U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                   PUBLICATION DATE:  06/16/1988
Station ID: 8546252                                SUPERCEDED DATE:   04/21/2003
Name:       BRIDESBURG, DELAWARE RIVER                        
            PENNSYLVANIA
NOAA Chart: 12314                                  Latitude:         39° 59.0' N
USGS Quad:  CAMDEN                                 Longitude:        75°  4.5' W


To reach the tidal bench marks from Interstate Highway 95 North and the
Allegheny Avenue Exit in Philadelphia, proceed off the exit ramp and turn right
at Bath Avenue, bear around the curve for 0.2 mile (0.3 km) to Allegheny Avenue,
turn left at the stop sign and go 0.2 mile (0.3 km) to Delaware Avenue, bear
left around the curve and go 1.3 miles (2.1 km) to Lewis Street, turn right onto
Lewis Street and go 0.1 mile (0.2 km) to the gate house of the Philadelphia
Electric Richmond station.  The bench marks are behind the main plant building. 
The tide gage and staff were on the SW face of the main pier (225N) behind the
main plant building at the second yellow bollard from the main plant ground.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  ELEV + 12.00 FT AUGUST 1956 A

MONUMENTATION:           Survey Disk                               VM#:     2949
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Building Wall


The bench mark is set vertically on the SE wall face at the south corner of the
main plant building, 60.3 feet (18.4 m) NW of the most northwestern rail of a
set of railroad tracks running NE - SW, 32.5 feet (9.9 m) SW of the center point
of a red fire hydrant set into the SE face of the main plant building, 24.8 feet
(7.6 m) NE of the most northeastern rail of a set of railroad tracks running NW
- SE, 0.3 foot (0.1 m) NE of the south corner of the main plant building, and
3.6 feet (1.1 m) above ground level.



                         BENCH MARK STAMPING:  ELECTRIC RM 2 1925

MONUMENTATION:           Survey Disk                               VM#:     2946
AGENCY:                                                            PID#:  AE5614
SETTING CLASSIFICATION:  Concrete Pier


The bench mark is at the SE end of concrete Pier 225N, 18.6 feet (5.7 m) SW of
Bench Mark ELECTRIC 2 1978, and 2.2 feet (0.7 m) NW of the SE face of the pier.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                   PUBLICATION DATE:  06/16/1988
Station ID: 8546252                                SUPERCEDED DATE:   04/21/2003
Name:       BRIDESBURG, DELAWARE RIVER                        
            PENNSYLVANIA
NOAA Chart: 12314                                  Latitude:         39° 59.0' N
USGS Quad:  CAMDEN                                 Longitude:        75°  4.5' W


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  ELECTRIC 2 1978

MONUMENTATION:           Survey Disk                               VM#:     2947
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Pier


The bench mark is located at the SE end of concrete Pier 225N, 15.1 feet (4.6 m)
south of Bench Mark ELECTRIC 2 NO 3 1978, 4.2 feet (1.3 m) NW of the SE face of
the pier, and 3.4 feet (1.0 m) west of the large black mooring post (bolland)
which is at the east corner of the pier.



                         BENCH MARK STAMPING:  ELECTRIC 2 NO 3 1978

MONUMENTATION:           Survey Disk                               VM#:     2948
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Pier


The bench mark is at the SE end of concrete Pier 225N, 27.8 feet (8.5 m) NNE of
Bench Mark ELECTRIC RM 2 1925, 18.0 feet (5.5 m) NW of the SE face of the pier,
and 3.4 feet (1.0 m) SW of the NE face of the pier.



                         BENCH MARK STAMPING:  ELEV + 12.00 FT AUGUST 1956 B

MONUMENTATION:           Survey Disk                               VM#:     2950
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Tower Wall


The bench mark is set vertically on the NW face of a coal tower on Pier 225N, SW
of the most southwestern archway leading under the tower to the Delaware River,
71.5 feet (21.8 m) south of the south corner of the guard house under the
overhead walkway at the entrance to the pier 10.8 feet (3.3 m) SW of the most
southwestern rail of the set of railroad tracks running NW - SE, 5.8 feet (1.8
m) SE of a large mooring post (bollard) 4.0 feet (1.2 m) NE of the SW face of
the pier, and 4.1 feet (1.2 m) above ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                   PUBLICATION DATE:  06/16/1988
Station ID: 8546252                                SUPERCEDED DATE:   04/21/2003
Name:       BRIDESBURG, DELAWARE RIVER                        
            PENNSYLVANIA
NOAA Chart: 12314                                  Latitude:         39° 59.0' N
USGS Quad:  CAMDEN                                 Longitude:        75°  4.5' W


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  ELEV + 12.00 FT AUGUST 1956 C

MONUMENTATION:           Survey Disk                               VM#:     2951
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Tower Wall


The bench mark is set vertically on the NW face of a coal tower on Pier 225N, NE
of the most northeastern archway leading under the tower to the Delaware River,
10.0 feet (3.0 m) NE of the centerline of the most northeastern rail of a set of
railroad tracks running NW - SE, 5.9 feet (1.8 m) SE of a mooring post (bollard)
4.2 feet (1.3 m) SW of the NE face of the pier, 1.1 feet (0.3 m) SW of the north
corner of the tower and 4.2 feet (1.3 m) above ground level.



