August 2002 

Submetering of Water - a Growing Concern 

By: Steven Cook 

The Weights and Measures Division has received several inquiries from industry and 

weights and measures officials regarding the submetering of water. Additionally, the 

State of Virginia wrote an article published in the Southern Weights and Measures 

Association July 2002 Newsletter, about billing for water without the use of a meter. 

These issues are of concern to weights and measures officials and are a source of 

consumer complaints. 

Submetering is the practice of using meters; water, gas vapor, or electricity, to measure 

master metered utility consumption by individual users. A master meter, as used in the 

utility metering industry, is a utility meter typically owned, maintained, and read for 

billing purposes by the serving utility and supplies water (or other measured utility 

services) to multi-unit businesses and residences. Meters in these applications should 

not be confused with meters used as transfer standards. Submeters are installed at the 

individual units, residences or spaces in apartment complexes, mobile home parks 

(MHP), marinas, and short-term recreational vehicle parks that purchase water from a 

serving utility using a master meter. The owner of the complex, landlord, or a third party 

billing company resells the water and provides invoices to the residents or tenants. 

Recent interest in water metering is due to water conservation issues increasing the cost 

of water service thereby providing the incentive for the use of submeters and nonmetered water allocation charges for MHPs and multi-unit apartments. This has resulted 

in the installation of submeters and changes in billing practices. Additionally, local and 

regional rent control regulations, while limiting rent increases, may permit billing 

separately for utility costs when they previously were billed at a flat rate. Frequently, 

consumers who are billed separately for utilities use often (1) question the reason for 

certain water charges, (2) question the basis for calculating the charges, (3) complain they 

are being assessed improper, or illegal, charges for water service, (4) claim the water 

meters are inaccurate, or (5) claim the utility charges are another form of rent increase. 

Water utility meters typically fall under the jurisdiction of a State’s public utility 

commission or some other government municipality. Many of the State utility 

commissions have jurisdiction, in part, over submetered systems regarding the rates 

charged by the owner or landlord. Some jurisdictions may have a rule that landlords may 

charge the tenant no more than the amount that would be charged to a similar resident 

served directly by the utility. Additionally, some State public utility commissions and 

municipalities have no jurisdiction over the devices used in submetering, leaving 

compliance with performance and accuracy requirements to the state’s weights and 

measures department. 
In California, for example, the Public Utilities Commission’s (CPUC) General Order 103 

sets the standards for water meters and for meter reading applicable to CPUC-regulated 

water corporations up to and including the master meter. The standards for submeters at 

multi-unit apartments or MHPs fall within the province of the Division of Measurement 

Standards (DMS) within the California Department of Food and Agriculture (unless the 

meter is owned, serviced, and read by the serving utility or municipality). 

MHPs and apartment owners may feel it would be a costly proposition to install separate 

submeters at existing locations (up to $200 per unit) to recover increased water costs, and 

unmetered water usage promotes waste. This has led MHPs and apartment owners to use 

an alternative method to metered consumption to cover increased water costs. Landlords 

started using apartment square footage or number of tenants per unit as proxies for usage 

and imposed a separate water (and sometimes sewer) charge on that basis. These proxies 

are generally known as “RUBS,” or Residential or Ratio Utility Billing Systems. MHP 

residents and apartment tenants have complained that the RUBS systems are flawed and 

do not accurately represent water usage. Tenants who make sincere efforts to conserve 

water pay the same as similar sized apartments with the same number of occupants who 

do not conserve water. Additionally, this method of representing water usage may be a 

violation of a State’s method of sale law that requires that representations of water usage 

must be determined by measuring devices and not the use of alternate methods that infer 

actual consumption based upon a unit’s number of occupants and/or square footage. As 

stated in the July 2002 SWMA newsletter, the State of Virginia Weights and Measures 

Law requires liquids to be sold by measure. The Virginia State Attorney General also 

stated tenants could not enter into contracts that circumvent the law. 

Submeter installation problems have also been reported. Meters designed to standards 

other than NIST Handbook 44 have been installed as submeters. Some of the standards 

developed by the American Water Works Association (AWWA), such as AWWA C700-

900 Cold Water Meters – Displacement Type, Bronze Main Case, are identical to 

Handbook 44 water meter tolerances. However, some AWWA standards for water 

meters, such as AWWA C712-02 Cold Water Meters – Single Jet Type, and AWWA 

C708-96 for Cold Water Meters – Multi-jet Type, have tolerances different than 

Handbook 44. The maximum and intermediate flow rate tolerances are the same (98.5 % 

to 101%) for the different types water meters. However, tolerances at the minimum flow 

rates differ. For example, displacement type meters have a minimum flow tolerance of 

95% to 101% (equivalent to Handbook 44) where multi-jet meters have a minimum flow 

rate tolerance of 97% to 103% (AWWA C708-96). The tolerances in AWWA standards 

often vary on design and category of different water measurement technologies, whereas 

Handbook 44 contains water meter performance standards not dependent on a specific 

water meter technology. 

Measuring devices have also been installed where no Handbook 44 requirements exist. 

Some apartment owners have installed separate hot water meters in an attempt to infer 

total water usage and energy costs for heating the water. Another type of meter is the 

small “point-of-use” water meter that can be installed on every water outlet in an 

apartment or mobile home. At the 87th NCWM Annual Meeting, Handbook 44 was 
amended to recognize the size of these “point-of-use” meters and their remote meter 

reading capability. 

The orientation of a submeter (or water meter) should also be a concern. The California 

DMS has noted and documented that the performance of water meters can be affected 

depending on the orientation of the meter. Testing by DMS has proven some types of 

water meters can perform within tolerance if they are installed in a horizontal and level 

position, but fail tolerances when tested in a vertical or out of level condition. Handbook 

44 General Code paragraph G-UR.2.1. Installation states a “device installed at a fixed 

location shall be installed so that neither its operation nor its performance will be 

adversely affected by any characteristic of the foundation, supports, or any other detail of 

the installation.” AWWA standards do not address testing in a horizontal or any other 

position. 

Weights and measures officials may receive consumer complaints because of the 

increased use of submeters and changes in water utility invoicing and may want to 

consider the following when investigating consumer complaints. Does the transaction 

fall under the jurisdiction of the local weights and measures department? If the answer is 

no, weights and measures can still help by providing the consumer with a contact name 

and number of the serving utility, municipality, water board or other agency with 

jurisdiction over the submeter installation. A local or State housing and community 

development department or mobile home owners associations may be able to provide 

assistance. State utility commissions may have laws requiring utilities to investigate 

consumer complaints and keep records of all complaints. Additionally, new tenants can 

be encouraged to review the rental agreement for an explanation of utility billing 

provisions. 

In weights and measures jurisdictions that have authority over utility submeters, the 

official should obtain a copy of the invoice and accurately read the meter. Inaccurately 

reading the meter, either at the beginning or the end of the billing cycle, or incorrectly 

calculating the water usage or total price, are frequent reasons for consumer complaints 

of high water utility bills. All information used to calculate the invoice should be 

included on the invoice, posted by the complex management, or described in the tenant’s 

contract. The accuracy of the meter should be verified if the official determines the meter 

was read correctly and the consumer was invoiced accurately. Handbook 44 Water Meter 

Code Notes provide guidance to the official for the size of test drafts and water meter test 

procedures. 

If you have additional information regarding water submetering in your jurisdiction, 

please contact Steve Cook by phone at (301) 975-4003 or by email at 

steven.cook@nist.gov.