U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8444525 PUBLICATION DATE: 04/21/2003 Name: NUT ISLAND, QUINCY BAY MA NOAA Chart: 13270 Latitude: 42° 16.8' N ( 42.28000) USGS Quad: HULL Longitude: 70° 57.2' W ( -70.95330) To reach the tidal bench marks from I-93 South in Boston, take Exit 12 to Route 3A South and bear left to the Squantum/Wollaston Beach exit and Sea Street, then go 5.0 km (3.1 mi) to the entrance of the Nut Island Headworks facility. The bench marks are on the property of the headworks facility. The tide gage was located on the inshore end of the concrete pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NI 8 DESIGNATION: 844 4525 NI 8 MONUMENTATION: Survey disk VM#: 16249 AGENCY: Massachusetts Geodetic Survey (MGS) IDB PID#: SETTING CLASSIFICATION: Concrete pier OPUS PID: LATITUDE: 42° 16.9' N ( 42.28170) LONGITUDE: 70° 57.2' W ( -70.95330) The primary bench mark is a disk set flush in the concrete cap on the east side of the Nut Island headworks pier, 25.02 m (82.1 ft) south of the north end of the pier, 6.49 m (21.3 ft) north of the center of a bollard, 3.41 m (11.2 ft) east of the center of the pier, and 1.07 m (3.5 ft) west of the east edge.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8444525 PUBLICATION DATE: 04/21/2003 Name: NUT ISLAND, QUINCY BAY MA NOAA Chart: 13270 Latitude: 42° 16.8' N ( 42.28000) USGS Quad: HULL Longitude: 70° 57.2' W ( -70.95330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4525 A 2000 DESIGNATION: 844 4525 A MONUMENTATION: Tidal Station disk VM#: 16250 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete pier OPUS PID: LATITUDE: 42° 16.9' N ( 42.28170) LONGITUDE: 70° 57.2' W ( -70.95330) The bench mark is a disk set flush in the concrete cap on the east side of the Nut Island headworks pier, 24.81 m (81.4 ft) NW of the second light pole on the east side of the pier, 9.63 m (31.6 ft) NE of the first light pole on the pier, 4.11 m (13.5 ft) south of the center of the pier, and 0.46 m (1.5 ft) west of the east edge of the pier. BENCH MARK STAMPING: 4525 B 2000 DESIGNATION: 844 4525 B MONUMENTATION: Tidal Station disk VM#: 16251 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete well cap OPUS PID: LATITUDE: 42° 16.8' N ( 42.28000) LONGITUDE: 70° 57.2' W ( -70.95330) The bench mark is a disk set in a concrete well cap with four goose necked vent pipes on the NE side of the facility building, 25.79 m (84.6 ft) NNE of the SE corner of a chainlink fence around a parking lot, 25.51 m (83.7 ft) SSE of the centerline of the road leading to the pier, 11.80 m (38.7 ft) SE of the NE corner of the fence, 8.41 m (27.6 ft) east of the side of the fence, and 0.40 m (1.3 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8444525 PUBLICATION DATE: 04/21/2003 Name: NUT ISLAND, QUINCY BAY MA NOAA Chart: 13270 Latitude: 42° 16.8' N ( 42.28000) USGS Quad: HULL Longitude: 70° 57.2' W ( -70.95330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4525 C 2000 DESIGNATION: 844 4525 C MONUMENTATION: Tidal Station disk VM#: 16252 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete pad OPUS PID: LATITUDE: 42° 16.7' N ( 42.27830) LONGITUDE: 70° 57.3' W ( -70.95500) The bench mark is a disk set in the NW corner of a 3.00 m (9.8 ft) x 4.30 m (14.1 ft) concrete pad with steel doors and a 0.95 m (3.1 ft) x 0.95 m (3.1 ft) stainless vent, on the NW side of the facility building and near the bike path, 44.50 m (146.0 ft) NE of a stainless vent, 20.20 m (66.3 ft) NNW of the westerly of two flagpoles in front of the building, 3.60 m (11.8 ft) ESE of a asphalt bike path, and at ground level. BENCH MARK STAMPING: 4525 D 2000 DESIGNATION: 844 4525 D MONUMENTATION: Tidal Station disk VM#: 16253 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete pad OPUS PID: LATITUDE: 42° 16.8' N ( 42.28000) LONGITUDE: 70° 57.2' W ( -70.95330) The bench mark is a disk set flush in a concrete pad for a 4 ft (1 m) square stainless steel vent, on the north side of the property on a small hill, 137 m (450 ft) NWof the facility building, 36.55 m (119.9 ft) NNW of an asphalt jogging trail, 20.00 m (65.6 ft) east of a jogging trail, and 4.60 m (15.1 ft) west of a concrete and steel vent.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8444525 PUBLICATION DATE: 04/21/2003 Name: NUT ISLAND, QUINCY BAY MA NOAA Chart: 13270 Latitude: 42° 16.8' N ( 42.28000) USGS Quad: HULL Longitude: 70° 57.2' W ( -70.95330) T I D A L D A T U M S Tidal datums at NUT ISLAND, QUINCY BAY based on: LENGTH OF SERIES: 14 Months TIME PERIOD: September 2000 - October 2001 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8443970 BOSTON, BOSTON HARBOR Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (03/06/2001) = 3.973 MEAN HIGHER HIGH WATER MHHW = 3.113 MEAN HIGH WATER MHW = 2.976 MEAN SEA LEVEL MSL = 1.574 MEAN TIDE LEVEL MTL = 1.540 MEAN LOW WATER MLW = 0.104 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (02/11/2001) = -0.954 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW NI 8 5.448 2.472 4525 A 2000 5.450 2.474 4525 B 2000 10.843 7.867 4525 C 2000 9.122 6.146 4525 D 2000 10.408 7.432
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8444525 PUBLICATION DATE: 04/21/2003 Name: NUT ISLAND, QUINCY BAY MA NOAA Chart: 13270 Latitude: 42° 16.8' N ( 42.28000) USGS Quad: HULL Longitude: 70° 57.2' W ( -70.95330) 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.