nutrient data from universities and States/Tribes into the database. The data imported into the
Nutrient Criteria Database will be used to develop national nutrient criteria ranges.
1.1 Purpose
The purpose of this deliverable is to provide EPA with information regarding the data used to
create the statistical reports which will be used to derive ecoregion- and waterbody-specific
nutrient criteria ranges for Level HI ecoregions. There are fourteen aggregate nutrient
ecoregions. Each aggregate nutrient ecoregion is divided into smaller ecoregions referred to as
Level HI ecoregions. EPA will determine criteria ranges for the waterbody types and Level HI
ecoregions within the following aggregate nutrient ecoregions:
• Lakes and Reservoirs
Aggregate Nutrient ecoregions: 2,6,7, 8,9,11,12,13
• Rivers and Streams
- Aggregate Nutrient ecoregions: 2,3,6, 7,9, 11, 12, 14
1.2 References
This section lists documents that contain baselines, standards, guidelines, policies, and references
that apply to the data analysis. Listed editions were valid at the time of publication. All
documents are subject to revision, but these specific editions govern the concepts described in
this document.
Nutrient Criteria Technical Guidance Manual: Lakes and Reservoirs (Draft).- EPA, Office of
Water, EPA 822-D-99-001, April 1999.
Nutrient Criteria Technical Guidance Manual: Rivers and Streams (Draft). EPA. Office of
Water. EPA 822-D-99-003, September 1999.
Guidance for Data Quality Assessment: Practical Methods for Data Analysis. EPA, Office of
Research and Development, EPA-QA/G-9, January 1998.
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15 Nutrient Ecorcgion/Waterbody Type Summary Chapters, Contract # 68-C-99-226. TO# 04 August 8, 2000
2.0 QA/QC PROCEDURES
In order to develop nutrient criteria, EPA needed to obtain nutrient data from the states. EPA
requested nutrient data from the states and forwarded the data sets to INDUS via e-mail and/or
US mail. In addition, EPA tasked INDUS to convert data from three national data sets. EPA
provided INDUS with a Legacy STORET extraction to convert into the database. The United '
States Geologic Survey (USGS) sent INDUS a CD-ROM with NASQAN data to convert.
INDUS downloaded NAWQA files from the USGS Web site to convert the data. In total,
INDUS converted and imported the following national and state data sets into the Nutrient
Criteria Database:
Legacy STORET
NAWQA
NASQAN
• Region I
• Region 2 - Lake Champlain Monitoring Project
Region 2 - NYSDEC Finger Lakes Monitoring Program
• Region 2 - NY Citizens Lake Assessment Program
• Region 2 - Lake Classification and Inventory Survey
Region 2 - NYCDEP (1990-1998)
Region 2 - NYCDEP (Storm Event data)
• Region 2 - New Jersey Nutrient Data (Tidal Waters)
• RegionS
• RegionS.
• Region 3 - Nitrite Data
• Region 3 - Choptank River files
• Region 4 - Tennessee Valley Authority '
Region 7 - Central Plains Center for BioAssessment (CPCB)
Region 7 - REMAP
Region 2 - Delaware River Basin Commission (1990-1998)
Region 3 - PA Lake Data
• RegionS-University of Delaware
• Region 10 .
• University of Auburn
As part of the conversion process, INDUS performed a number of Quality Assurance/Quality
Control (QA/QC) steps to ensure that the data was properly convened into the Nutrient Criteria
Database. Section 2 explains the steps performed by INDUS to convert the data.
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! 5 Nutrient Ecoregiorv Waterbody Type Summary Chapters. Contract # 68-C-99-226, TOtt 04 August 8. 2000
2.1 National Data Sets
INDUS converted three national data sets into the Nutrient Criteria Database: Legacy STORET
data, NASQAN data, and NAWQA data. A previous EPA contractor performed the extraction of
Legacy STORET data and documented the QA/QC procedures used on the data. This
documentation is included in Appendix A. INDUS performed minimal QA/QC on the Legacy
STORET data set because the previous contractor completed the steps outlined in Appendix A.
INDUS and EPA also agreed to convert the NAWQA and NASQAN data sets with minimal
QA/QC on the assumption that the source agency, the USGS, QA/QC'd the data.
For each of the three national data sets, INDUS ran queries to determine if 1) samples existed
without results and 2) if stations existed without samples. Per Task Order Project Officer
(TOPO) direction, these records were deleted from the system. For analysis purposes, EPA
determined that there was no need to keep station records with no samples and sample records
with no results. INDUS also confirmed that each data set contained no duplicate records.
In addition, INDUS deleted all composite results from the Legacy STORET data. Per TOPO
direction, it was decided that composite sample results would not be used in the statistical
analysis.
