United States Office of August 14, 1991
Environmental Protection Wetlands, Oceans,
Agency and Watersheds
vvEPA Side-By-Side
Comparison Of The
1989 Manual And
Proposed Revised
Manual
EJBD
ARCHIVE
EPA
840-
K-
91-
001
Printed on Recycled Paper
-------
BASING WETLANDS DETERMINATIONS ON 3 PARAMETERS - HYDROLOGY,
VEGETATION, AND SOILS
1989 MANUAL:
Evidence of all 3 parameters are required, BUT could assume hydrology from
vegetation or soils IF area was disturbed.
Could assume vegetation from soils and hydrology.
Could assume soils from certain vegetation.
PROPOSED REVISED MANUAL:
Independent indicators of all 3 parameters are required UNLESS the area is a
disturbed wetland or the area is a specifically described exception (e.g., playa
lake, prairie pothole, vernal pool, pocosin, and other special wetlands that fail
the hydrophytic vegetation criterion). Exceptions are widely recognized valuable
wetland types that may fail to meet one or more of the 3 criteria.
Requests public comment on the listed exceptions as well as potential additions
to the list, and on recommendations for identifying appropriate indicators for
each wetland type listed as an exception.
Requests public comment on three alternatives to identifying and delineating
seasonally harder to identify wetland types that are NOT exceptions to the
criteria, but may not demonstrate indicators of one or more of the 3 criteria
during certain (e.g., dry) times of the year.
Repository Material
Permanent Collection
US EPA
Headquarters and Chemical Libraries
EPA West Bldg Room 3340
Mailcode 3404T
1301 Constitution Ave NW
Washington DC 20004
202-566-0656
-------
DURATION OF INUNDATION AND/OR SATURATION IN THE WETLAND
HYDROLOGY CRITERION
1989 MANUAL:
Requires inundation or saturation for one week or more during the growing
season.
PROPOSED REVISED MANUAL:
Requires inundation for 15 or more consecutive days, or saturation to the surface
for 21 or more consecutive days during the growing season.
-------
DEPTH AT WHICH SOIL SATURATION IS REQUIRED IN THE WETLAND
HYDROLOGY CRITERION
1989 MANUAL:
Requires saturation to the surface at some point in time during the growing
season.
Saturation to the surface would normally occur when, for one week or more, the
water table is within:
• 6 inches of the soil surface in somewhat poorly drained mineral soils,
• 12 inches of the soil surface in poorly drained or very poorly drained
mineral soils, or
• 18 inches of the soil surface in poorly drained or very poorly drained
mineral soils with low permeability (less than 6 inches per hour).
The above-listed depths to the water table were intended to correspond to
saturation to the surface caused by capillary action above the water table.
PROPOSED REVISED MANUAL:
Requires inundation and/or saturation at the surface.
1989 Manual depths to water table as indicators of surface saturation are
deleted; replaced by a test for water that can be squeezed or shaken from the
surface soil to ensure that capillary action is saturating the soil at the surface.
-------
TECHNICAL VALIDITY OF ACCEPTABUE INDICATORS OF WETLAND
HYDROLOGY
1989 MANUAL:
The list of wetland hydrology indicators included both strong and weak
indicators, each of which alone could be used to meet the wetland hydrology
criterion.
Hydric soil characteristics alone also could be used to meet the hydrology
criterion.
PROPOSED REVISED MANUAL:
Eliminates hydric soil characteristics as hydrology indicators.
Separates list of hydrology indicators into primary and secondary indicators.
Primary indicators are more reliable and can be used alone to meet hydrology
criterion.
Secondary indicators are weaker and can only be used with corroborative
information. This corroborative information must be of sufficient quality and
extent that when taken together with secondary indicators clearly supports the
presence of wetland hydrology for the necessary time, duration, and frequency.
Requests public comment on the validity of secondary indicators.
Removes water-stained leaves, trunks, or stems and requests public comment on
including this as indicators of hydrology, their reliability as indicators of hydrology
and whether they should be primary or secondary indicators.
Solicits comments on the data requirements for hydrologic records (e.g., cutoff
for "normal rainfall" years) to document that the wetland hydrology criterion has
been met.
-------
DEFINITION OF GROWING SEASON
1989 MANUAL:
Used growing season zones mapped in broad bands across the country according
to soil temperature regimes.
PROPOSED REVISED MANUAL:
Growing season is based on local weather data, and will be from 3 weeks before
the last killing frost in the Spring to 3 weeks after the first killing frost in the
Fall, except for areas that experience freezing temperatures throughout the year,
where appropriate local growing seasons will be applied. The local weather data
will be available on a local level, e.g. the county level.
Solicits comment on this definition.
-------
PUBLIC INPUT TO THE REVISION PROCESS
1989 MANUAL:
As an interpretation of the existing regulatory definition of wetlands, the Manual
was not required to go through notice and comment rulemaking. There was no
opportunity for public input on the Manual prior to its issuance or
implementation.
