40464 Federal Register / Vol. 56, No. 157 / Wednesday. August 14, 1991 / Proposed Rules 



determination. For more accurate 

 results, one must conduct an onsite 

 inspection. 



Appendix 2. Routine Onsite 

 Determination Method 



For most cases, weUand 

 determinadons can be made in the field 

 without rigorous sampling of vegetation 

 and soils. Two approaches for routine 

 determinations are presented: (1) Hydric 

 soil assessment procedure, and (2) plant 

 community assessment procedure. In the 

 former approach, areas that meet or may 

 meet the hydric soil estimated to 

 determine if hydrophytic vegetation is 

 obvious. If so, the area is searched for 

 indicators of weUand hydrology. If 

 positive indicators of hydric soils, 

 hydrophytic vegetation, and wetland 

 hydrology are present, the area is 

 designated as wetiand. If not, then the 

 site must undergo a more rigorous 

 evaluation foUoviring one of the other 

 onsite determination methods presented 

 in the manual. The second routine 

 approach requires initial identification 

 of representative plant community types 

 in the subject area and then 

 characterization of vegetation, soils, and 

 hydrology for each type. After 

 identifying wetiand and nonwedand 

 communities, the weticuid boundary is 

 delineated. All pertinent observations 

 on the three mandatory wetland criteria 

 should be recorded on an appropriate 

 data sheet; this should be done for all 

 inspections to determine regulatory 

 jurisdiction. 



Hydric Soil Assessment Procedure 



Step 1. Identify the approximate limits 

 of areas that may meet the hydric soil 

 criterion within the area of concern and 

 sketch limits on an aerial photograph. 

 To help identify these limits use sources 

 of information such as Agricultural 

 Stabilization and Conservation slides, 

 soil surveys, NWI maps, and other maps 

 and photographs. 



(Note: This step is more convenient to 

 perform offsite. but may be done onsite.) 



Proceed to Step 2. 



Step 2. Scan the areas that may meet 

 the hydric soil criterion and determine if 

 disturbed conditions exist. Are any 

 significanUy disturbed areas present? If 

 yes, identify their limits for they should 

 be evaluated separately for weUand 

 determination purposes (usually after 

 evaluating undisturbed areas). Refer to 

 the section on disturbed areas, if 

 necessary, to evaluate the altered 

 characteri3tic(s) (vegetation, soils, or 

 hydrology). If appropriate, determine 

 whether wetiand regulatory policy 

 exempts the area from Federal 

 regulatory jurisdiction (e.g., regulatory 



policy on wetlands converted to 

 cropland. See Disturbed Areas 

 discussion; then return to this method 

 and continue evaluating characteristics 

 not altered. (Note: Prior experience with 

 disturbed sites may allow one to easily 

 evaluate an altered characteristic, such 

 as when vegetation is not present in a 

 farmed wetland due to cidtivation.) 

 Keep in mind that if at any time during 

 this determination, one or more of these 

 three characteristics are found to have 

 been significantly altered, the disturbed 

 area determination procediires should 

 be followed. If the area is not 

 significanUy disturbed, proceed to Step 

 3. 



Step 3. Scan the areas that may meet 

 the hydric soil criterion and determine if 

 obvious signs of weUand hydrology or 

 hydric soil are present The wetland 

 hydrology criterion is met for any area 

 or portion thereof where it is obvious or 

 knov«i that the area is frequenUy 

 inundated or saturated at the surface for 

 a sufficient duration during the growing 

 season in most years. Confirm the 

 presence of hydric soil by examining the 

 soil for appropriate properties. If the 

 area has obvious positive indicators of 

 weUand hydrology, the hydrology has 

 not been significanUy disturbed, the soil 

 is organic (Histosols, except Folists) or 

 is mineral classified as Sulfaquents, 

 Hydraquents, or Histic subgroups of 

 Aquic Suborders, and the area has 

 hydrophytic vegetation, then the area is 

 weUand. Hydrophytic vegetation should 

 be obvious in these situations. Areas 

 lacking obvious indicators of weUand 

 hydrology, readily obvious hydric soUs, 

 or hydrophytic vegetation must be 

 further examined, so proceed to Step 4. 



Step 4. Refine the boundary of areas 

 that may meet the hydric soil criterion. 

 Verify the presence of hydric soil within 

 the appropriate map units by digging a 

 nxmiber of holes at least 18 inches deep 

 along the boundary (interface) between 

 hydric soil units and nonhydric soil 

 units. Compare soil samples with 

 descriptions in the soil survey report to 

 see if they are properly mapped. In this 

 way, the boundary of areas meeting the 

 hydric soil criterion is further refined by 

 field observations. In map units where 

 only part of the unit is hydric (e.g., 

 complexes, associations, and 

 inclusions), locate hydric soil areas on 

 the ground by considering landscape 

 position and evaluating soil 

 characteristics for hydric soil properties. 

 (Note: Some hydric soils, especially 

 organic soils, have not been given a 

 series name and are referred to by 

 common names, such as peat, muck, 

 swamp marsh, wet alluvial land, tidal 

 marsh, Sulfaquents, and Sulfihemists. 

 These areas are also considered hydric 



soil map units. Certain hydric soils are 

 mapped with nonhydric soils as an 

 association or complex, while other 

 hydric soils occur as inclusions in 

 nonhydric map units. Only the hydric 

 soU portion of these map units should be 

 evaluated for the hydrophytic vegetation 

 criteria in Step 7.) If the area meets the 

 hydric soil criterion, proceed to Step 5. 

 Step 5. Consider the following: 



(1) Is the area presenUy lacking 

 hydrophytic vegetation or hydrologic 

 indicators due to annual, seasonal or 

 long-term fluctuations in precipitation, 

 surface water, or ground-water levels? 



(2) Are hydrophytic vegetation 

 indicators lacking due to seasonal 

 fluctuation is temperature (e.g., 

 seasonality of plant growth)? 



If the answer to either of these 

 questions is YES or uncertain, and the 

 area meets the description of one of the 

 exceptions to the three criteria, proceed 

 to the appropriate section of this 

 manual. If the answer to both questions 

 is NO. normal conditions are assumed to 

 be present, so proceed to Step 6. 



Note: In some cases, normal climatic 

 conditions, such as snow cover or frozen 

 soils, may prevent an accurate assessment of 

 the wetland criteria; one must use best 

 professional judgement to determine if 

 delaying the wetland delineation is 

 appropriate. 



Step 6. Select representative 

 observation area(s). Identify one or 

 more observation areas that represent 

 the area(s) meeting the hydric soil 

 criterion. A representative observation 

 area is one in which the apparent 

 characteristics (determined visually) 

 best represent characteristics of the 

 entire community. Mark the 

 approximate location of the observation 

 area(s) on the aerial photo. Proceed to 

 Step 7. 



Step 7. Characterize the plant 

 community v/ithin the area(3) meeting 

 the hydric soil criterion. Visually 

 estimate the percent areal cover of 

 dominant species for the entire plant 

 community. If dominant species are not 

 obvious, use one of the other onsite 

 meUiods. Proceed to Step 8 or to another 

 method, as appropriate. 



Step 8. Record the indicator status of 

 dominant species within each area 

 meeting the hydric soil criterion. 

 Indicator status is obtained from the 

 interagency Federal list of plants 

 occurring in weUands for the 

 appropriate geographic region. Record 

 information on an appropriate data 

 form. Proceed to Step 9. 



Step 9. Determine whether weUand is 

 present or additional analysis is 

 required. If the estimated percent areal 

 cover of OBL and FACW species 



