Federal Register / Vol. 56. No. 157 / Wednesday. August 14. 1991 / Proposed Rules 40471 



(Caution: Certain exceptions to the three 

 criteria may not meet the hydrology criterion; 

 see discussion of these areas.) 



Step 13. Make the wetland 

 determination for the sample plot. 

 Examine the data forms for the plot. 

 When the plot meets the hydrophytic 

 vegetation, hydric soil, and wetland 

 hydrology criteria, it is considered 

 wetland. Complete the summary data 

 sheet; proceed to Step 14 when 

 continuing to sample transects, or to 

 Step 15 when determining a boundary 

 between wetland and nonwetland 

 sample plots. 



(Note: Double check all data sheets to 

 ensure that they are completed properly 

 before going to another plot.} 



Step 14. Take other samples along the 

 transect. Repeat Steps 5 through 13, as 

 appropriate. When sampling is 

 completed for this transect proceed to 

 Step 15. 



Step 15. Determine the wetland- 

 nonwetland boundary point along the 

 transect. When the transect contains 

 both wetland and nonwetland plots, 

 then a boundary must be established. 

 Proceed along the transect from wetland 

 plot toward the nonwetland plot. Look 

 for the occurrence of UPL and FACU 

 species, the appearance of nonhydric 

 soil types, subtle changes in hydxologic 

 indicators, and/or slight changes in 

 topography. When such features are 

 noted, evaluate the three criteria and 

 locate the weUand-nonwetland 

 boundary (i.e.. the point at which one of 

 the three weUand hydrology criterion is 

 no longer met; make sure, however, that 

 this area does not qualify as a problem 

 area wetland). Establish new sample 

 plots on each side of the boundary (e.g., 

 within 50 feet) and repeat Steps 8 

 through 12. If existing plots are writhin a 

 reasonable distance of the boundary, 

 additional plots may not be necessary, 

 but always dociunent the features that 

 were used to identify the boundary. 

 Data sheets should be completed for 

 each plot. Mark the position of the 

 wetland boundary point on the base 

 map or photo and place a surveyor flag 

 or stake at the boimdary point in the 

 field, as necessary. Continue along the 

 transect imtil the boundary points 

 between all weUand and nonwetland 

 plots have been established. 



(Caution: In areas with a high interspersion 

 of wetland and nonwetland plant 

 communities, several boundary 

 determinaUons will be required.) 



When all wetland determinations 

 along this transect have been completed, 

 proceed to Step 16. 



Step 16. Sample other transects and 

 make weUand determinations along 

 each. Repeat Steps 5 through 15 for each 



remaining transect. When wetland 

 boimdary points for all transects have 

 been established, proceed to Step 17. 



Step 17. Determine the weUand- 

 nonwetland boundary for the entire 

 project area. Examine all completed 

 copies of the data sheets and mark the 

 location of each plot on the base map or 

 photo. Identify each plot as either 

 wetland (W) or nonwetland (N) on the 

 map or photo. If all plots are wetlands, 

 then the entire project area is wetland, if 

 all plots are nonwetlands, then the 

 entire project area is nonwetland. if 

 both wetland and nonwetland plots are 

 present, identify the boundary points on 

 the base map or on the ground, and 

 connect these points on the map by 

 generally following contour lines to 

 separate wetlands from nonwetlands. 

 Confirm this boundary on the groimd by 

 walking the contour lines between the 

 transects. Should anomalies be 

 encountered, it wrill be necessary to 

 establish short transects in these areas 

 to refine the boundary, apply Step 15. 

 and make any necessary adjustments to 

 the boundary on the base map and/or 

 on the ground. It may be worthwhile to 

 place surveyor flags or stakes at the 

 boundary points, especially when 

 marking the boundary for subsequent 

 surveying by engineers. 



Point Intercept Sampling Procedure 



The point intercept sampling 

 procedure is a frequency analysis of 

 vegetation used in areas that may meet 

 the hydric soil and wetland hydrology 

 criteria. It involves first identifying 

 areas that may meet the hydric soil and 

 wetland hydrology criteria writhin the 

 area of concern and then refining the 

 boundaries of areas that may meet the 

 hydric soil criterion for further 

 examination. Transects are then 

 established for analyzing vegetation and 

 determining whether hydrophytic 

 vegetation criterion is met by calculating 

 a prevalence index. 



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 Service 

 slides, soil surveys, NWI maps, and 

 other maps and photographs. 



(Note: This step is more convenient to 

 perform offsite, but may be done onsite; some 

 modification of study area lines may be 

 required after seeing the site in the field). 



Areas that may meet the hydric soil 

 criterion should be stratified into areas 

 of similar soils and similar vegetation 

 lifeforms (e.g., forested wetland, shrub 



wetland, and emergent wetland) for 

 further analysis. Proceed to Step 2. 



Step 2. Scan the areas that may meet 

 the hydric soil criterion and determine if 

 disturbed conditions exist. Are any 

 significantly disturbed areas present? If 

 YES, identify their limits for they should 

 be evaluated separately for wetland 

 determination purposes (usually after 

 evaluating undisturbed areas). Refer to 

 the section on disturbed areas, if 

 necessary, to evaluate the altered 

 characteristic(s) (vegetation, soils, or 

 hydrology), 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 

 cultivation.) 



Keep in mind that if at any time 

 during this determination one or more of 

 these three characteristics is found to 

 have been significantly altered, the 

 disturbed area wetland determination 

 procedures should be followed. If the 

 area is not significandy disturbed, 

 proceed to Step 3. 



Step 3. Scan the areas that may meet 

 the hydric soil criterion and determine Lf 

 obvious signs of weUand hydrology or 

 hydric soil are present. The weUand 

 hydrology criterion is met for any area 

 or portion thereof where, it is obvious or 

 knovm that the area is frequenUy 

 inundated or saturated at the surface 

 during the growing season. Confirm the 

 presence of hydric soil by examining the 

 soU for appropriate properties and take 

 note of dominant plants which should 

 easily meet the hydrophytic vegetation 

 criterion. If the area's hydrology has not 

 been significantly modified and the soil 

 is organic (Histosols. except Folista) or 

 is mineral classified as Sulfaquents, 

 Hydraquents. or Histic Subgroups of 

 Aquic Suborders according to "Soil 

 Taxonomy", and the area has 

 hydrophytic vegetation, then the area is 

 considered weUand. Hydrophytic 

 vegetation should be fairly obvious in 

 these situations. Areas lacking obvious 

 indicators of weUand hydrology, hydric 

 sods, or hydrophytic vegetation must be 

 further examined, so proceed to Step 4. 



Step 4. Refine Uie boundary of areas 

 that meet Uie hydric soil criterion. Verify 

 the presence of hydric soil within the 

 appropriate map units by digging a 

 number of holes at least 18 inches deep 

 along the boundary (interface) between 

 hydric soil units and nonhydric soU 

 units. Compare soil samples with 

 descriptions in Uie soil survey report to 

 see if they are properly mapped, and 

 look for soil properties caused by 



