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

                                                                                
Station ID: 8531262                         PUBLICATION DATE:  07/15/2003
Name:       KEASBEY, RARITAN RIVER                            
            NJ
NOAA Chart: 12131                           Latitude:   40° 30.5' N (  40.50830)
USGS Quad:  PERTH AMBOY                     Longitude:  74° 18.7' W ( -74.31170)


To reach the tidal bench marks from the Garden State Parkway, exit at South
Amboy toll and proceed north on U.S. 9 across Raritan River to the first
stoplight at Smith Street, then proceed west on Smith Street for 1.6 km (1 mi)
to Crows Mill Road, then proceed south on Crows Mill Road to the Gallo Asphalt
Company.  Get permission before proceeding to extreme east end of the wharf. 
The bench marks are located near Crows Mill Road.  The tide gage and staff were
located on a wharf owned by this company.


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


                 PRIMARY BENCH MARK STAMPING:  1262 A 1975
                         DESIGNATION:          853 1262 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2518
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete pavement                     OPUS PID:        
LATITUDE:   40° 30.5' N (  40.50830)          LONGITUDE:  74° 18.7' W ( -74.31170)


The primary bench mark is a disk set flush in the concrete framework of a truck
scale located next to the 1-story frame office building of the Gallo Asphalt
Company, 18.50 m (60.7 ft) north of the south end of a concrete retaining wall,
13.84 m (45.4 ft) SE of the nearest corner of a 2 m (5 ft) high steel fence,
10.52 m (34.5 ft) west of a steel radio anetenna tower, 5.41 m (17.7 ft) SW of
the SE corner of the building, and 1.16 m (3.8 ft) south of the SE corner of the
building.

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

                                                                                
Station ID: 8531262                         PUBLICATION DATE:  07/15/2003
Name:       KEASBEY, RARITAN RIVER                            
            NJ
NOAA Chart: 12131                           Latitude:   40° 30.5' N (  40.50830)
USGS Quad:  PERTH AMBOY                     Longitude:  74° 18.7' W ( -74.31170)


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


                         BENCH MARK STAMPING:  1262 B 1975
                         DESIGNATION:          853 1262 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2519
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   40° 30.5' N (  40.50830)          LONGITUDE:  74° 18.7' W ( -74.31170)


The bench mark is a disk located at the Indiana General Electronic Division on
Crows Mill Road, 28.16 m (92.4 ft) SE of wood utility pole #12562WB, 23.91 m
(78.5 ft) SE of the SW corner of a square steel manhole cover, 17.74 m (58.2 ft)
north of the north corner of the main building entrance extension, and 1.43 m
(4.7 ft) east of the asphalt curb to the east of the parking area. The bench
mark is set 6 cm (0.2 ft) below ground level, and crimped to the top of a
copper-clad steel rod driven 9.1 m (30 ft) to refusal.



                         BENCH MARK STAMPING:  1262 C 1975
                         DESIGNATION:          853 1262 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2520
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID#: BBDC05
LATITUDE:   40° 30.5' N (  40.50830)          LONGITUDE:  74° 18.7' W ( -74.31170)


The bench mark is a disk located south of the Union Carbide Keasbey Plant on
Crows Mill Road, 18.57 m (60.9 ft) west of a wood utility pole on the west side
of Crows Mill Road, 12.13 m (39.8 ft) NE of a flagpole, 10.82 m (35.5 ft) SE of
the SW corner of the building in line with three trees, 6.16 m (20.2 ft) SW of
the SE corner of the main building.  The bench mark is set 6 cm (0.2 ft) below
ground level, and crimped to the top of a copper-clad steel rod driven 7.6 m (25
ft) to refusal.

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

                                                                                
Station ID: 8531262                         PUBLICATION DATE:  07/15/2003
Name:       KEASBEY, RARITAN RIVER                            
            NJ
NOAA Chart: 12131                           Latitude:   40° 30.5' N (  40.50830)
USGS Quad:  PERTH AMBOY                     Longitude:  74° 18.7' W ( -74.31170)


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


                         BENCH MARK STAMPING:  1262 D 1975
                         DESIGNATION:          853 1262 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2521
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   40° 30.5' N (  40.50830)          LONGITUDE:  74° 18.7' W ( -74.31170)


The bench mark is a disk located near the intersection of Smith Street and Crows
Mill Road north of the Union Carbide Keasbey Complex between two Lehigh Valley
railroad tracks, 33.62 m (110.3 ft) SE of the intersection point of the two
inside rails, 22.98 m (75.4 ft) north of a fire hydrant, 21.98 m (72.1 ft) NW of
utility pole #12557B, 18.23 m (59.8 ft) south of utility pole #60382WB.  The
bench mark is set at ground level, and crimped to the top of a copper-clad steel
rod driven 6.7 m (22 ft) to refusal.



                         BENCH MARK STAMPING:  1262 E 1975
                         DESIGNATION:          853 1262 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2522
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Building foundation                   OPUS PID:        
LATITUDE:   40° 30.5' N (  40.50830)          LONGITUDE:  74° 18.7' W ( -74.31170)


The bench mark is a disk set vertically in the south face of the building of the
Garden State Shipping Company located near the intersection of Smith Street and
Crows Mill Road, diagonally across from the Keasbey Post Office, 22.19 m (72.8
ft) SW of the SE corner of an 2 m (8 ft) high chain link fence enclosure, 21.85
m (71.7 ft) north of the east end of a steel guard rail, 14.87 m (48.8 ft) east
of the SE corner of the loading platform, and 0.58 m (1.9 ft) above the
pavement.

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

                                                                                
Station ID: 8531262                         PUBLICATION DATE:  07/15/2003
Name:       KEASBEY, RARITAN RIVER                            
            NJ
NOAA Chart: 12131                           Latitude:   40° 30.5' N (  40.50830)
USGS Quad:  PERTH AMBOY                     Longitude:  74° 18.7' W ( -74.31170)


                            T I D A L   D A T U M S 


Tidal datums at KEASBEY, RARITAN RIVER based on:

     LENGTH OF SERIES:      1 Year
     TIME PERIOD:           January 1976 - December 1976
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8531680 SANDY HOOK


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

     HIGHEST OBSERVED WATER LEVEL (08/09/1976)         =  2.395
     MEAN HIGHER HIGH WATER                     MHHW   =  1.749
     MEAN HIGH WATER                            MHW    =  1.647
     MEAN SEA LEVEL                             MSL    =  0.870
     MEAN TIDE LEVEL                            MTL    =  0.852
     MEAN LOW WATER                             MLW    =  0.058
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (02/02/1976)         = -1.427

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     1262 A 1975                                 3.974    2.327
     1262 B 1975                                 4.677    3.030
     1262 C 1975                                 6.333    4.686
     1262 D 1975                                11.877   10.230
     1262 E 1975                                13.663   12.016


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

                                                                                
Station ID: 8531262                         PUBLICATION DATE:  07/15/2003
Name:       KEASBEY, RARITAN RIVER                            
            NJ
NOAA Chart: 12131                           Latitude:   40° 30.5' N (  40.50830)
USGS Quad:  PERTH AMBOY                     Longitude:  74° 18.7' W ( -74.31170)


                             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 NGS's Integrated Data Base (IDB PID)
provides geodetic datum based on traditionally leveled and bluebooked ties to
the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/.
The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based
on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/.

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.