diff --git a/ROMSPath.f90 b/ROMSPath.f90
index d3e4b1e..ac3f130 100644
--- a/ROMSPath.f90
+++ b/ROMSPath.f90
@@ -344,6 +344,7 @@ subroutine ini_ROMSPath()
         par(n,pVort) = 0.0
         par(n,pbehaveW) = 0.0
         par(n,pSSF) = 0.0
+        par(n,pWD) = 9999.0
 		
 		Ipar(n)=0.0
 		Jpar(n)=0.0
diff --git a/advection_module.f90 b/advection_module.f90
index 0c88923..bd7d3e8 100644
--- a/advection_module.f90
+++ b/advection_module.f90
@@ -165,6 +165,8 @@ SUBROUTINE find_currents(Xpar,Ypar,Zpar,ex,ix,ng,ets,Uad,Vad,Wad,tdepth,zeta)
 	  !*******************************
       ! ! !Check if particle location above or below boundary, If so, place
       ! ! !  just within boundary (1 mm)
+	  
+
       if (Zpar.LT.tdepth) then
         Zpar = tdepth + DBLE(0.001)
         !IF(TrackCollisions) hitBottom(n) = hitBottom(n) + 1
diff --git a/boundary_module.f90 b/boundary_module.f90
index 1da593b..63a09bd 100644
--- a/boundary_module.f90
+++ b/boundary_module.f90
@@ -149,7 +149,8 @@ SUBROUTINE zbounds(ng,Ipar,Jpar,Zpar,ingrid,t)
   use param_mod,    only: xi_rho,eta_rho	
   use INT_MOD,   only:   getInterp2D
   IMPLICIT NONE
-  DOUBLE PRECISION,  INTENT(IN) :: Ipar,Jpar,Zpar
+  DOUBLE PRECISION,  INTENT(IN) :: Ipar,Jpar
+  DOUBLE PRECISION,  INTENT(INOUT) :: Zpar
   INTEGER :: I,J
   INTEGER, INTENT(IN) :: ng ,t
   LOGICAL, INTENT(OUT) :: ingrid
@@ -167,6 +168,12 @@ SUBROUTINE zbounds(ng,Ipar,Jpar,Zpar,ingrid,t)
 			ingrid=.TRUE.
 		endif
 		
+		if (Zpar.GE.tzeta) then
+		    Zpar=tzeta-0.01D0 !set particle depth to 1 less than 
+			ingrid=.TRUE.
+		endif
+		
+		
 	endif
 	
 END SUBROUTINE zbounds
diff --git a/interpolation_module.f90 b/interpolation_module.f90
index 4e44951..f37020d 100644
--- a/interpolation_module.f90
+++ b/interpolation_module.f90
@@ -1224,9 +1224,17 @@ SUBROUTINE getcoeff(X,Y,m,cff)
 		W(4)=m(4)/dist(4)
 	    WT=W(1)+W(2)+W(3)+W(4)
 		
-		do i=1,4 
-			cff(i)=W(i)/WT
-		enddo
+		
+		if ( WT.EQ.0.0D0) then
+			do i=1,4 
+				cff(i)=0.0D0
+			enddo		
+		else
+			do i=1,4 
+				cff(i)=W(i)/WT
+			enddo
+		endif
+