2.2 State Data
Each state data set was delivered in a unique format. Many of the data sets were delivered to
INDUS without corresponding documentation. INDUS analyzed each state data set in order to
determine which parameters should be converted for analysis. INDUS obtained a master
parameter table from EPA and converted the parameters in the state data sets according to those
that were present in the EPA parameter table. INDUS converted all of the data elements in the
state data sets that mapped directly to the Nutrient Criteria Database; data elements that did not ,
"map to the Nutrient Criteria Database were not converted. In some cases, state data elements that
did not directly map into the Oracle database were inserted into a comment field within the
database. Also, INDUS maintained an internal record of which state data elements were inserted
into the comment field.
As part of the data clean-up efforts, INDUS determined whether or not there were any duplicate
records in the state data sets and deleted the duplicate records. INDUS checked the waterbody,
station, and sample entities for duplicate records. In addition, INDUS deleted station records
with no samples and sample records with no results. INDUS also deleted waterbody records that
were not associated with a station. In each case, INDUS maintained an internal record of how
many records were deleted.-
If INDUS encountered referential integrity errors, such as samples that referred to stations that
did not exist, or if INDUS was unsure of whether a record was a duplicate, INDUS contacted the
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226. TO# 04 August 8, 2000 •
agency directly via e-mail or phone to resolve any issues that arose. INDUS saved an electronic
copy of each e-mail correspondence with the states to ensure that a record of the decision was
maintained. INDUS also contacted each agency to determine which laboratory methods were
used for each parameter.
Finally, INDUS examined the remark codes of each result record in the state data sets. INDUS
mapped the remark codes to the STORET remark codes listed in Table 2 of Appendix A. If any
of the state result records were associated with remark codes marked as "Delete" in Table 2 of
Appendix A, the result records were not converted into the database.
2.3 Laboratory Methods
Many of the state data sets did not contain laboratory method information. In addition,
laboratory method information was not available for the three national data sets. In order to
determine missing laboratory method information, EPA tasked another contractor to contact the
data owners to obtain the laboratory method. In some cases, the data owners responded and the
laboratory methods were added to the database.
2.4 Waterbody Name and Class Information
A large percentage of the data did not have waterbody-specific information. The only waterbody
information contained in the three national data sets was the waterbody name, which was
embedded in the station 'location description' field. Most of the state data sets contained
waterbody name information; however, much of the data was duplicated throughout the data sets.
Therefore, the waterbody information was cleaned manually. For the three national data sets, the
'location description' field was extracted from the station table and moved to a temporary table.
The 'location description' field was sorted alphabetically. Unique waterbodies were grouped
together based on name similarity and whether or not the waterbodies fell within the same .
county, state, and waterbody type. Finally, the 'location description' field was edited to include
only waterbody name information, not descriptive information. For example, 110 MILE CREEK
AT POMONA DAM OUTFLOW, KS PO-2 was edited to 110 MILE CREEK. Also, if 100
MILE CREEK was listed ten times in New York, but in four different counties, four 100 MILE
CREEK waterbody records were created.
Similar steps were taken to eliminate duplicate waterbody records in the state data sets. If a
number of records had similar waterbody names and fell within the same state, county, and
waterbody type, the records were grouped to create a unique waterbody record.
Most of the waterbody data-did not contain depth, surface area, and volume measurements. EPA
needed this information to classify waterbody types. EPA attempted to obtain waterbody class
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226. TO# 04 August 8,2000
information from the states. EPA sent waterbody files to the regional coordinators and requested
that certain class information be completed by each state. The state response was poor; therefore,
EPA was not able to perform statistical analysis for the waterbody types by class.
2.5 Ecoregion Data
Aggregate nutrient ecoregions and Level HI ecoregions were added to the database using the
station latitude and longitude coordinates. If a station was lacking latitude and longitude
coordinates or county information, the data were not included in the statistical analysis.
Appendix B lists the steps taken to add the two ecoregion types (aggregate and Level HI) to the
Nutrient Criteria Database. The ecoregion names were pulled from aggregate nutrient ecoregion
and Level HI ecoregion Geographical Information System (GIS) coverages. In summary, the
station latitude and longitude coordinates were used to determine the ecoregion under the
following circumstances:
The latitude and longitude coordinates fell within the county/state listed in the station
table.
The county data was missing.
•
The county centroid was used to determine the ecoregions under the following circumstances:
• The latitude and longitude coordinates were missing, but the state/county information was
available.
• The latitude and longitude coordinates fell outside the county/state listed in the station
table. The county information was assumed to be correct; therefore, the county centroid
was used. .
If the latitude and longitude coordinates fell outside the continental US county coverage file
(i.e., the point fell in the ocean or Mexico/Canada), the nearest ecoregion was assigned to the
station.
3.0 STATISTICAL ANALYSIS REPORTS
Aggregate nutrient ecoregion tables were created by extracting all observations for a specific
aggregate nutrient ecoregion from the nutrient criteria database. Then, the data were reduced to
create tables containing only the yearly median values. To create these tables, the median value
for each waterbody was calculated using all observations for each waterbody by Level III
ecoregion, year, and season. Tables of decade median values were created from the yearly
median tables by calculating the median for each waterfaody by Lsvel IE ecoregion by decade and
seasonv
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The Data Source and the Remark Code reports were created using all observations (all reported
values). All the other reports were created from either the yearly median tables or the decade
median tables. In other words, the descriptive statistics and regressions were run using the
median values for each waterbody and not the individual reported values.
