WQPC Rates & 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.
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.
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 1st 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?
- Are you facing financial limitations that would prevent full payment of the WQPC?
- Do you own multiple properties and want them to be calculated as one contiguous unit?
- Residential and Agricultural Properties
- Multi-Family and Non-Residential Properties
- Nonprofit Properties
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.
Each tax year the County Council sets how much each ERU will cost. This number is called the Rate. For this tax year (2020), the Rate is $119.50.
1 ERU = 2,406 square feet = $119.50
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
Choose your property type below to see how your charge was calculated:
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.
| Tiers (Sq. Ft. of Impervious Surface) | Charge Amount per Tax Year |
|---|---|
| Tier 1 (<=1,000) | $39.83 |
| Tier 2 ( >1,000 and <=1,410) | $59.75 |
| Tier 3 (>1,410 and <=3,412) | $119.50 |
| Tier 4 (>3,412 and <=3,810) | $179.25 |
| Tier 5 (>3,810 and <=5,815) | $239.00 |
| Tier 6 (>5,815 and <=6,215) | $298.75 |
| Tier 7 (>6,215) | $358.50 |
Most residential property owners will pay $119.50 or less
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.
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 $119.50.
Townhomes
A townhome is a semi-detached property that shares at least one wall with another property. Townhomes are put into the tiers based on how much impervious surface is on the property. (See the tier chart above)
To calculate the impervious surface area for an individual townhome:
- 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”
- Divide the “footprint” by the number of connected properties. The result is your property’s share of the WQPC.
- Does your property have any private areas not shared with other townhomes? Private areas can include a backyard patio or a basketball court. If so, then the impervious surface area of these private spaces is added to your WQPC calculation.
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 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 $119.50.
Reduce Your 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.
Additional Charge Reduction Programs:
Permeable pavers are a great replacement for asphalt or concrete driveways and walkways.
They allow water to absorb through the spaces between the stones.
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 is the WQPC 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. (For example, 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:
For this tax year, one ERU = 2,406 square feet and the Rate is $119.50, therefore:
$119.50
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.
- $119.50 is the Rate. The Rate is set by the County Council each year and for this tax year, the Rate is $119.50.
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 = (1,450 / 2,406) X $119.50 = $70.53
Reduce Your Charge
Multi-family residential property owners can participate in the WQPC Credit Program and receive a reduction of up to 60% for complete onsite treatement of stormwater or up to 80% of their charge for complete onsite treatement of stormwater using environmental site design technology. Additional credits can be achieved for offsite stormwater treatment. 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.
Additional Charge Reduction Programs:
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.
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 is the WQPC 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:
For this tax year, one ERU = 2,406 square feet and the Rate is $119.50, therefore:
$119.50
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.
- $119.50 is the Rate. The Rate is set by the County Council each year and for this year, the Rate was $119.50.
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:
WQPC = (14,000 / 2,406) X $119.50 = $695.34
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 calculation is slightly different.
To calculate the charge for semi-detached non-residential properties:
Step 1: Divide the total shared impervious surface area by the number of property owners
Step 2: Add to the number from step 1 the total impervious space area solely within the boundaries of your property
Step 3: Take the number from Step 2 and import it into the formula below.
$119.50
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:
WQPC = (5,600 / 2,406) X $119.50 = $278.14
Reduce Your Charge
Non-residential property owners can participate in the WQPC Credit Program and receive a reduction of up to 60% for complete onsite treatement of stormwater or up to 80% of their charge for complete onsite treatement of stormwater using environmental site design technology. Additional credits can be achieved for offsite stormwater treatment. 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.
Additional Charge Reduction Programs:
A green roof slows and absorbs rainwater.Green roofs also help maintain cooler temperatures indoors in the summer, lowering energy costs.
