mwra metering system & rates assessment overview

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MWRA METERING SYSTEM & RATES ASSESSMENT OVERVIEW

ADVISORY BOARD PRESENTATION

OCTOBER 18, 2012

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MWRA ASSESSMENT METHODOLOGIES

MWRA’s metro-system assessment methodologies allocates the annual (fiscal year) rate revenue requirement to the 55 communities and local bodies served by MWRA’s metropolitan water and sewer utilities.

Fiscal Year 2013 Current Expense Budget

EXPENSES (000’s): TOTALDirect Expenses $214,916Indirect Expenses $ 45,693Capital Expenses $375,248Total Expenses $635,857Other Revenue/Offsets $ 28,345Rate Revenue Requirement

WATER

$ 65,883$ 31,049$112,797$209,729$ 13,728

$196,001

SEWER

$149,032$ 14,644$262,452$426,127$ 14,617

$411,511$607,512

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How is the Water Rate Revenue Requirement allocated to MWRA

communities?

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WATER UTILITY ASSESSMENT

The Rate Revenue Requirement (RRR) for the MWRA Water Utility is allocated to member communities using the amount of metered water provided to each community in the most recent calendar year relative to the system as a whole.

Example:

Community’s Total Water Use Total Metro System-Wide Water Use

= Community’s System Share

Water Utility RRR x Community’s System Share = Assessment

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WATER UTILITY ASSESSMENT

Community CY2011 Water Use System Share FY2013 Assessment1

Boston (BWSC) 64.735 (mgd) 36.56% $71,651,462Quincy 8.935 (mgd) 5.05% $ 9,889,803

Newton 8.760 (mgd) 4.95% $ 9,695,370

Waltham 7.040 (mgd) 3.98% $ 7,792,300

Framingham 6.645 (mgd) 3.75% $ 7,355,228

SYSTEM TOTAL2 177.085 (mgd) 100% $196,001,401

1 Includes prior-year adjustments2 Includes only the rates-based communities in the metropolitan water system.

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WATER METER OVERVIEW

Water System· 51 Communities.· 230 Metering Sites - 192 of which are rates meters to communities.

Water Metering· Metropolitan system was metered from 1900 using Venturi tubes.· Venturi tube upgrades done in the 1980’s. New ones replaced as part of

capital projects.· The system captures 100% of water use.· Meter uptime typically about > 98%.· Meter accuracy is approximately 1%.· 2011 replacement of transmitters and switching to wireless data

transmission to reduce costs.

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VENTURI METER LAYOUT

• Differential producing devices

• Transmitters and data recorders at site send flows to central

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WATER & WASTEWATER METER MAINTENANCE

MWRA staff provide:

Corrective Maintenance when needed, such as:

• Sensor scrubs• Equipment replacement as needed• Communication repairs• Silt removal

Preventative Maintenance, e.g.• Quarterly calibrations• Battery replacement when needed,

(typically 6 Months)• Silt measurements• Venturi sensing line rodding

Independent Checks• Pitot testing of Venturis• Flow testing of wastewater sites

CURRENT WATER SYSTEM RATES ASSESSMENT - QUESTIONS & ISSUES

SHOULD THERE BE A RIGHT-TO-USE/STANDBY FEE

• MWRA has three member communities (Cambridge, Worcester, Leominster) that regularly take no water – but they have the right to take water in an emergency.

• Partial communities take water on an as-needed basis, which can vary significantly from year to year. These communities are assessed just like the full service communities.

• In 2012, MWRA sponsored an American Association of Metropolitan Water Agencies inquiry on rate methodology and stand-by fees. Of 20 survey respondents, 5 had some sort of stand-by fee.

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SHOULD THERE BE A WAY OF CAPTURING THE COST OF OUR CAPACITY INVESTMENTS DUE TO LARGE REDUCTIONS IN MWRA WITHDRAWALS IF A COMMUNITY’S USE SHIFTS TO NEW LOCAL SOURCES, OR REDUCED USE OF LOCAL SOURCES?

• Framingham proposes to develop local sources to supply approximately 3 mgd now met by MWRA.

• Partially supplied MWRA communities may face increased restrictions on local source withdrawals in the future if DEP revises its regulations.

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SHOULD THE EMERGENCY FEE BE REVISITED?

• If a non-member community applies for emergency use of water, and the MWRA Board approves the request, emergency water supply agreements will include a premium charge added to the prevailing rate.

• For water withdrawal periods (no more than 6-months) one through four, the premium charge is now 10% of the MWRA's prevailing rate; premium charges increase to 30% for periods five to seven.

• Should the premium charge be revisited?


SHOULD THE CURRENT RATES ASSESSMENT METHODOLOGY FOR WATER BE REVISITED? CONSIDERATIONS INCLUDE:

• Three-year averaging vs. assessments based on 1 year.

• Potential population component (that could partially address questions raised above).

• Reponses to AWWA inquiry on rate methodology indicated that some utilities have different rates for sole source and non-sole-source (partial user) customers, or rate categories or classes of customers (that could partially address questions raised above).

