The Iowa Department of Natural Resources TMDL and Water Quality Assessment
Section compiles this impaired water list, or 303(d) listing. The 303(d) listing
is composed of those lakes, wetlands, streams, rivers, and portions of rivers
that do not meet all state water quality standards. These are considered
"impaired waterbodies" and states are required to calculate
total maximum daily loads (TMDLs) for pollutants causing impairments.
Current 303(d) Listing:1998 Impaired Waters List
Iowa DNR submitted its final 2006 Integrated Report, including Iowa's 2006 list of impaired waters to U.S. EPA for approval on October 23, 2007.
Public comments were sought on Iowa’s draft 2006 list from May 3 through June 29, 2007.
Seven individuals or organizations, including U.S. EPA Region 7, responded with comments.
As a result of these comments, one waterbody was removed and nine waterbodies were added to Iowa’s final list.
Thus, Iowa's final 2006 Section 303(d) list, as submitted to U.S. EPA on October 23, 2007 for review and approval,
contains 282 waterbodies. IDNR expects an approval/disapproval decision from U.S. EPA by early 2008.
All states submit their Integrated Report and list of impaired waters every two years as required by Sections
305(b) and 303(d) of the Clean Water Act. Iowa’s 2006 Integrated Report was prepared according to U.S. EPA guidelines that combine
(integrate) requirements of Sections 305(b), 303(d), and 314 of the federal
Clean Water Act [see http://www.epa.gov/owow/tmdl/2006IRG/].
These guidelines suggest that states place all their waters into one of five
categories of their Integrated Reports:
• Category 1: All designated uses are met.
• Category 2: Some of the uses are met but insufficient information exists to determine whether the remaining
uses are met.
• Category 3: Insufficient information exists to determine whether any uses are met.
• Category 4: The waterbody is impaired but a TMDL is not required.
• Category 5: The waterbody is impaired and a total maximum daily load (TMDL)
is needed. Category 5 is the state’s Section 303(d)
list.
(*designated uses, as described in the Iowa Water Quality Standards, include Class A (primary contact recreation) uses,
Class B (aquatic life) uses, and Class C (drinking water) uses. Any Iowa waterbody can be designated for one or a combination of these three types of beneficial use.)
Iowa’s 2006 Section 303(d) list (Category 5 of the Integrated Report) is the third
such list to be developed under Iowa’s
Credible Data Law.
This law, passed by the Iowa Legislature in 2000, requires that listing decisions be based on scientifically valid chemical,
physical, or biological data collected under a scientifically accepted sampling and analysis plan, including quality
control and quality assurance procedures. The Department believes this “credible data” law has been implemented in
conjunction with the federal listing requirements such that all readily available and existing water quality related
data and information have been used for list development.
As provided for in Iowa's credible data law, the Department is to maintain a separate list of waters that require
further investigative monitoring. As specified in the credible data law, this list is not part of the Section 303(d)
process in Iowa and includes waterbodies where limited information suggests, but does not conclusively (credibly)
demonstrate, that a water quality impairment exists. If the results of further investigative monitoring demonstrate, with data
of sufficient quality and quantity, that a water quality impairment exists, the affected waterbody can be added to
Iowa's Section 303(d) list. Iowa's 2006 list of waters in need of further investigation (WINOFI) contains 139
waterbodies including 93 river/stream segments, 9 lakes, and 37 wetlands. Iowa’s 2004 list of waters in need of
further investigation contained 101 waterbodies. While 78 of these waterbodies remain on Iowa’s 2006 “further
investigation” list, the remainder of the 101 waterbodies were moved to other categories of the 2006 Integrated
Report as follows:
• eight waterbodies were assessed with more recent data as “fully supporting” and were placed in Categories 1 or 2;
• three waterbodies with approved TMDLs were moved to Category 4a;
• five waterbodies were assessed with more recent data as “impaired” and in need of a TMDL and were placed in Category 5 (=Section 303(d) list);
• six waterbodies were assessed as “fully supporting” for the 2006 reporting/listing cycle and moved to
Categories 1 or 2 due to changes or updates in IDNR’s assessment methodology (for example, (1) the EPA-recommended
elimination of the “fully supported/threatened” assessment category and (2) the update of IDNR’s biological
impairment criteria);
• one waterbody was removed due to an error in the 2004 assessment.
The following materials comprise Iowa's final 2006 Integrated Report that
were submitted to U.S. EPA on October 23, 2007 for their approval:
Request for public comments:
Iowa DNR has prepared a draft 2006 list of impaired waters as required by Section 303(d) of the federal Clean
Water Act. Iowa DNR is now seeking public comments on this draft list. Public comments will be solicited
from May 1 through June 29, 2007. Following the end of the public comment period, the draft list will be
modified based on the comments received, and the list will be forwarded to U.S. EPA for their review and
approval or disapproval.
