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WQPC Rates and Calculation

The Water Quality Protection Charge is calculated based on how much of your property is impervious (does not allow rain to be absorbed into the ground). Properties with small buildings and little development pay less than properties with a lot of developed land.

Image of a residential neighborhood in Montgomery County.

The WQPC varies based on the type of property you own. To view how the charge for your property was calculated, click the appropriate tab to the right.

 

Basis for the Charge

Before calculating how much each property owner was charged, the County first determined how much impervious surface is on a typical property in Montgomery County. This number is called the Equivalent Residential Unit (ERU). Property owners are charged based on how much more or less impervious space they have compared to the ERU.

From the law:

"Equivalent Residential Unit (ERU) is the statistical median of the total horizontal impervious area of developed single family detached residences in the County that serves as the base unit of assessment for the Water Quality Protection Charge. The designated ERU for Montgomery County equals 2,406 square feet of impervious surface."

 

Each tax year the County Council sets how much each ERU will cost. This number is called the Rate. For the 2014 Tax Year, the Rate is $88.40.

1 ERU = 2,406 square feet = $88.40

 

The exact amount of each property's charge is based on two factors:

  • The amount of impervious surface area on the property

  • The type of property owner

 

 

How Was the Amount of Impervious Surface on My Property Determined?

Impervious surface data was gathered from imagery through geographic information systems (GIS) available from Montgomery County and the Maryland-National Capital Park and Planning Commission. Impervious surface area is calculated by totaling the square footage of any surface area that doesn’t allow for rain water to be absorbed.

Image of a backyard in bloom.
Grassy areas, gardens and other landscaped areas are not included in the WQPC. 

The impervious surface area for your property is the total of:

  • Building area
  • Patio area
  • Attached or detached garage building area
  • Walkways
  • Driveway surface area
  • Basketball/tennis courts surface area
  • Private parking lots
  • Other paved areas with concrete or asphalt

 

 

 

 

 

Not included in the total:

  • Pools (Patios and paved areas around the pool are included)
  • Wooden decks
  • Front porches
  • Public sidewalks
  • Agricultural business buildings, such as barns or silos
  • Agricultural driveways

 

 

 

 

 

 

Payment Process

The Water Quality Protection Charge is assessed along with the annual property tax bill on July 1 each year. Payment process and schedules follows the rules and regulations of the Division of Treasury.

Interest on the overdue payment accrues according to the same schedule and at the same rate charged for delinquent real property taxes until the owner has remitted the outstanding payment and interest. An unpaid WQPC is subject to all penalties and remedies that apply to unpaid real property taxes. If the unpaid charge becomes a lien against the property, the lien has the same priority as a lien imposed for nonpayment of real property taxes.

 

Believe your WQPC has been assigned or calculated incorrectly?  File an Appeal

Are you facing financial limitations that would prevent full payment of the WQPC?  Fill out a Hardship Exemption Application

Do you own multiple properties and want them to be calculated as one contiguous unit?  File an Appeal

 

Single-Family Residential Properties

Single-family properties include detached houses and townhomes. They are put into tiers based on how much impervious surface is on the property.

 

Charges for Single-Family Homeowners by Tier
Tiers (Square Feet of Impervious Surface) 2014 Charge
Tier 1 (<=1,000) $29.17
Tier 2 (>1,000 and <=1,410) $44.20
Tier 3 (>1,410 and <=3,412) $88.40
Tier 4 (>3,412 and <=3,810) $132.60
Tier 5 (>3,810 and <=5,815) $176.80
Tier 6 (>5,815 and <=6,215) $221.00
Tier 7 (>6,215) $265.20

 

 

Detached Homes

A detached home is a free-standing residence that does not share a wall with another property.

Detached homeowners are put into the tiers above based on the amount of impervious surface on the property.

 

Graphical image of a house with the impervious areas highlighted.
Key code for the WQPC image above.
 

 

Example:

Mei owns property with a detached house in Montgomery County. Her house has 2,000 square feet of roof surface area. She also has a detached garage with 300 square feet of roof surface area and a driveway of 200 square feet.

The total impervious surface area of Mei’s property is: 2,000 + 300 + 200 = 2,500 square feet

Based on the table above, Mei’s property falls in Tier 3 and she would be charged at the Tier 3 level of $88.40.

