EQUIPMENT AND SUPPLIES--Water Resources Division Policy on Phase-Out of Manometers

In Reply Refer To:
Mail Stop 460                                     Aug. 29, 1991


WATER RESOURCES DIVISION MEMORANDUM NO. 91.58

SUBJECT:  EQUIPMENT AND SUPPLIES--Water Resources Division Policy
                                   on Phase-Out of Manometers

The May 8, 1988, memorandum to Regional Hydrologists and District
Chiefs, subject, "Information--Manometer Support." stated that no
additional mercury manometers were to be purchased by the Water
Resources Division (WRD).  The policy of no manometer purchases
continues in effect.  Further, WRD policy now is that manometers no
longer may be deployed at new data-collection stations or installed
as replacement instruments at existing stations.  The Division has
set a goal for all manometers to be removed from data-collection
stations before October 1, 1997.

With encouragement by the Hydrologic Instrumentation Facility (HIF),
industry has developed a nonsubmersible transducer that can measure
water levels more accurately and reliably than the manometer.  The
new system, now available from the HIF, is controlled by a micro-
processor, which transmits digital data to an electronic data logger
or data-collection platform.  The HIF is continuing to work with
industry to obtain a low-cost submersible transducer system for the
measurement of water levels that also may be used as a replacement
for the manometer.  The HIF continues to test other sensors in an attempt
to find a reliable low-cost instrument that will meet the stage
measurement accuracy goal of +/-0.01 ft. for daily discharge stations
(see office of Surface Water Technical Memorandum No. 89.08).

The efforts described above were undertaken to provide better water-
level sensors and address an ever-growing concern over the need to
remove the mercury manometer from the gagehouse.  We have no firm
indication that the use of mercury in the field will be banned in the
short term; however, the Water Resources Division (WRD) must take the
initiative to phase out the use of mercury manometers.

The HIF is investigating the most cost-beneficial, approved means of
manometer and mercury disposal.  Pertinent guidelines and instructions
will be sent to WRD offices at a later date.  The Districts are
responsible for the 9-066 property control documents requesting
permission to dispose of the manometers.

We request that you include in your planning and negotiations with
cooperators, a multiyear replacement plan for manometers.  WRD will
help facilitate the Districts' purchase of the new pressure sensor-
recorder system in fiscal years 1993 and 1994 by eliminating the
HIF overhead.

Districts may assume ownership of the equipment or apply the purchase
costs as a 4-year HIF lease credit.  Districts may purchase the non-
submersible transducer (PS-2) with or without a data-collection plat-
form (DCP) or electronic data-logger (EDL).  The PS-2 must be operated
with a DCP or EDL that supports SDI-12 (serial digital interface).  The
PS-2 includes a Y-cable and gas-purge component.  Districts are
responsible for providing the gas cylinder, orifice, orifice line, and
other support items.

The estimated purchase costs for fiscal years 1993 and 1994 are listed
below.

Fiscal Year   PS-2 Sensor Only   PS-2 with DCP   PS-2 with EDL
  1993             $4500           $8200            $5800
  1994             $4700           $8500            $6000

Please contact Jim Futrell at FTS 494-1537 if you have any questions
or require information on the new pressure sensor system.

                                        William B. Mann IV

Distribution: A,B,S,FO,PO

This memorandum does not supersede any previous memorandum.

KEY WORDS:  Manometer, Mercury