Please mail comments to:
Iowa Department of Natural Resources
Attention: John Olson
Watershed Monitoring & Assessment Section
Wallace State Office Building
502 East 9th Street
Des Moines, IA 50319
Comments can also be e-mailed to the following address:
john.olson@dnr.state.ia.us.
Iowa’s draft 2006 Section 303(d) list of impaired waters was prepared according to U.S. EPA guidelines for
“integrated reporting” that combines requirements of Sections 305(b), 303(d), and 314 of the federal Clean
Water Act (see http://www.epa.gov/owow/tmdl/2006IRG/. These guidelines suggest that states place all their
waters into one of five categories of their Integrated Report:
• Category 1: All designated uses are met.
• Category 2: Some of the uses are met but insufficient information exists to determine whether the remaining
uses are met.
• Category 3: Insufficient information exists to determine whether any uses are met.
• Category 4: The waterbody is impaired but a TMDL is not required.
• Category 5: The waterbody is impaired and a total maximum daily load (TMDL) is needed (i.e., the state’s Section 303(d) list).
Iowa’s 2006 Section 303(d) list is the third to be developed under Iowa’s
Credible Data Law. This law requires
that listing decisions be based on scientifically valid chemical, physical, or biological data collected under a
scientifically accepted sampling and analysis plan, including quality control and quality assurance
procedures. The Department believes this “credible data” law has been implemented in conjunction with the
federal listing requirements such that all readily available and existing water quality related data and
information have been used for list development.
Iowa's draft 2006 Section 303(d) list
(Category 5 of the Integrated Report) contains 274 waterbodies with a
total of 356 impairments Of these impairments, 158 impairments are new to the impaired waters list and are
based primarily on new monitoring data.
As provided for in Iowa's credible data law, the Department is to maintain
a separate list of waters that require further investigative monitoring. As specified in the credible data law, this list is not part of the Section 303(d)
process in Iowa and includes waterbodies where limited information suggests, but does not conclusively
(credibly) demonstrate, a water quality impairment. If the results of further investigative monitoring
demonstrate, with data of sufficient quality and quantity, that a water quality impairment exists, the affected
waterbody can be added to Iowa's Section 303(d) list. Iowa's draft 2006 list of waters in need of further
investigation contains 175 waterbodies including 128 river/stream segments, 10 lakes, and 37 wetlands.
Iowa’s 2004 list of waters in need of further investigation contained 101 waterbodies. While 76 of these
waterbodies remain on Iowa’s draft 2006 “further investigation” list, 24 waterbodies on the 2004 WINOFI list
were moved to other categories of the draft 2006 Integrated Report as follows:
• 13 waters were assessed as “fully supporting” and were placed in IR Categories 1 or 2;
• 1 waterbody is now considered “not assessed” because more than six years have elapsed since
occurrence of the fish kill that led to impairment
• 3 waterbodies were assessed as “impaired” but the impairment does not require preparation and approval
of a TMDL; these waterbodies were placed in Category 4;
• 7 waterbodies were assessed as “impaired” and in need of a TMDL and were placed in Category 5 (=Section 303(d) list).
The following materials are presented for review:
Iowa’s 2004 Section 303(d) list of impaired waters was prepared according to
U.S. EPA guidelines for “integrated reporting” that combines requirements of
Sections 305(b), 303(d), and 314 of the federal Clean Water Act. These
guidelines suggest that states place all their waters into one of five
categories of their 2004 Integrated Report:
• Category 1: All designated uses are met.
• Category 2: Some of the uses are met but insufficient information exists to
determine whether the remaining uses are met.
• Category 3: Insufficient information exists to determine whether any uses are
met.
• Category 4: The waterbody is impaired but a TMDL is not required.
• Category 5: The waterbody is impaired and a total maximum daily load (TMDL) is
needed (i.e., the state’s Section 303(d) list).
Iowa’s 2004 Section 303(d) list is the second to be developed under Iowa’s
Credible Data Law. This law requires that listing decisions be based on
scientifically valid chemical, physical, or biological data collected under a
scientifically accepted sampling and analysis plan, including quality control
and quality assurance procedures. The Department believes this
“credible data”
law has been implemented in conjunction with the federal listing requirements
such that all readily available and existing water quality related data and
information have been used for list development.
Public comments were sought on Iowa’s draft 2004 list from February 21 through
April 15, 2005. The public comment period was initially set to end on April 1st
but was extended to allow the public more time to review the list. Comments were
received from six individuals and organizations.
Iowa's 2004 Section 303(d) list with 209 waterbodies was submitted to the
Environmental Protection Agency (EPA) on May 26, 2005 for review and approval.
Based on their review, EPA partially approved and partially disapproved Iowa's
submitted 303(d) list in November 2005. As part of their decision, EPA proposed
to add back 20 waterbodies and associated pollutants of concern to Iowa's 2004
list of impaired waters that Iowa had not included on their May 2005 list. EPA
took public comments on their decision from November 18 to December 19, 2005.