 

 

Townhomes

A townhome is a semi-detached property that shares at least one wall with another property. Townhomes are put into the tiers above based on how much impervious surface is on the property.

 

To calculate the impervious surface area for an individual townhome:

  1. Calculate the total shared impervious surface area between all connected properties. This includes building area, communal parking lots, community pools, etc. The total shared surface area is called the “footprint”
  2. Divide the “footprint” by the number of connected properties. The result is your property’s share of the WQPC.
  3. Does your property have any private areas not shared with other townhomes? Private areas caninclude a backyard patio or a basketball court. If so, then the impervious surface area of these private spaces is added to your WQPC calculation.

 

Graphical image of a townhome with the impervious areas highlighted.
Key code for the WQPC image above.

 

Example:

Alissa and Andy own a townhome that is one of four in a row of houses. The total roof surface area of all four townhomes is 4,000 square feet and the communal parking area is 2,000 square feet. Alissa and Andy also have a private garden of 100 square feet and a patio of 400 square feet.

The communal impervious surface area for the row of townhomes (the footprint) is: 4,000 + 2,000 = 6,000 square feet

Divide the “footprint” by the number of properties: 6,000/4 = 1,500 square feet

Alissa and Andy also have the 400 square feet of private patio, making the total impervious surface area of their property: 1,500 + 400 = 1,900 square feet

1,900 square feet falls in Tier 3, and therefore, Alissa and Andy would be charged $88.40.

 

Note: The 100 square feet of garden would not be charged because the garden allows rainwater to pass through the soil. It is not impervious. 

 

 

Image of permeable pavers
Permeable pavers are a great replacement for asphalt or concrete driveways and walkways.  They allow water to absorb through the spaces between the stones.

 

How Can I Reduce My Charge?

Single-family property owners can participate in the WQPC Credit Program and receive a reduction of up to 80% of their charge. By installing stormwater management practices (e.g. rain gardens, dry wells, conservation landscaping), property owners can reduce their charge and help prevent stormwater pollution. An added plus, is that many types of stormwater management techniques beautify property too.

Learn more about the Credit Program and apply.

 

Hardship Exemptions and Appeals

Property owners with financial limitations can apply for the hardship exemption or appeal their charge.

 

 

 

Multi-Family Residential and Condo Properties

A multi-family residential property is defined as where one or more dwelling units share a common entrance from the outside with other dwelling units that are arranged above, below or next to one another in the same building. It is any housing unit that is subject to the condominium regime established under the Maryland Condominium Act.

 

How the WQPC is Calculated for Multi-family Residential Properties and Condo Owners

The total of the impervious area for the entire property is divided equally by the number of owners within the property boundary. If there are 8 condo owners within a property, the total impervious area for the entire property is divided by 8.

The WQPC for each condo owner is their portion of the impervious surface area added to this formula:

Image of the Water Quality Protection Charge calculation.  WQPC = (Square Feet of Impervious Area / ERU) X Rate

 

For the 2014 Tax Year, one ERU = 2,406 square feet and the Rate is $88.40, therefore:

 

Image of the Water Quality Protection Charge calculation.  WQPC = (Square Feet of Impervious Area / 2,406) X $88.40

 

 

What Does the Formula Mean?

The impervious area is the total surface area of your property that does not absorb water, such as the roof, driveway, patio, walkways, etc.  

2,406 square feet is the Equivalent Residential Unit, i.e. the median amount of impervious space on residential properties in the County.

$88.40 is the Rate.  The Rate is set by the County Council each year and for 2014, the Rate was $88.40.

 

Graphical image of a condo building with the impervious areas highlighted.
Key code for the WQPC image above.

 

Example:

Javier owns a condo in a multi-family residential building. There are 6 condos in the building, including Javier’s condo. The building has 4,000 square feet of building area, 2,000 square feet of parking, 2,000 square feet of patio, 500 square feet of basketball court and 200 square feet of driveway.

The total impervious surface area for the building is: 

4,000 + 2,000 + 2,000 + 500 + 200= 8,700 square feet.