Statistical analyses were performed under the assumption that this data set is a random sample.
If this-assumption cannot be verified, the observations may or may not be valid. Values below
the 1st and 99th percentile were removed from the Legacy STORET database prior to the creation
of the national database. Also, data were treated according the Legacy STORET remark codes in
Appendix A.
The following contains a list of each report and the purpose for creating each report:
• Data Source—Created to provide a count of the amount of data and to identify the
source(s).
• Remark Codes—Created to provide a description of the data.
Median of Each Waterbody by Year—This was an intermediate step performed to obtain
a median value for each lake to be used in the yearly descriptive statistics reports and the
regression models.
• Median of Each Waterbody by Decade—This was an intermediate step performed to
obtain a median value for each lake to be used in the decade descriptive statistics.
• Descriptive Statistics—Created to provide EPA with the desired statistics for setting
criteria levels.
• Regression Models—Created to examine the relationships between biological and
nutrient variables.
Note: Separate reports were created for each season.
t
3.1 Data Source Reports
Data source reports were presented in the following formats:
• The number and percentage of data from each data source were summarized in tables for
each aggregate nutrient ecoregion by season and waterbody type.
• The number and percentage of data from each data source were summarized in tables for
each Level III ecoregion by season and waterbody type.
The 'Frequency' represents" the number of data values from a specific data source for each
parameter by data source. The 'Row Pet' represents the percentage of data from a specific data
source for each parameter.
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3.2 Remark Code Reports
Remark code reports were presented in the following formats:
• The number and percentage of data associated with a particular remark code for each
parameter were summarized in tables by Level HI ecoregion by decade and season.
• The number and percentage of data associated with a particular remark code for each
parameter were summarized in tables by Level in ecoregion by year and season.
The 'Frequency' represents the number of data values corresponding to the remark code in the
column. The 'Row Pet' represents the percentage of data that was associated with the remark
code in that row.
In the database, remark codes that were entered by the states were mapped to Legacy STORET
remark codes. Prior to the analysis, the data were treated according to these remark codes. For
example, if the remark code was 'K,' then the reported value was divided by two. Appendix A
contains a complete list of Legacy STORET remark codes.
Note: For the reports, a remark code of 'Z' indicates that no remark codes were recorded. It does
not correspond to Legacy STORET code 'Z.'
3.3 Median of Each Waterbody
To reduce the data and to ensure heavily sampled waterbodies or years were not over represented
in the analysis, median value tables (described above) were created. The yearly median tables
and decade median tables were delivered to the EPA in electronic format as csv (comma
separated value or comma delimited) files.
3.4 Descriptive Statistic Reports
The number of waterbodies, median, mean, minimum, maximum, 5th, 25th, 75th, 95th percentiles,
standard deviation, standard error, and coefficient of variation were calculated. The tables
(described above) containing the decade median values for each waterbody for each parameter
were used to create descriptive statistics reports for:
• Level IE ecoregions by decade and season
• Aggregate nutrient ecoregions by decade and season
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15 Nument Ecoregion/Waterbody Type Summary Chapters. Contract tt 68-C-99-226, TO# 04 August 8, 2000
In addition, the tables containing the yearly median values for each waterbody for each parameter
were used to create descriptive statistics reports for:
• Level El ecoregions by year and season
3.5 Regression Models
Simple linear regressions using the least squares method were performed to examine the
relationships between biological and nutrient variables in lakes and reservoirs, and rivers and
streams. Regressions were performed using the yearly median tables. Chlorophyll(s) in
micrograms per liter (ug/L), secchi in meters (m), dissolved oxygen in milligrams per liter
(mg/L), turbidity, and pH were the biological variables in these models. When there was little or
no data for chlorophyll, then pH or dissolved oxygen was substituted for chlorophyll. .Secchi-
data were used in the lake and reservoir models, and turbidity data were used in the river and
stream models. The nutrient variables in these models include: total phosphorus in ug/L, total
nitrogen in mg/L, total kjeldahl nitrogen in mg/L, and nitrate and nitrite in mg/L, Regressions
were also run for total nitrogen and total'phosphorus for ecoregions where both these variables
were measured.
Note: At the time of creation of this document only regressions for aggregate nutrient ecoregion 7
for lakes and reservoirs were delivered to the EPA. Regressions for the remaining aggregate
nutrient ecoregions will be delivered in August 2000.
4.0 TIME PERIOD
Data collected from January 1990 to December 1999 were used in the statistical analysis reports.