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How is the Wastewater Rate Revenue Requirement allocated to MWRA

communities?

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SEWER UTILITY ASSESSMENT

Based on the FY2013 budget, on average 54% of the FY2013 sewer assessment was allocated based on flow and strength of flow, and 46% based on population.

Aver-age

Wastewater Flow

25.1%

TSS8.5%BOD

6.8%

Max. Wastewater Flow

13.3%

Popu-lation46.3%

Wastewater

Flow and

Strength53.7%

Popu-la-tion

46.3%

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SEWER UTILITY ASSESSMENT

Community

Boston (BWSC) 29.07% 28.23% $116,347,348 28.27%

FY2013 Assessment

Share of Average Daily Sewer Flow

Population Share

Share of System Assessment

Cambridge 5.43% 4.81% $ 20,768,232 5.05%

Newton 5.40% 3.89% $ 19,917,866 4.84%

Quincy 4.47% 4.22% $ 18,073,247 4.39%

Somerville 3.27% 3.46% $ 13,887,278 3.37%

SYSTEM TOTAL 339.52 (mgd) 2.2M $411,510,599 100%

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WASTEWATER METER OVERVIEW

Wastewater Collection System· 43 Communities.· Number of connections to the MWRA system is 1,978 (1,008 public,

970 private).· 221 Metering Sites, 185 of which are rates meters to communities.

Brief History of Wastewater Metering· Interim Metering System use initiated in December 1991.· First Permanent Metering System completed July 1994.· Used as part of wastewater rates development since 1996.· The last Wastewater Meter Replacement Project was begun in 2003 and

completed in spring 2005.· Meters have run consistently since 2005 and are being replaced

individually when appropriate.

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WASTEWATER METER TYPES

• 134 Marsh McBirney Flo-Dar Radar/velocity Flow meters for most sites

• 53 MGD ADFM – Acoustic Doppler Flow Meters for larger conduits

• 26 Existing meters at local facilities reported to MWRA via RTUs

• 5 Marsh McBirney Flo-Totes for extremely low flow sites

• 3 Flume RTU’s w depth sensors

Note: The Meter types were chosen based on demonstrated superior accuracy during head to head testing at a flow laboratory during vendor selection

Flo-Dar

ADFM

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WEB ACCESS TO WASTEWATER METER DATA

Upon request, MWRA can set up an account so that communities can access current wastewater meter data via the internet

WASTEWATER METERING SYSTEM – COMMUNITY FLOW FORMULAS

DEVELOPMENT/BACKGROUND

• Original vision was to do a benefit/cost analysis to deploy only enough meters to do the job, 85% metered system-wide with some communities being as low as 70%.

• Estimation of non-metered areas was to be done by scaling factors so that flow varied with rainfall.

• Two kinds of non-metered area adjustments were built into the scaling factors – small direct contributions to MWRA pipes and transfers between communities.

• All were field spot checked in 1994 to help develop the original scaling factors.

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COLLECTION BASIN OVERVIEW

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Direct Flow basins


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Net Flow basin


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Unmetered basins (Green circles)

Need Scaling factors


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Unmetered Intercommunity Transfers

(Outlined in green)

Again, need Scaling factor

WASTEWATER METERING SYSTEM – COMMUNITY FLOW FORMULAS

REASONS FOR CHECKING FLOW FORMULAS/UNMETERED AREAS

• The collection basins used in the original community flow formulas remain the same.

• The actual sewer contributions from the unmetered areas may have changed due to I/I changes or changes in use of the structures in the unmetered areas.

• MWRA needs to do a round of updated field readings to confirm proportional flows and scaling factors.

• Considering a field review of 100’s of unmetered sites for all 43 communities:– Presently, only significant changes of which MWRA becomes aware trigger an in-house

review and scaling factor change.– Could begin a multi-year in-house review of all communities that may take a decade to

complete.– Could do aggressive one year testing using contractors.

• Potential impact – May be changes but most will be fairly minor.

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WASTEWATER METERING SYSTEM – REPLACEMENT PROJECT

Update on Meter Condition• System is running reasonably well (30+ ADFMs, 150 Flo-Dars, 20 ADS

Flow Sharks).• Most meters were installed during 2004, making them about 8 years old

now, expected meter life in the harsh sewer environment is 8-10 years.• Starting to see increasing failures but it hasn’t been a big cost issue yet.• Battery life and replacement costs continue to be an issue.• Movement of water meters to Telog Enterprise and wireless transmission is

proceeding, Rosemount transmitter replacement project is 90% complete. Meter Age Solution• We have been carrying $200K for study starting in late FY13 to begin

replacement with proper type, possibly electrifying more sites.• Replacement funds have been put in FY14 and beyond.

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mwra metering system & rates assessment overview

Documents

metropolitan water system

mwra water utility

metered water

mwra communities

communitys total water

water rate revenue requirement

mwras metropolitan water

system total2