PROPOSED REVISED MANUAL:
The Agencies held 4 public meetings last Summer and accepted written
comments on the 1989 Manual until September 28, 1990. These comments were
considered in developing the proposed revisions.
The Manual will be formally proposed in the Federal Register. The position
that this Manual is a technical guidance document which is not required by law
to go through Administrative Procedure Act (APA) legislative rulemaking
procedures has been upheld with respect to the 1989 wetlands delineation
manual in Hobbs v. United States. 32 Env't Rep. Cas. (BNA) 2091 (E.D. Va.
1990), appeal pending. No. 90-1861 (4th Cir.). Nonetheless, the agencies believe
that it would be appropriate and in the public interest to include parts of the
final manual in the Code of Federal Regulations. When the agencies determine
what portions of the manual that may be promulgated as a legislative rule, they
will provide notice of specific proposed regulatory language in the FEDERAL
REGISTER at least 30 days prior to the end of the public comment period.
The regulatory language will be subject to the Administrative Procedure Act
rulemaking process.
-------
HYDROPHYTIC VEGETATION CRITERION
1989 MANUAL:
Requires under normal circumstances: 1) more than 50% of the composition of
the dominant species from all strata are obligate wetland, facultative wetland,
and/or facultative wetland species; OR 2) the prevalence index approach (that is,
under normal circumstances, a frequency analysis of all species within the
community yields a prevalence index value of less than 3.0 (where OBL = 1.0,
FACW = 2.0, FAC = 3.0, FACU = 4.0, and UPL = 5.0).
PROPOSED REVISED MANUAL:
Proposes the prevalence index approach -- that is, an area meets this criterion if,
under normal circumstances, a frequency analysis of all species within the
community yields a prevalence index value of less than 3.0 (where OBL = 1.0,
FACW = 2.0, FAC = 3.0, FACU = 4.0, and UPL = 5.0).
Solicits comments on including the Facultative Neutral test as part of the
hydrophytic vegetation criterion in addition to the proposed prevalence index
approach. Under this approach the criterion would be met if after discounting
all dominant facultative (FAC) plants, the number of dominant obligate wetland
(OBL) and facultative wetland (FACW) species exceeds the number of dominant
facultative upland (FACU) and obligate upland (UPL) species. (Note: a number
of options are presented describing circumstances under which,the prevalence
index procedure would be used.)
Solicits comments on variants of the FAC neutral test.
-------
STATUS OF DELINEATIONS BASED ON THE 1989 FEDERAL MANUAL
1989 MANUAL:
Required the use of 1989 Manual for delineation and such delineations were
final.
PROPOSED REVISED MANUAL:
Any landowner whose land has been delineated a wetland after the revised
Manual is proposed but before the proposed revised Manual becomes final may
request a new delineation following publication of the final revised Manual.
However, final actions, such as permit issuances or completed enforcement
actions, already taken on wetlands delineated under the 1989 manual will not
generally be reopened.
A landowner whose property has been identified as a wetland during a seasonal
dry period or drought can request a re-evaluation in the field during the wet
season of the year.
The agencies are soliciting comment on the likelihood of sites being delineated
during the dry season as wetland that, if the delineation had occurred during the
wet season, would not have met the hydrology criterion. Should requests for re-
evaluations be limited to certain cases or should all requests be granted?
-------
DEFINITION OF A DISTURBED WETLAND AREA AND ITS DELINEATION
PROCEDURES
1989 MANUAL:
Disturbed wetland areas include situations where field indicators of one or more
of the three wetland identification criteria are obliterated or not present due to
recent change.
For disturbed areas where vegetation is removed and no other alterations have
been done, the presence of hydric soils and evidence of wetland hydrology will
be used to identify wetlands. If such evidence is found, conditions are assumed
to be sufficient to support hydrophytic vegetation.
PROPOSED REVISED MANUAL:
Disturbed wetland areas are wetlands that met the mandatory criteria prior to
disturbance and have had vegetation, soils, and/or hydrology altered such that the
required evidence of the relevant indicators for the affected criteria has been
removed. If a disturbed area is identified as a wetland, field personnel shall
uocument the reasons for determining that the site would have been a wetland
but for the disturbance.
For disturbed area where the vegetation is removed and no other alterations
have been done, evidence of the elimination of the hydrophytic vegetation
together with the presence of hydric soils and evidence of wetland hydrology
must be used to identify wetlands.
-------
ALTERNATIVE APPROACH TO DELINEATION ON A SITE-SPECIFIC BASIS
1989 MANUAL:
Sites are delineated individually.
PROPOSED REVISED MANUAL:
Sites are delineated individually.
Solicits comments on alternative approaches that would allow identification of
categories that can be identified and delineated rapidly and without the need for
extensive documentation.
10
------- |