To capture seasonal differences, the data were classified as follows: • ,
• Aggregate nutrient ecoregions: 6, 7, and 8
- Spring: April to May
- Summer: June to August
- Fall: September to October
- Winter: November to March
• Aggregate nutrient ecoregions: 1,2. 9. 10, 11,12, and 13
- Spring: - March to May
- Summer: June to August
Fall: September to November
Winter: December to February
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15 Nutrient Ecoregion/ Waterbody Type Summary Chapters, Contract» 68-C-99-226. TO# 04 August 8,2000
5.0 DATA SOURCES AND PARAMETERS FOR THE AGGREGATE NUTRIENT
ECOREGIONS
This section provides information for the nutrient aggregate ecoregions that were analyzed by
waterbody type. Each section lists the data sources for the aggregate nutrient ecoregion
including: 1) the data sources, 2) the parameters included in the analysis, and 3) the Level HI
ecoregions within the aggregate nutrient ecoregions.
Note: For analysis purposes, the following parameters were combined to form Phosphorous,
Dissolved Inorganic (DIP):
Phosphorus, Dissolved Inorganic (DIP)
Phosphorus, Dissolved (DP)
Phosphorus, Dissolved Reactive (DRP)
Orthophosphate, dissolved, mg/L as P
Orthophosphate (OPO4JPO4)
5.1 Lakes and Reservoirs
5.1.1 Aggregate Nutrient Ecoregion 2
Data Sources:
Legacy STORE!
EPA Region 10
Parameter:
i
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Phosphorous. Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus. Total (TP) (ug/L)
Phosphorus. Total Reactive (ug/L)
SECCHI " (m)
PH
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15 Nument Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8.2000'
Level in ecoregions:
1, 2,4, 5, 9, 11, 15, 16, 17, 19, 21, 23, 41, 77, 78
5.1.2 Aggregate Nutrient Ecoregion 6
Data Sources:
Legacy STORE!
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level Hf ecoregions:
46,47,48,54,55,57
5.1.3 Aggregate Nutrient Ecoregion 7
»
Data Sources:
LCMPD
Legacy STORET
NYCDEP
EPA Region I
Parameters:
Chlorophyll A, Fluorometric Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton. Spectrophotometric. Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
10
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters. Contract # 68-C-99-226, TO# 04 August 8. 2000-
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level HI ecoregions:
51,52,53,56,60,61,83
5.1.4 Aggregate Nutrient Ecoregion 8
Data sources:
LCMPD
Legacy STORET
NYCDEP
NYCDEC
EPA Region 1
EPA Region 3
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotorhetric Acid (ug/L)
Chlorophyll A. Phytoplankton, Spectrophotometric, Uncbrrected (ug/L)
Chlorophyll A, Trichromatic, Unconnected (ug/L)
Chlorophylls . (ug/L)
Chlorophyll C (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L) •
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level III ecoregions:
49, 50, 58, 62. 82
11
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters. Contract # 68-C-99-226, TO# 04 August 8.2000
5.1.5 Aggregate Nutrient Ecoregion 9
Data sources:
Auburn University
Legacy STORET
EPA Region 4
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Pheophytin (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate. (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kj'eldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level in ecoregions:
29,33,35,37,40,45,64,65,71,72,74
5.1.6 Aggregate Nutrient Ecoregion 11
Data sources:
Auburn University
Legacy STORET
NYSDEC
EPA Region 3
EPA Region 4
Parameters:
Chlorophyll A. Fluorometric, Corrected (ug/L)
Chlorophyll A. Pheophytin (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
12
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8, 2000 •
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level HI ecoregions:
36,38,39,66,67,68,69,70
5.1.7 Aggregate Nutrient Ecoregion 12
Data sources:
Legacy STORET
Parameters:
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
.Nitrogen, Total Kjeldahl (TKN) (mg/L) ' .
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level in ecoregions:
75
5.1.8 Aggregate Nutrient Ecoregion 13
Data sources:
Legacy STORET
13
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8. 2000
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
SECCHI (m)
Level in ecoregions:
76
5.2 Rivers and Streams
5.2.1 Aggregate Nutrient Ecoregion 2
Data sources:
Legacy STORET
NASQAN
NAWQA
EPA Region 10
Parameters: • . '
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Phosphorus. Orthophosphate, Total as P (ug/L)
Phosphorus, Total (TP) Reactive (ug/L)
Nitrogen, Total (TN) " (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
14
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Turbidity (FTU)
Turbidity (JCU)
Turbidity (NTU)
Level IB ecoresions:
1, 2,4, 5, 8, 9, 11, 15, 16, 17, 19,21, 23,41, 77, 78
5.2.2 Aggregate Nutrient Ecoregion 3
Data sources:
Legacy STORET
NASQAN "
NAWQA
EPA Region 10
Parameters:
»
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) . (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (JCU)
Turbidity (NTU) .
Level IE ecoregions:
6, 10, 12,13. 14. 18.20,22, 24, 79, 80, 81
15-
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15 Numcnt Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226. TO* 04 August 8, 2000
5.2.3 Aggregate Nutrient Ecoregion 6
Data sources:
Legacy STORE!
