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Stormwater

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1. What is stormwater and why is it a problem?

Stormwater is water from rain and snowmelt. As rain and snow falls to earth in agricultural and undeveloped areas, it is either absorbed or it slowly runs off and dissipates. In urban areas, where rooftops and paved areas prevent the water from being absorbed, problems arise as the runoff collects pollutants and carries them to nearby streams and lakes. Pollutants include gasoline, oil, heavy metals, pesticides, herbicides, fertilizers and bacteria.

Polluted stormwater runoff is a leading cause of impairment to the nearly 40% of surveyed U.S. water bodies which do not meet water quality standards. Left uncontrolled, this water pollution can result in the destruction of fish, wildlife, and aquatic life habitats; a loss in aesthetic value; and threats to public health due to contaminated food, drinking water supplies, and recreational waterways.

2. What kinds of pollutants are found in stormwater?

A pollutant is anything that pollutes the water, or makes it dirty, unhealthy, or unsafe. The most common pollutants in stormwater are sediment, garbage, human and animal feces, motor oil, leaves and yard clippings, fertilizers and pesticides, but the list of pollutants that can make water toxic and unsafe is long. In reality, anything dumped or dropped on the ground or in the gutter may contribute to stormwater pollution as it flows into our creeks, rivers and lakes.

3. Are sewers and storm drains the same thing?

No. They are 2 completely separate drainage systems. Wastewater from sinks, showers, toilets and washing machines travels through the sanitary sewer system to the municipal wastewater treatment plant where solids, nutrients, pathogens and bacteria are removed before being discharged into the Yakima River. On the other hand, the water entering roadside ditches or the storm drain system flows directly to the nearest water body.

4. What can you put down the storm drain?

Only stormwater, runoff from rain or snowmelt, is permitted to be discharged in the storm drain. Yakima County’s illicit discharge ordinance prohibits any water other than stormwater, or any materials, pollutants, or waters containing pollutants other than stormwater, to be put into stormwater facilities. Storm drains discharge directly to surface waters or groundwater without treatment, which means only water that is free of pollutants is permitted to be put into storm drains. 

Yakima County’s Stormwater Code, Chapter 12.10, has more information on what is and isn’t allowed to go into the storm drain.

5. What can residents do to help improve stormwater quality?

There are many things that we can all do on a daily basis to reduce water pollution and otherwise improve stormwater quality. Some of the most important things people can do are very simple, like wise lawn fertilizing and pest treatment practices. You can read more on our Improving Stormwater Quality page.

6. What is the National Pollutant Discharge Elimination System (NPDES) Stormwater Program?

Mandated by Congress under the Clean Water Act, the NPDES Stormwater Program is a comprehensive 2-phased national program for addressing the non-agricultural sources of stormwater discharges that adversely affect the quality of our nation's waters.

The Clean Water Act prohibits anybody from discharging "pollutants" through a "point source" into a "water of the United States" unless they have an NPDES permit. The program uses the NPDES permitting mechanism to require the implementation of controls designed to prevent harmful pollutants found in stormwater runoff from washing into local water bodies. The permit contains limits on what you can discharge, monitoring and reporting requirements, and other provisions to ensure that the discharge does not hurt water quality or people's health.

In essence, the permit translates general requirements of the Clean Water Act into specific provisions tailored to the operations of each person discharging pollutants. In Washington, the Washington State Department of Ecology administers the NPDES program. The Environmental Protection Agency has more information about the program on the NPDES website.

7. What kinds of stormwater discharges are required to have NPDES stormwater permit coverage?

The NPDES stormwater permit regulations cover the following classes of stormwater discharges:

• Operators of Municipal Separate Storm Sewer Systems (MS4s) located in local Urban Growth Areas and "urbanized areas" as delineated by the Bureau of the Census.
• Industrial facilities in any of the 11 categories that discharge to an MS4 or to waters of the United States; all categories of industrial activity (except construction) may certify to a condition of "no exposure" if their industrial materials and operations are not exposed to stormwater, thus eliminating the need to obtain stormwater permit coverage.
• Operators of construction activity that disturbs 1 or more acres of land; construction sites less than 1 acre are covered if part of a larger plan of development.
• Sand and gravel operators.

8. What is a Municipal Separate Storm Sewer System (MS4)?

Any pipe, ditch or gully, or system of pipes, ditches, or gullies, that is owned or operated by a governmental entity and used for collecting and conveying storm water.

9. Which MS4s are regulated by the Eastern Washington Phase II Municipal Stormwater Permit?

Regulated MS4s are those that discharge to surface or ground waters and are designated based on its location within an urbanized area, or otherwise identified by Ecology. MS4s that discharge to groundwater using Underground Injection Control (UIC), also known as drywells, are exempt from the permit. The Department of Ecology has an online map of all Washington state municipal stormwater permit areas.

10. What happens if Yakima County does not comply with its NPDES stormwater discharge permit?

Any violation of the conditions of the Regional NPDES permit would be considered an infringement of the State of Washington Water Pollution Control Law (Chapter 90.48 RCW) and the National Clean Water Act and would be subject to enforcement action by the Washington State Department of Ecology. Any permittee could be fined up to $25,000 per day, per violation, for failure to comply with the conditions of the permit.

11. What is the stormwater utility?

A stormwater utility generates revenue by charging users, property owners, a fee based on the expected amount of stormwater runoff from the property. These fees are then used to implement stormwater management programs in a given jurisdiction.

Yakima County’s stormwater utility was created in 2008. The utility assesses an annual user fee to approximately 10,500 parcels within the service area and generates an operating budget of approximately $500,000 in order to fund stormwater management activities required by the Eastern Washington Phase II Municipal Stormwater permit.