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.
| Tiers (Sq. Ft. of Impervious Surface) | Charge Amount per Tax Year |
|---|---|
| Tier 1 (<=1,000) | $39.83 |
| Tier 2 ( >1,000 and <=1,410) | $59.75 |
| Tier 3 (>1,410 and <=3,412) | $119.50 |
| Tier 4 (>3,412 and <=3,810) | $179.25 |
| Tier 5 (>3,810 and <=5,815) | $239.00 |
| Tier 6 (>5,815 and <=6,215) | $298.75 |
| Tier 7 (>6,215) | $358.50 |
How is the WQPC 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 only based on 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
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 agricultural structures used for his business or the 1,800 square feet of patio and driveway.
The total impervious surface area for the residence: 3,000 square feet Zach's property falls in Tier 3, and therefore, he would be charged $119.50.
Reduce Your Charge
Agricultural 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.
Additional Charge Reduction Programs:
Cisterns store water after a rain fall. The water can be used for gardening or farming.
501(c)(3) Nonprofit 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.
| Tiers (Sq. Ft. of Impervious Surface) | Charge Amount per Tax Year |
|---|---|
| Tier 1 (<=6,910) | No more than $179.25 |
| Tier 2 ( >6,910 and <=54,455) | No more than $1,075.50 |
| Tier 3 (>54,455) | No more than $2,748.50 |
How is the WQPC Calculated for 501(c)(3) Nonprofit Organizations?
The WQPC for nonprofit properties is calculated by the following formula:
For this tax year, one ERU = 2,406 square feet and the Rate is $119.50, therefore:
$119.50
After calculating the WQPC based on the formula, compare the resulting number to the Tier Chart above. 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.
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.
- $119.50 is the Rate. The Rate is set by the County Council each year.
Examples
Example #1:
Paul directs a regional 501(c)(3) organization. To house Paul’s staff, the nonprofit 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 Nonprofit’s Charge:
Step 1: Determine the charge before the nonprofit tier reduction
(16,000 / 2,406) X $119.50 = $794.68
Step 2: Determine which tier Paul's nonprofit belongs in.
With 16,000 sq. ft., Paul's property falls in Tier 2
Step 3: Compare the max charge for the tier with the amount calculated in Step 1.
The calculated amount of charge is less than the maximum for that tier ($1,075.50) and therefore, Paul’s organization would be charged $794.68.
Example #2:
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 Nonprofit’s Charge:
Step 1: Determine the charge before the nonprofit tier reduction
(35,000 / 2,406) X $119.50 = $1,738.36
Step 2: Determine which tier Paul's nonprofit belongs in.
With 35,000 sq. ft., Justine's property falls in Tier 2
Step 3: Compare the max charge for the tier with the amount calculated in Step 1.
The calculated amount of charge is more than the maximum for that tier ($1,075.50) and therefore, Justine's organization would be charged $1,075.50.
Semi-Detached Nonprofit 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 Nonprofit’s Charge:
Step 1: Determine the charge before the nonprofit tier reduction
(8,125 / 2,406) X $119.50 = $403.55
Step 2: Determine which tier Helene's nonprofit belongs in.
With 8,125 sq. ft., Helene's property falls in Tier 2
Step 3: Compare the max charge for the tier with the amount calculated in Step 1.
The calculated amount of charge is less than the maximum for that tier ($1,075.50) and therefore, Helene's organization would be charged $403.55.
Reduce Your Charge
Non-residential property owners can participate in the WQPC Credit Program and receive a reduction of up to 60% for complete onsite treatement of stormwater or up to 80% of their charge for complete onsite treatement of stormwater using environmental site design technology. Additional credits can be achieved for offsite stormwater treatment. 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.
Additional Charge Reduction Programs:
Permeable pavers are a great replacement for asphalt or concrete driveways and walkways. They allow water to absorb through the spaces between the stones into a stone subsurface drainage system that has a minimum depth of 12 inches. Stormwater drains through the pavement, is captured in the stone layer, and infiltrates into the surrounding soils.