NASQAN
NAWQA
EPA Region 5
EPA Region 7
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
• Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Organic, Phosphorus (ug/L)
Phosphorus, Total (TP) (ug/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Turbidity . (FTU)
Turbidity (JCU)
Turbidity " (MTU)
Level III ecoregions:
46, 47, 48. 54, 55, 57
5.2.4 Aggregate Nutrient Ecoregion 7
Data sources:
LCMPD
Legacy STORET
NASQAN
NAWQA
NYCDEP
16
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters. Contract # 68-C-99-226. TO# 04 August 8. 2000 •
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Organic, Phosphorus (ug/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (JCU)
Turbidity (NTU)
Level IH ecoregions:
51,52,53,56,60,61,83
5.2.5 Aggregate Nutrient Ecoregion 9
Data sources:
Auburn University
Legacy STORET
NASQAN
NAWQA
EPA Region 3
EPA Region 5
EPA Region 7 .
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
17
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15 Nutnent Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226. TO# 04 August 8. 2000
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll B, Phytoplankton, Spectrophotometric (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Organic, Phosphorus (ug/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (JCTJ)
Turbidity (NTU)
Level III ecoregions:
29, 33,35,37, 40, 45, 64, 65, 71, 72, 74
5.2.6 Aggregate Nutrient Ecoregion 11
Data sources:
Auburn University
Legacy STORET
NASQAN
NAWQA •
EPA Region 3 • ,
EPA Region 5
EPA Region 7
Parameters:
Chlorophyll A, Fluorometric, Corrected . (ug/L)
Chlorophyll A, Phytoplankton, chromotographic- fluorometric (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected . (ug/L)
Chlorophyll B, Phytoplankton, chromotographic- fluorometric (ug/L)
Phosphorous, Dissolved Inorganic (DEP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Organic, Phosphorus (ug/L)
18
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15 Nutrient Ecorcgion/Waterbody Type Summary Chapters. Contract # 68-C-99-226, TO# 04 August 8, 2000
Phosphorus, Orthophosphate, Total as P (ug/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Turbidity . (FTU)
Turbidity (JCU)
Turbidity (NTU)
Level HI ecoregions:
36, 38, 39, 66, 67,68,69, 70
5.2.7 Aggregate Nutrient Ecoregion 12
Data sources:
Legacy STORET
NASQAN
NAWQA
Parameters:
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Chlorophyll B, Phytoplankton, Spectrophotometric (ug/L)
Phosphorous. Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L) '
Nitrite and Nitrate, (NO2-f-NO3) (mg/L)
Nitrogen, Total (TN) (mg/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity (NTU)
Level HI ecoregions:
75
19
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226. TO# 04 August 8, 2000 •
5.2.8 Aggregate Nutrient Ecoregion 14
Data sources:
Legacy STORET
NASQAN
NAWQA
NYCDEP
EPA Region 1
EPA Region 3
Parameters:
Chlorophyll A, Fluorometric, Corrected (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric Acid (ug/L)
Chlorophyll A, Phytoplankton, Spectrophotometric, Uncorrected (ug/L)
Chlorophyll A, Trichromatic, Uncorrected (ug/L)
Phosphorous, Dissolved Inorganic (DIP) (ug/L)
Dissolved Oxygen (DO) (mg/L)
Nitrite and Nitrate, (NO2+NO3) (mg/L)
Phosphorus, Orthophosphate, Total as P (ug/L)
Nitrogen, Total Kjeldahl (TKN) (mg/L)
Nitrogen, Total (TN) (mg/L)
Phosphorus, Total (TP) (ug/L)
Turbidity (FTU)
Turbidity . (JCU)
Turbidity (NTU)
•
Level HI ecoregions:
59,63,84
20
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15 Nutnent Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8, 2000
APPENDIX A
Process Used to QA/QA the Legacy STORET Nutrient Data Set
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15 Nutnent Ecoregion/Waterbody Type Summary Chapters. Contract # 68-C-99-226, TO# 04 August 8,2000
I. STORET water quality parameters and Station and Sample data items were retrieved
from USEPA's mainframe computer. Table 1 lists all retrieved parameters and data
items.
TABLE 1: PARAMETERS AND DATA ITEMS RETRIEVED FROM STORET
Parameters Retrieved
(STORET Parameter Code)
TN - mg/1 (600)
TKN - mg/1 (625)
Total Ammonia (NH3+NH4) - mg/1 (6 1 0)
Total NO2+NO3 - mg/1 (630)
Total Nitrite -mg/I (6 1 5)
Total Nitrate - mg/1 (620)
Organic N - mg/L (605)
TP - mg/1 (665)
Chlor a - ug/'L (spectrophotometric method.
32211)
Chlor a - ug/L (fluorometric method corrected.
