Why Monitor Chemicals?

Using a Force Flow Scale means SAFETY!

  • Accurately track daily chemical consumption
  • Prevent freezing up of vacuum regulator by giving an early warning of an excessive feed rate condition
  • Prevent systems from running empty by giving an early warning of a low level condition
  • 4-20mA remote monitoring reduces operator exposure to chemicals
  • Help track down leaks in your vacuum piping
  • Warn of open bypass valves or bypass valve failures
  • Assist in detecting and estimating the size of chlorine leaks
  • Pick up accidental transfer of chlorine from one tank to another in liquid feed systems
  • Prevent putting an empty tank "online" that is thought to be full
  • Roller trunnions allow rotation of tank to the gas phase in the event of a gas leak
  • Hi Feed rate alarm prevents overfeeding of controversial chemicals such as Fluoride
  • Low Feed rate alarm warns of vapor locked metering pumps in Hypo feed systems
  • Hi level alarm prevents overfilling of chemical day tanks


  • How do you know you are you getting all the chemical you paid for? Are you wasting chemical by overfeeding? Unless you have a weight-based level measuring system from Force Flow, you have no way of knowing.
  • Most chemicals are sold by weight, and you should be double-checking your supplier.
  • Some chemicals cost as much as $30-35 per gallon. You cannot afford to waste it!


Many Government Regulators, Industry Standards Groups and Trade Associations affiliated with the water and wastewater industry recommend or require using weighing scales to document chemical usage and inventory. Following is a small sampling of these regulatory bodies and the recommendations and requirements that are contained in their codes. As you can see, good engineering and safety practices include the use of a chemical weighing system for all chemicals used in the water and wastewater industry.

I. South Carolina Department of Health and Environmental Control's (DHEC) State Primary Drinking Water Regulations (SPDWR) September 2000 edition:

Section R.61-58.7,B(6) reads as follows "The operator shall measure the amounts of all chemicals used each day and calculate the dosages. The operator shall maintain a written record of all measurements and dosage calculations. The records shall be kept for a minimum of 3 years. "Additionally, Section R.61-58.7, B(9)j reads "Scales for weighing cylinders shall be calibrated yearly and properly maintained."

II. Environmental Protection Agency's Risk Management Program (RMP)
Section 112 (r), 40 C.F.R. Part 68: "All users storing in excess of 2500 lbs of Chlorine, 5000 lbs of Sulphur Dioxide and 10,000 lbs of Anhydrous Ammonia shall be required to file a Risk Management Program with the EPA." The best method of determining whether these thresholds have been exceeded is via a weighing scale.

III. Great Lakes Upper Mississippi River Board of State Public Health & Environmental Managers

Recommended Standards For Water Works 1997, ie "The 10 states standards": Part 5 Chemical Application, Section 5.1.2 (e) reads: "Provisions shall be made for measuring the quantities of chemicals used." Additionally, Section 5.1.2 (f) reads "Weighing scales: (1) shall be provided for weighing cylinders at all plants utilizing chlorine gas (2) may be required for fluoride solution feed (3) should be provided for volumetric dry chemical feeders, and (4) shall be capable of providing reasonable precision in relation to average daily dose."

IV. Great Lakes Upper Mississippi River Board of State Public Health & Environmental Managers
Recommended Standards For Wastewater Facilities 1997, i.e. "The 10 states standards": Chapter 100 Disinfection, Section 102.41 reads: "Scales: Scales for weighing cylinders and containers shall be provided at all plants using chlorine gas. At large plants, scales of the indicating and recording type are recommended. At least a platform scale shall be provided. The scales shall be of corrosion resistant material."

V. AWWA Manual M4: Water Fluoridation Principles and Practices Third edition:
Page 26 reads "In any fluoridation installation, except one based on a sodium fluoride saturator, scales are necessary for weighing the quantity of dry material to be used in preparing the solution, the quantity of solution fed, or the quantity of fluoride compound or hydrofluosilicic acid delivered by the appropriate feeder." In addition, Page 30 reads "Alarms: To prevent underfeeding or loss of feed, alarm systems can be included in either solution or dry feed systems. The alarm alerts the operator when the level of solution in the day tank is low or when it is time to add chemical."

VI. Compressed Gas Association's CGA G-2 Manual:
Page 36 section 8.9.1 reads "Determining when cylinders are empty-Weighing. The best way to determine if an ammonia cylinder is empty is to weigh it, without cap, and compare the weight with the tare weight stamped on the cylinder."

VII. The Chlorine Institutes Pamphlet 1 "The Chlorine Manual":
Page 10 Section 2.8.4 reads "Weighing-Because chlorine is shipped as a compressed liquefied gas, the pressure in a container depends on the temperature of the chlorine. The pressure is not related to the amount of chlorine in the container. Container contents can be determined accurately only by weighing."


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