12. Why does Yakima County need a stormwater utility?

The United States EPA issued new stormwater regulations in 1999 that require communities the size of Yakima, Union Gap, Selah, Sunnyside, and urban Yakima County to control water pollution from stormwater runoff. These Phase II communities are required to implement municipal stormwater programs that will reduce stormwater pollution discharges. Washington State Department of Ecology, that administers the NPDES program in Washington, issued the Eastern Washington Phase II Municipal Stormwater Permit on February 16, 2007. The permit requires communities that meet certain criteria to perform 6 control measures, comply with any TMDL processes and monitor the effectiveness of their program. This is known as the “6+2” requirement.

13. What is the stormwater fee used for?

Stormwater utilities in each community provide revenue to pay for operation and maintenance of stormwater infrastructure and permit compliance for stormwater discharges. Yakima County’s stormwater utility pays for the stormwater management program, which manages a wide variety of services and activities. The following is a list of some of the primary services and activities:

• Inspection of construction sites for erosion and sediment control
• Inspection of private stormwater facilities for operation and maintenance
• Review of development plans for surface water management
• Response to citizen inquiries, violation reports, and complaints
• Detection and elimination of prohibited discharges to the storm sewer system
• Storm sewer system mapping
• Public drainage and storm sewer maintenance, repair, and improvement
• Water quality improvement activities (regulatory and local needs based)
• Water quality improvement projects
• Total Maximum Daily Loads (TMDLs)
• Stormwater facility retrofits
• Public outreach and education activities
• Recordkeeping and report preparation

14. How will the stormwater management program benefit taxpayers, homeowners, etc.?

Based upon the level and extent of services being funded, the Stormwater Management Program includes a wide variety of services and activities. You can find a list of the primary services and activities online.

15. How are the regional stormwater utility service areas determined?

The utility service areas for the cities of Yakima and Sunnyside are the city limits. Selah and Union Gap currently do not have a stormwater utility. For urban Yakima County, the utility service area is the larger of either the Urban Growth Area, or the U.S. Census Bureau 2000 Census definition of “urban” based on population density. The County utility service area mirrors the extent of the regulated municipal storm sewer system defined in the Washington Department of Ecology Eastern Washington Phase II Municipal Stormwater Permit. A map of the Yakima County Stormwater Utility boundary is available online. 

16. How is the stormwater fee calculated?

First, an Equivalent Residential Unit (ERU) is calculated. In Yakima County, the City of Yakima and City of Union Gap, this was done by statistically sampling residential properties and averaging the amount of impervious surface using aerial photography and the County Geographical Information System (GIS). Based on this analysis, one ERU is 3,600 square feet.

Next, the property or land area of all developed parcels in the County are classified into one of the following general classes based on zoning land use categories: Urban Residential; Urban Commercial/Industrial (including government, military, schools, churches, etc); Urban Agricultural; and Exempt.

Assignment of ERU to residential parcels varies between the regional municipalities. For urban commercial, industrial, institutional, and governmental parcels, the number of urban ERUs is determined by dividing the amount of impervious surface (in feet squared) on the parcel by 3,600 square feet. ERUs for urban agricultural parcels are based on parcel size, a complete listing of agricultural parcels is available online.

17. What is an impervious surface?

Impervious surface means those disturbed or hard surfaced areas that either prevent or impede the natural entry of water into the soil. Rooftops, buildings, streets, parking lots, sidewalks, asphalt, concrete, other paving, driveways, patios, artificial turf and storage areas are all examples of impervious surfaces. These improvements effect natural infiltration, creates more runoff, increases the rate of runoff and alters runoff patterns of stormwater that drains from an area.

18. Is the utility fee just another tax?

No. The stormwater utility fee is a user fee. Although the fee is a cost to property owners, it is not a tax on the value of the property. It is assessed depending on the amount of impervious surface which is related to the amount of stormwater runoff. The stormwater utility fee is collected to finance current costs associated with stormwater management in the urban areas of Yakima County. This is similar to fees collected to handle and manage solid waste.

19. No water runs off my property. Why am I being charged a stormwater fee?

Almost every property discharges some stormwater into the public drainage systems, even if it is not noticeable to you. Many properties generally discharge runoff during snow melt when ground conditions are frozen. If absolutely no stormwater drains from your property, even during severe storms or periods of frozen ground, you may still be served by the existence of a regional stormwater program.

Public properties also discharge to the public drainage system, thus stormwater from the roads you drive on, parks you recreate in, and emergency service facilities you rely on contribute to stormwater pollution. Keep in mind that a lot of stormwater does run off from other properties. Properly controlling that stormwater runoff is a very real service to you and other property owners.

The pollutants in stormwater go to area creeks, streams, and lakes and affect the health of people, fish, wildlife and other natural resources that depend on those habitats. That same water is pumped for irrigation on crops and for use in drinking water. Stormwater quality affects everyone, even though the sources are generally a result of urbanization.

20. What is meant by a "larger common plan of development or sale?"

A "larger common plan of development or sale” is a contiguous area where multiple separate and distinct construction activities may be taking place at different times on different schedules under 1 plan. For example, if a developer buys a 20-acre lot and builds roads, installs pipes, and runs electricity with the intention of constructing homes or other structures sometime in the future, this is considered a common plan of development or sale. If the land is parceled off or sold, and construction occurs on plots that are less than 1 acre by separate, independent builders, this activity would still be subject to stormwater permitting requirements if the smaller plots were included on the original site plan.