32209)
Chlor a - ug/L (trichromatic method corrected,
32210)
Sccchi Transp. - inches (77)
Secchi Transp. - meters (78)
+Turbidity JCUs (70)
^•Turbidity FTUs (76)
i-Turbidiry NTUs field (82078)
-Turbidity NTUs lab (82079)
-DO - mg/L (300)
+ Water Temperature (decrees C, 10/degrees F,
11)
Station Data Items Included
(STORET Item Name)
Station Type (TYPE)
'Agency Code (AGENCY)
Station No. (STATION)
Latitude - std. decimal degrees
(LATSTD)
Longitude - std. decimal degrees
(LONGSTD)
Station Location (LOCNAME)
County Name (CONAME)
State Name fSTNAME)
Ecoregion Name - Level III
(ECONAME)
Ecoregion Code -Level III
(ECOREG)
Station Elevation (ELEV)
Hydrologic Unit Code
(CATUNIT)
RF1 Segment and Mile
(RCHMIL)
RF1 ON/OFF tag (ONOFF)
Sample Data items
Included
(STORET Item Name)
Sample Date (DATE)
Sample Time (TIME)
Sample Depth (DEPTH)
Composite Sample Code
(SAMPMETH)
- If data record available at a station included data only for this or other such marked parameters, data record was
deleted from data set.
The following set of retrieval rules were applied to the retrieval process:
• Data were retrieved for waterbodies specified only as 'lake', 'stream', 'reservoir',
or 'estuary' under "Station Type" parameter. Any stations specified as 'well,'
'spring,' or 'outfall' were eliminated from the retrieved data set.
• Data were retrieved for station types described as 'ambient' (e.g., no pipe or facility
discharge data) under the "Station Type" parameter.
• Data were retrieved that were designated as 'water' samples only. This includes
"bottom' and 'vertically integrated' water samples.
A-l
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15 Nutrient Ecorcgion/Waierbody Type Summary Chapters, Contract * 68-C-99-226, TO# 04
August 8, 2000"
• Data were retrieved that were designated as either 'grab' samples and 'composite'
samples (mean result only).
• No limits were specified for sample depths.
• Data were retrieved for all fifty states, Puerto Rico, and the District of Columbia.
• The time period specified for data retrieval was January 1990 to September 1998.
• No data marked as "Retired Data" (i.e., data from a generally unknown source) were
retrieved.
• Data marked as "National Urban Runoff data" (i.e., data associated with sampling
conducted after storm events to assess nonpoint source pollutants) were included in
the retrieval. Such data are part of STORET's 'Archived' data.
• Intensive survey data (i.e., data collected as part of specific studies) were retrieved.
Any values falling below the 1st percentile and any values falling above the 99th
percentile were transformed into 'missing' values (i.e., values were effectively removed
from the data set, but were not permanently eliminated).
Based on the STORET 'Remark Code' associated with each retrieved data point, the
following rules were applied (Table 2):
TABLE 2: STORET REMARK CODE RULES
»
STORET Remark Code
blank - Data not remarked.
A-
B-
C-
D-
E-
F-
G-
Value reported is the mean of two or more determinations.
Results based upon colony counts outside the acceptable ranges.
Calculated. Value stored was not measured directly, but was
calculated from other data available.
Field measurement.
Extra sample taken in compositing_process.
In the case of species. F indicates female sex.
Value reported is the maximum of two or more determinations.
Keep or Delete Data Point
Keep
Keep
Delete
Keep
Keep
Delete
Delete
Delete
A-2
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August 8. 2000
TABLE 2: STORET REMARK CODE RULES
H-
I-
J-
K-
L-
M-
N-
O-
P-
Q-
R-
S-
T-
U-
V-
W-
X-
Y-
Z-
Value based on field kit determination; results may not be accurate.
The value reported is less than the practical quantification limit and
greater than or equal to the method detection limit.
Estimated. Value shown is not a result of analytical measurement.
Off-scale low. Actual value not known, but known to be less than
value shown.
Off-scale high. Actual value not known, but known to be greater
than value shown.
Presence of material verified, but not quantified. Indicates a
positive detection, at a level too low to permit accurate
quantification.
Presumptive evidence of presence of material.
Sample for, but analysis lost. Accompanying value is not
meaningful for analysis.
Too numerous to count.
Sample held beyond normal holding time.
Significant rain in the past 48 hours.
Laboratory test.
Value reported is less than the criteria of detection.
Material was analyzed for, but not detected. Value stored is the
limit of detection for the process in use.
Indicates the analyte was detected in both the sample and associated
method blank.
Value observed is less than the lowest value reportable under
remark "T."
Value is quasi vertically-integrated sample.
Laboratory analysis from unpreserved sample. Data may not be
accurate.
Too many colonies were present to count.
Delete
Keep, but used one-half the
reported value as the new value.
Delete
Keep, but used one-half the reported
value as the new value.
Keep
Keep, but used one half the reported
value as the new value.
Delete
Delete
4
Delete
Delete
Delete
Keep
Keep, but replaced reported value with
0.
Keep, but replaced reported value with ,
0.
Delete
Keep, but replaced reported value with
.0.
No data point with this remark code in
data set.
Delete
Delete
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15 Numem Ecoregion/'Waterbody Type Summary Chapters, Contract tt 68-C-99-226. TOtt 04 August 8. 2000
TABLE 2: STORET REMARK CODE RULES
If a parameter (excluding water temperature) value was less than or equal to zero and no remark code was present,
the value was transformed into a missing value.