8,700 / 6  = 1,450 square feet of impervious space per condo owner

 

To calculate Javier’s charge:

WQPC = (Square Feet of Impervious Area / 2,406) X $88.40

(1,450 / 2,406) X $88.40 = $53.28

 

Javier's Water Quality Protection Charge would be $53.28

 

Image of a rain garden
Rain gardens are a beautiful addition to properties. Water flows to the down-slope garden, which slowly and naturally allows water to drain into the soil.

How Can I Reduce My Charge?

Multi-family residential property owners can participate in the WQPC Credit Program and receive a reduction of up to 60% of their charge. Stormwater management practices can be installed on the grounds, and reduce the charge for each property owner in the condominium regime.

By installing stormwater management practices (e.g. rain gardens, dry wells, conservation landscaping), condominiums can help prevent stormwater pollution, and as an added plus, many types of stormwater management techniques beautify property too.

Learn more about the Credit Program and apply.

 

Hardship Exemptions and Appeals

Property owners with financial limitations can apply for the hardship exemption or appeal their charge.

 

 

 

 

Non-Residential Properties

There are several types of properties that classify as non-residential. 

  • Commercial properties such as office buildings, hotels, retail establishments or industrial properties such as factories and warehouses.
  • Properties owned by homeowner associations, not-for-profit entities such as religious institutions, healthcare facilities, other developed properties devoted to non-governmental charitable and institutional uses, and any government-owned properties subject to the WQPC.

Properties owned by 501(c)(3) organizations are NOT classified as non-residential properties and have a separate WQPC structure.

 

How the Water Quality Protection Charge is Calculated for Non-Residential Properties

The impervious surface area for non-residential properties includes all buildings, parking lots, sidewalks, and any other impermeable installations permanently attached to the property containing those installations.

The WQPC for non-residential property owners is calculated by the following formula:

Image of the Water Quality Protection Charge calculation.  WQPC = (Square Feet of Impervious Area / ERU) X Rate

 

For the 2013 Tax Year, one ERU = 2,406 square feet and the Rate is $88.40, therefore:

Image of the Water Quality Protection Charge calculation.  WQPC = (Square Feet of Impervious Area / 2,406) X $88.40

 

What Does the Formula Mean?

The impervious area is the total surface area of your property that does not absorb water, such as the roof, driveway, patio, walkways, etc. 

2,406 square feet is the Equivalent Residential Unit, i.e. the median amount of impervious space on residential properties in the County.

$88.40 is the Rate.  The Rate is set by the County Council each year and for 2013, the Rate was $88.40.

 

Graphical image of a nonresidential property with the impervious areas highlighted.
Key code for the WQPC image above.

 

Example:

Maria owns a property with a restaurant. The restaurant has 6,000 square feet of roof surface area, 6,000 square feet of parking lot and 2,000 square feet of outdoor paved patio.

The total impervious surface area for Maria's property is:  6,000 + 6,000 + 2,000 = 14,000 square feet

 

To calculate the Maria's charge:

(Impervious Surface Area / 2,406) X $88.40 = The WQPC

(14,000 / 2,406) X $88.40 = $514.38

 

Maria would be charged $514.38

 

Semi-Detached Non-Residential Properties

If your non-residential property is part of a larger building with multiple property owners, such as a storefront in a mixed-use building, the total impervious surface area for your property is calculated by dividing the total shared impervious surface area by the number of property owners and then adding any impervious surface area solely within the boundaries of your property.

 

Example:

Kaleb owns a toy store in a strip of 5 connected commercial properties. The roof surface area for all the businesses is 20,000 square feet. The shared parking lot is 8,000 square feet.

The total impervious surface area for the strip of businesses is   20,000 + 8,000 = 28,000 square feet.

Because Kaleb is one of 5 properties in the strip, he is responsible for 1/5 of the total surface area:   28,000/5 = 5,600 square feet per property owner

 

To calculate Kaleb’s charge:

(Impervious Surface Area / 2,406) X $88.40 = The WQPC

5,600 / 2,406 X $88.40 = $205.75

 

Kaleb would be charged $205.75

 

Image of a green roof.
A green roof slows and absorbs rainwater.  An added benefit is that green roofs also help maintain cooler temperatures indoors in the summer, lowering energy costs.