Based on public comments received and on EPA’s further review, Iowa received its
final/approved 2004 Section 303(d) list of impaired waters from EPA on May 23,
2006. Of the 20 water bodies proposed for listing by EPA, 17 were included on
Iowa's final 2004 list. Iowa's final-approved 2004 Section 303(d) list contained
225 waterbodies. EPA also approved the removal of 43 waterbodies from Iowa’s
2002 Section 303(d) list for the following reasons: TMDLs for 12 waterbodies
were developed by IDNR and approved by EPA; new data for 13 waterbodies
supported removal from the Section 303(d) list, flaws in the original assessment
resulted in removal of 12 waterbodies, and changes in the IDNR waterbody
identification numbers for six waterbodies required their removal from the 2004
Section 303(d) list (these six waterbodies, however, remain (with new
identification numbers) on Iowa’s 2004 Section 303(d) list (Category 5)).
As provided for in Iowa's credible data law, the Department is to maintain a
separate list of waters that require further investigative monitoring. As
specified in the credible data law, this list is not part of the Section 303(d)
process in Iowa and includes waterbodies where limited information suggests, but
does not conclusively (credibly) demonstrate, a water quality impairment. If the
results of further investigative monitoring demonstrate, with data of sufficient
quality and quantity, that a water quality impairment exists, the affected
waterbody can be added to Iowa's Section 303(d) list. Iowa's 2004 list of waters
in need of further investigation contains 101 waterbodies including 53
river/stream segments, 12 lakes, and 36 wetlands. Iowa’s 2002 list of waters in
need of further investigation contained 170 waterbodies. While 65 of these
waterbodies remain on Iowa’s 2004 “further investigation” list, the remainder of
the 170 waterbodies were moved to other categories of the 2004 Integrated Report
as follows:
• 18 waters were assessed as “fully supporting” and were placed in Categories 1
or 2;
• 37 waterbodies were assessed as “impaired” but the impairment does not require
preparation of a TMDL; these waterbodies were placed in Category 4;
• 50 waterbodies were assessed as “impaired” and in need of a TMDL and were
placed in Category 5 (=Section 303(d) list).
The removal of these 105 waterbodies from Iowa’s “further investigation” list
resulted either from the existence of new water quality data or from a change in
IDNR’s assessment methodology.
The State of Iowa has identified 188 waterbodies for the 2002 Impaired Waters
List.
Iowa’s 2002 Section 303(d) list is the first to be developed under a
new state law passed by the Iowa Legislature in 2000. This law requires that
listing decisions be based on scientifically valid chemical, physical, or
biological data collected under a scientifically accepted sampling and analysis
plan, including quality control and quality assurance procedures. The Department
believes this “credible data” law can be
implemented in conjunction with the federal listing requirements to use all
readily available and existing water quality related data and information.
Public comments were sought on the list from August 19th through November 1,
2002. The public comment period was initially set to end on September 19th, but
was extended to allow the public more time to review the list. Comments were
received from approximately 30 individuals and organizations.
Iowa's 2002 Section 303(d) list was submitted to the
Environmental Protection Agency on December 18th, 2002 for review and
approval. On July 11, 2003, EPA partially approved and partially disapproved
Iowa's submitted 303(d) list. EPA proposed to add back 20 water bodies and
associated pollutants of concern to Iowa's 2002 list of impaired waters that
Iowa had not included on the list. Of the 20 water bodies proposed for listing
by EPA, 18 are included on Iowa's final 2002 list. EPA also approved Iowa's
listing of 136 water bodies and delisting of 71 water bodies.
Iowa's Final 2002 Section 303(d) list contains 205 waterbodies and 286
impairments.
As provided for in Iowa's credible data law,
the Department is to maintain a separate list of waters that require further
investigative monitoring. As specified in the credible data law, this list is
not part of the Section 303(d) process in Iowa and includes waterbodies where
limited information suggests, but does not conclusively (credibly) demonstrate,
a water quality impairment. If the results of further investigative monitoring
demonstrate, with data of sufficient quality and quantity, that a water quality
impairment exists, the affected waterbody can be added to Iowa's Section 303(d)
list. Iowa's 2002 list of waters in need of further investigation contains 171
waterbodies including 108 river/stream segments, 23 lakes, and 40 wetlands.
The Iowa Department of Natural Resources has identified 157 waters in the
state for which existing required pollution controls are not stringent enough to
implement state water quality standards. The Federal Clean Water Act Section
303(d) requires that each state establish a list of these waters, and the 1998
list is available. The state is required to establish total maximum daily loads
(TMDLs) for waters on the list according to priority ranking. This list was
originally published as a draft, subjected to public comment and revised prior
to adoption.