Rationale - Parameter concentrations should never be zero without a proper explanation. A method detection limit
should at least be listed.
4. Station records were eliminated from the data set if any of the following descriptors were
present within the "Station Type" parameter:
* MONITR - Source monitoring site, which monitors a known problem or to detect
a specific problem.
* HAZARD - Site of hazardous or toxic wastes or substances.
>• ANPOOL - Anchialine pool, underground pools with subsurface connections to
watertable and ocean.
> DOWN - Downstream (i.e., within a potentially polluted area) from a facility
which has a potential to pollute.
»• IMPDMT - Impoundment. Includes waste pits, treatment lagoons, and settling
and evaporation ponds.
»• STMSWR-Storm water sewer.
> LNDFL - Landfill.
»• CMBMI - Combined municipal and industrial facilities.
»• CMBSRC - Combined source (intake and outfall).
Rationale - these descriptors potentially indicate a station location that at which an
ambient water sample would not be obtained (i.e., such sampling locations are potentially
biased) or the sample location is not located within one of the designated water body types
(i.e, ANPOOL).
5. Station records were eliminated from data set if the station location did not fall within any
established cataloging unit boundaries based on their latitude and longitude.
6. Using nutrient ecoregion GIS coverage provided by USEPA. all station locations with
latitude and longitude coordinates were tagged with a nutrient ecoregion identifier
(nutrient region identifiers are values 1-14) and the associated nutrient ecoregion name.
Because no nutrient ecoregions exist for Alaska, Hawaii, and Puerto Rico, stations located
in these states were tagged with "dummy" nutrient ecoregion numbers (20 = Alaska, 21 =
Hawaii, 22 = Puerto Rico).
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract tt 68-C-99-226. TO# 04 August 8. 2000
7. Using information provided by TV A, 59 station locations that were marked as 'stream'
locations under the "Station Type" parameter were changed to 'reservoir' locations.
8. The nutrient data retrieved from STORET were assessed for the presence of duplicate data
records. The duplicate data identification process consisted of three steps: 1) identification
of records that matched exactly in terms of each variable retrieved; 2) identification of
records that matched exactly in terms of each variable retrieved except for their station
identification numbers; and 3) identification of records that matched exactly in terms of
each variable retrieved except for their collecting agency codes. The data duplication
assessment procedures were conducted using SAS programs.
Prior to initiating the data duplication assessment process, the STORET nutrient data set
contained:
41,210 station records
924,420 sample records
• Identification of exactly matching records
All data records were sorted to identify those records that matched exactly. For two
records to match exactly, all variables retrieved had to be the same,' For example,
they had to have the same water quality parameters, parameter results and associated
remark codes, and have the same station data item and sample data item information.
Exactly matching records were considered to be exact duplicates, and one duplicate
record of each identified matching set were eliminated from the nutrient data set. A
total of 924 sample records identified as duplicates by this process were eliminated
from the data set.
• Identification of matching records with the exception of station identification number
All data records were sorted to identify those records that matched exactly except for
their station identification number (i.e., they had the same water quality parameters,
parameter results and associated remark codes, and the same station and sample data
item information with the exception of station identification number). Although the
station identification numbers were different, the latitude and longitude for the
stations were the same indicating a duplication of station data due to the existence of
two station identification numbers for the same station. For each set of matching
records, one of the station identification numbers was randomly selected and its
associated data were eliminated from the data set. A total of 686 sample records
were eliminated from the data set through this process.
• Identification of matching records with the exception of colleoting aeencv codes
All data records were sorted to identify those records that matched exactly except for
their collecting agency codes (i.e., they had the same water quality parameters,
parameter results and associated remark codes, and the same station and sample data
item information with the exception of agency code). The presence of two matching
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters. Contract # 68-C-99-226, TO# 04 August 8,2000
data records each with a different agency code attached to it suggested that one
agency had utilized data collected by the other agency and had entered the data
into STORET without realizing that it already had been placed in STORET by the
other agency. No matching records with greater than two different agency codes
were identified. For determining which record to delete from the data set, the
following rules were developed:
*• If one of the matching records had a USGS agency code, the USGS record
was retained and the other record was deleted.
>• Higher level agency monitoring program data were retained. For example,
federal program data (indicated by a "1" at the beginning of the STORET
agency code) were retained against state (indicated by a "2") and local
(indicated by values higher than 2) program data.
»• If two matching records had the same level agency code, the record from the
agency with the greater number of overall observations (potentially indicating
the data set as the source data set) was retained.
A total of 2,915 sample records were eliminated through this process.