                         BENCH MARK STAMPING:  ELEV + 12.00 FT AUGUST 1956 D

MONUMENTATION:           Survey Disk                               VM#:     2952
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Building Wall


The bench mark is set vertically on a thin metal strip which is screwed into the
NW face of a 1-1/2 story concrete building SE of the main plant building, 171.5
feet (52.3 m) east of Bench Mark ELEV + 12.00 FT USC&GS DATUM AUGUST 1956 A,
20.6 feet (6.3 m) SW of the north corner of the building, 11.5 feet (3.5 m) SE
of the centerline of the most southeastern rail of a set of railroad tracks
running NE - SW, 3.2 feet (1.0 m) NE of the NE side of a doorway leading into
the building, and 3.5 feet (1.1 m) above ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                   PUBLICATION DATE:  06/16/1988
Station ID: 8546252                                SUPERCEDED DATE:   04/21/2003
Name:       BRIDESBURG, DELAWARE RIVER                        
            PENNSYLVANIA
NOAA Chart: 12314                                  Latitude:         39° 59.0' N
USGS Quad:  CAMDEN                                 Longitude:        75°  4.5' W


                            T I D A L   D A T U M S 


Tidal datums at BRIDESBURG, DELAWARE RIVER based on:

     LENGTH OF SERIES:      10 MONTHS
     TIME PERIOD:           MARCH 1984 - JANUARY 1985
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8545530 PHILADELPHIA


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:

     HIGHEST OBSERVED WATER LEVEL (04/06/1984)         =   9.58
     MEAN HIGHER HIGH WATER                     MHHW   =   6.97
     MEAN HIGH WATER                            MHW    =   6.58
     MEAN TIDE LEVEL                            MTL    =   3.39
     MEAN LOW WATER                             MLW    =   0.20
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (01/21/1985)         =  -2.41

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     ELEV + 12.00 FT AUGUST 1956 A              14.32      7.74
     ELECTRIC RM 2 1925                         10.20      3.62
     ELECTRIC 2 1978                            10.15      3.57
     ELECTRIC 2 NO 3 1978                       10.09      3.51
     ELEV + 12.00 FT AUGUST 1956 B              14.35      7.77
     ELEV + 12.00 FT AUGUST 1956 C              14.33      7.75
     ELEV + 12.00 FT AUGUST 1956 D              14.36      7.78


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                   PUBLICATION DATE:  06/16/1988
Station ID: 8546252                                SUPERCEDED DATE:   04/21/2003
Name:       BRIDESBURG, DELAWARE RIVER                        
            PENNSYLVANIA
NOAA Chart: 12314                                  Latitude:         39° 59.0' N
USGS Quad:  CAMDEN                                 Longitude:        75°  4.5' W


                             D E F I N I T I O N S


Mean Sea Level (MSL) is a tidal datum determined over a 19-year National Tidal
Datum Epoch.  It pertains to local mean sea level and should not be confused
with the fixed datums of North American Vertical Datum of 1988 (NAVD88).

NAVD88 is a fixed datum derived from a simultaneous, least squares, minimum
constraint adjustment of Canadian/Mexican/United States leveling observations.
Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as
the single initial constraint.  NAVD88 replaces NGVD29 as the national
standard geodetic reference for heights.  Bench mark elevations relative to
NAVD88 are available from NGS through the World Wide Web at 
National Geodetic Survey.

NGVD29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded.  NGVD29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads.  NGVD29 was originally derived from a general
adjustment of the first-order leveling networks of the U.S. and Canada after
holding mean sea level observed at 26 long term tide stations as fixed.
Numerous local and wide-spread adjustments have been made since establishment in
1929.  Bench mark elevations relative to NGVD29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at 
National Geodetic Survey.

NAVD88 and NGVD29 are fixed geodetic datums whose elevation relationships to
local MSL and other tidal datums may not be consistent from one location to
another.

The Vertical Mark Number (VM#) and PID# shown on the bench mark sheet are unique
identifiers for bench marks in the tidal and geodetic databases, respectively.
Each bench mark in either database has a single, unique VM# and/or PID# assigned.
Where both VM# and PID# are indicated, both tidal and geodetic elevations are
available for the bench mark listed.

The NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD88 elevations.
The NAVD88 elevation relationship shown in the table is derived from an average
of several bench mark elevations relative to tide station datum.  As a result of
this averaging, NAVD88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD88 elevations listed for
each bench mark in the NGS database.