Proceed along the transect from the wetland plot 

 toward the nonwetland plot. Look for the occur- 

 rence of UPL species, the appearance of nonhydric 

 soil types, subtle changes in hydrologic indicators, 

 and/or slight changes in topography. When such 

 features are noted, establish a new sample plot and 

 repeat Steps 8 through 13. {Note: New data sheets 

 must be completed for this new plot.) If this area is 

 a nonwetland, move halfway back along the tran- 

 sect toward the last documented wedand plot and 

 repeat Steps 8 through 13, varying plot size as 

 appropriate. Condnue this procedure until the wet- 

 land-nonwetland boundary point is found. It is not 

 necessary to complete new data sheets for all inter- 

 mediate points, but data sheets should be complet- 

 ed for each plot immediately adjacent to the wet- 

 land-nonwedand boundary point (i.e., data sheets 

 for each side of the boundary). Mark the posirion 

 of the wetland boundary point on the base map or 

 photo and stake or flag the boundary in the field, as 

 necessary. Continue along the transect until the 

 boundary points between all wetland and nonwet- 

 land plots have been established. {CAUTION: In 

 areas with a high interspersion of wedand and non- 

 wetland plant communities, several boundary 

 determinarions will be required.) When all wedand 

 determinations along this transect have been com- 

 pleted, proceed to Step 17. 



Step 16. Determine the wetland-nonwetland 

 boundary between adjacent vegetation units. 

 Review all completed copies of the data sheets for 

 each vegetation unit. Identify each unit as either 

 wedand (W) or nonwedand (N). When adjacent 

 vegetation units contain bodi wedand and nonwet- 

 land communities, a boundary must be established. 

 Walk the interface between the two units from the 

 wedand unit toward the nonwedand unit and look 

 for changes in vegetation, soils, hydrologic indica- 

 tors, anchor elevation. As a general rule, at 100- 

 foot intervals or whenever changes in die vegeta- 

 tion unit's characteristics are noted, establish a new 

 observation area and repeat Steps 8 through 13. 

 {Note: New data sheets must be completed for diis 

 new area.) If this area is nonwedand, move back 

 down the gradient about halfway back toward the 

 wedand unit and make additional observations 

 along the interface until wetland is identified. 

 {Note: Soils often are more useful dian vegetation 

 in establishing the wetland-nonwedand boundary, 

 particularly if there is no obvious vegetation break 

 or when FAC plant species dominate two adjacent 

 vegetation units.) At each designated boundary 

 point, complete data sheets for areas immediately 



upslope and downslope of the wedand-nonwedand 

 boundary (i.e., one set for the wedand unit and one 

 for the nonwedand unit), record the distance and 

 compass directions between the boundary points 

 and their respective pair of soil samples. Mark the 

 position of the wetland boundary point on the base 

 map or photo and stake or flag die boundary in the 

 field, as necessary. Based on observations along 

 the interface, identify a host of boundary points 

 between each wedand unit and nonwedand unit. 

 Repeat this step for all adjacent vegetation units of 

 wedand and nonwedand. When wedand boundary 

 points between all adjacent wetland and nonwet- 

 land units have been established, proceed to Step 

 18. 



Step 17. Sample other transec-ts and make 

 wetland determinations along each. Repeat Steps 5 

 through 15 for each remaining transect. When wet- 

 land boundary points for all transects have been 

 established, proceed to Step 18. 



Step 18. Determine the wetland-nonwetland 

 boundary for the entire project area. Examine all 

 completed copies of die data sheets, and mark the 

 location of each plant community type along the 

 transect on die base map or photo, when used. 

 {Note: This has already been done for the vegeta- 

 tion unit approach.) Identify each plant community 

 as eidier wedand (W) or nonwedand (N), if it has 

 not been done previously. If all plant communities 

 are wedands, dien die entire project area is wet- 

 land. If all communities are nonwedands, then the 

 entire project area is nonwedand. If both wedands 

 and nonwedands are present, identify die boundary 

 points on die base map and connect diese points on 

 the map by generally following contour tines to 

 separate wedands from nonwetlands. Confirm this 

 boundary by walking the contour tines between the 

 transects or vegetation units, as appropriate. 

 Should anomaUes be encountered, it will be neces- 

 sary to establish short transects in these areas to 

 refine die boundary; make any necessary adjust- 

 ments to die boundary on die base map and/or on 

 the ground. It also may be wordiwhile to flag these 

 boundary points, especially when marking the 

 boundary for subsequent surveying by engineers. 



Comprehensive Onsite Determination 

 Method 



4.15. The comprehensive determination method is 

 the most detailed, complex, and labor-intensive 



39 