As a result of the duplicate data identification process, a total of 4,525 sample records and
36 individual station records were removed from the STORET nutrient data set. The
resulting nutrient data set contains the following:
41,174 station records
919,895 sample records
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15 Nutrient EcoregionAVaterbody Type Summary Chapters, Contract # 68-C-99-226, TO# 04 August 8. 2000
APPENDIX B
Process for Adding Aggregate Nutrient Ecoregions and Level in Ecoregions
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15 Nutrient Ecoregion/Waterbody Type Summary Chapters, Contract # 68-C-99-226, TO* 04 August 8. 2000
Steps for assigning Level EH ecoregions and aggregate nutrient ecoregion codes and names to the
Nutrient Criteria Database (performed using ESRI's ARCView v 3.2 and its GeoProcessing
Wizard). This process is performed twice; once for the Level HI ecoregions and once for the
aggregate nutrient ecoregions:
Add the station .dbf data table, with latitude and longitude data, to project by 'Add Event
Theme1
Convert to the shapefile format
Create 'stcojoin1 field, populate the 'stcojoin1 field with the following formula:
'County.LCase+State.LCase'
Add field 'stco_flag' to the station shapefile
Spatially join the station data with the county shapefile (cntysjned.shp)
Select 'stcojoin' (station shapefile) field = 'stco Join2' (county shapefile) field
Calculate "stco_flag = 0 for selected features
Step through all blank stco_flag records, assign the appropriate stco_flags, see list on the
following page
Select all stco_flags = 4 or 7, switch selection
Calculate ctyfips (station) to cntyfips (county)
Stop editing and save edits, remove all joins
Add in 2 new fields 'x-coordl1 and 'y-coordl' into station table
Select all stco_flags =1,2, and 6
Link county coverage with station coverage
Populate 'x-coordl' and 'y-coord I' with 'x-coord* and 'y-coord' from county coverage
Select all stco_flags =1,2, and 6, export to new .dbf file
Add new .dbf file as event theme
Convert to shapefile format
Add the following fields to both tables (original station and station 126 shapefiles):
'ecojamer1, Iname_omer', Idis_aggr1, 'code_aggrl, lname_aggrl
Spatially join station!26 and eco-omer coverage
Populate the 'eco^mer1 field with the 'eco' value
Repeat the previous step using the nearest method (line coverage) to determine ecoregion
assignment for the line coverage, if some records are blank
Spatially join the ecoregion line coverage to station coverage, link the
LPoly# (from the spatially joined table) to Poly# (of the ecoregion polygon
coverage)
Populate the Eco fields with the appropriate information.
Follow the same steps to the Rpolytf
Remove all table joins
Link the useco-om table with stationl26 table and populate 'name-omer1 field
Spatially join station aggr coverage and populate the rest of the fields. Follow the same
procedures as outlined above
Remove all joins
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15 Nutrient EcoregioivWaierbody Type Summary Chapters. Contract» 68-C-99-226, TOO 04 August 8,2000
Make sure the new Eco field added into the station 126 shapefile are different than the
ones in the original station shapefile
Join station!26 and station coverage by station-id
Populate all the Eco fields in the original station coverage
Remove all joins
Save table
Make sure that all ctyfips records are populated; the county shapefile may have to be
joined to populate the records, if the stco_flag = 4
Create 2 new fields, "NewCounty1 and 'NewState1
Populate these new fields with a spatial join to the county coverage
Select by feature (ecoregion shapefile) all of the records in the station shapefile
Switch selection (to get records outside of the ecoregion shapefile)
If any of the selected records have stco_flag = 0 (they are outside the ecoregion
shapefile boundary), calculate them to stco_flag = 3
stco_flags (state/county flags in order of importance)
0 The state and county values from the data set matched the state and county values
from the spatial join.
(Ecoregions were assigned based on the latitude/longitude coordinates.)
1 The state and county values from the data set did not match the state and county
values from the spatial join, but the point was inside the county coverage
boundary.
(Ecoregions were assigned based on the county centroid.)
2 The state and county values from the data set did not match the state and county
values from the spatial join because the point was outside the county coverage
boundary; therefore, there was nothing to compare to the point (i.e., the point
falls in the ocean/Canada/Mexico). This occurred for some coastal samples.
(Ecoregions were assigned based on the county centroid.) '
3 The state and county values from the data set matched the state and county from
the spatial join, but the point was outside the ecoregion boundary.
(Ecoregions were assigned to the closest ecoregion to the point.)
(No ecoregions were assigned to AK, HI, PR, BC, and GU.)
4 Latitude/longitude coordinates were provided, but there was no "county
information.
(Ecoregions were assigned based on the latitude/longitude coordinates.)
5 The state and county values from the data set did not match the state and county
values from the spatial join due to spelling or naming convention errors.
The matches were performed manually.
(Ecoregions were assigned based on the latitude/longitude coordinates.)
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15 Nutneiu'Ecoregion/Waierbody Type Summary Chapters. Contract # 68-C-99-226, TO# 04 August 8.2000
6 No latitude/longitude coordinates were provided, only state and county
information was available.
(Ecoregions were assigned based on the county centroid.)
7 No latitude/longitude coordinates were provided, only state information was
available; therefore, no matches were possible.
(Ecoregions were not assigned. Data is not included in the analysis.)
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