How Can I Reduce My Charge?

Multi-family residential property owners can participate in the WQPC Credit Program and receive a reduction of up to 60% of their charge. Stormwater management practices can be installed on the grounds, and reduce the charge for each property owner in the condominium regime.

By installing stormwater management practices (e.g. rain gardens, dry wells, conservation landscaping), condominiums can help prevent stormwater pollution, and as an added plus, many types of stormwater management techniques beautify property too.

Learn more about the Credit Program and apply.

 

 

 

 

Agricultural Properties

Agriculture property is defined as a:

  • A property that is used primarily for agriculture, viticulture, aquaculture, silviculture, horticulture, or livestock and equine activities;
  • Temporary or seasonal outdoor activities that do not permanently alter the property's physical appearance and that do not diminish the property's rural character; or
  • Activities that are intrinsically related to the ongoing agricultural enterprise on the property.

Agricultural properties are put into tiers based on the amount of impervious surface area on the property.

 

Charges for Agricultural Properties by Tier
Tiers (Square Feet of Impervious Surface) 2014 Charge
Tier 1 (<=1,000) $29.17
Tier 2 (>1,000 and <=1,410) $44.20
Tier 3 (>1,410 and <=3,412) $88.40
Tier 4 (>3,412 and <=3,810) $132.60
Tier 5 (>3,810 and <=5,815) $176.80
Tier 6 (>5,815 and <=6,215) $221.00
Tier 7 (>6,215) $265.20

 

 

How the Water Quality Protection Charge is Calculated for Agricultural Properties

The impervious surface area charged to agricultural properties is different than what is charged to other properties.

The impervious surface area of an agricultural property is the total of:

  • Building area of the residence

Not included in the total for agricultural properties:

  • Pools 
  • Elevated decks
  • Walkways
  • Public sidewalks
  • Agricultural business buildings such as barns or silos
  • Patio of the residence
  • Detached garage of the residence
  • Driveway of the residence
  • Basketball/tennis courts
  • Other paved areas, such as concrete or asphalt 

 

Graphical image of a agricultural property with the impervious areas highlighted.
Key code for the WQPC image above.

 

Example:

Zach owns an agricultural business with his personal residence also on the property. The house has 3,000 square feet of roof surface area, 1,000 square feet of driveway and a patio around a pool totaling 800 square feet.

Zach’s agricultural business has a barn, work area, silo and shed totaling 5,000 square feet of impervious surface area.

Zach’s property would be charged based on his residence and not the 5,000 square feet of structures used for his business or the 1,800 square feet of patio and driveway.

The total impervious surface area for Zach’s personal residence is 3,000 square feet, which falls in Tier 3.  Zach would be charged $88.40.

Image of a cistern
Cisterns store water after a rain fall.  The water can be used for gardening or farming. 

 

 

How Can I Reduce My Charge?

Agricultural property owners can participate in the WQPC Credit Program and receive a reduction of up to 50% of their charge. By installing stormwater management practices (e.g. rain gardens, dry wells, conservation landscaping), property owners can reduce their charge and help prevent stormwater pollution. An added plus, is that many types of stormwater management techniques beautify property too.

Learn more about the Credit Program and apply.

 

Hardship Exemptions and Appeals

Property owners with financial limitations can apply for the hardship exemption or appeal their charge.

 

 

501(c)(3) Properties

501(c)(3) nonprofit organizations that own properties have a different charge structure than for-profit property owners.

Properties owned by 501(c)(3) organizations are put into tiers based on the amount of impervious surface area on the property. Each tier has a maximum amount that no one in that tier will be charged above.

 

WQPC Charges for 501(c)(3) Properties by Tier
Tiers (Square Feet of Impervious Surface) 2014 Charge
Tier 1 (<=6,910) No more than $132.60
Tier 2 (>6,910 and <=54,455) No more than $795.60
Tier 3  (>54,455) No more than $2,033.20

 

 

How the Water Quality Protection Charge is Calculated for 501(c)(3) Non-profit Organizations

The WQPC for non-profit properties is calculated by the following formula:

Image of the Water Quality Protection Charge calculation.  WQPC = (Square Feet of Impervious Area / ERU) X Rate

 

For the 2013 Tax Year, one ERU = 2,406 square feet and the Rate is $88.40, therefore:

Image of the Water Quality Protection Charge calculation.  WQPC = (Square Feet of Impervious Area / 2,406) X $88.40

 

After calculating the WQPC based on the formula above, compare the resulting number to the Tier Chart. If the WQPC is calculated as more than the maximum for the appropriate Tier, then the property owner is only charged the maximum for that Tier. 

 

What Does the Formula Mean?

The impervious area is the total surface area of your property that does not absorb water, such as the roof, driveway, patio, walkways, etc.  

2,406 square feet is the Equivalent Residential Unit, i.e. the median amount of impervious space on residential properties in the County.

$88.40 is the Rate.  The Rate is set by the County Council each year and for 2013, the Rate was $88.40.

 

 

Image of a stormwater management facility.
Nonprofits can beautify their property and reduce their WQPC by installing stormwater management practices and applying for a credit.

Example:

Paul directs a regional 501(c)(3) organization. To house Paul’s staff, the non-profit owns a property with an office building and parking lot. The property has 6,000 square feet of roof surface area and 10,000 square feet of parking lot area.

The total impervious surface area for the property is: 6,000 + 10,000 = 16,000 square feet.

 

To Calculate Paul’s Non-profit’s Charge:

(Impervious Surface Area / 2,406) X $88.40 = The WQPC

(16,000 / 2,406) X $88.40 = $587.86

With an impervious surface area of 16,000 square feet, this property falls in Tier 2. The calculated amount of charge is less than the maximum for that tier ($795.60) and therefore, Paul’s organization would be charged $587.86.

 

 

Example:

Justine is the executive director of a 501(c)(3) food pantry. The food pantry warehouse has 20,000 square feet of roof surface area and 15,000 square feet of parking lot area.

The total impervious surface area for the property is: 20,000 + 15,000 = 35,000 square feet

 

To Calculate Justine’s Non-profit’s Charge:

(Impervious Surface Area / 2,406) X $88.40 = The WQPC

(35,000 / 2,406) X $88.40 = $1285.95

With an impervious surface area of 35,000 square feet, this property falls in Tier 2. The calculated amount of charge is more than the maximum for that tier ($795.60), and therefore, Justine’s organization would only be charged $795.60.

 

 

Semi-Detached Non-Profit Properties

If your 501(c)(3) property is part of a larger building with multiple property owners, such as an office in a mixed-use building, the total impervious surface area for your property is calculated by dividing the total shared impervious surface area by the number of property owners and then adding any impervious surface area solely within the boundaries of your property. The above 501(c)(3) Tier structure is then applied.

 

Example:

Helene is the executive director of a 501(c)(3) organization that owns an office in a strip of 4 semi-detached commercial properties. The combined impervious roof surface area for the strip of properties is 26,000 square feet. The shared parking lot is 6,500 square feet.

The total impervious surface area for the four properties is: 26,000 + 6,500 = 32,500 square feet.

Because Helene’s non-profit is one of 4 properties in the strip, she is responsible for 1/4 of the total surface area:  32,500/4 = 8,125 square feet

 

To Calculate Helene’s Non-profit’s Charge:

(Impervious Surface Area / 2,406) X $88.40 = The WQPC

(8,125 / 2,406 X $88.40) = $298.52

With an impervious surface area of 8,125 square feet, this property falls in Tier 2. The calculated amount of charge is less than the maximum for that tier ($795.60) and therefore, Helene’s organization would be charged $298.52.

 

Image of permeable pavers
Permeable pavers are a great replacement for asphalt or concrete driveways and walkways.  They allow water to absorb through the spaces between the stones.

How Can I Reduce My Charge?

Agricultural property owners can participate in the WQPC Credit Program and receive a reduction of up to 50% of their charge. By installing stormwater management practices (e.g. rain gardens, dry wells, conservation landscaping), property owners can reduce their charge and help prevent stormwater pollution. An added plus, is that many types of stormwater management techniques beautify property too.

Learn more about the Credit Program and apply.

 

Hardship Exemptions and Appeals

Nonprofit property owners with financial limitations can apply for the hardship exemption or appeal their charge.