The State of Our Streams: 2010
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A Report on Water Quality to the Citizens of Durham The State of Our Streams: 2010 Stormwater Services is making lots of changes because of new State requirements, like the recently adopted Falls and Jordan Lake Rules. Help Stop Stormwater Pollution! Rules directed at reducing the amount of algae in Call 560-SWIM to report anything in creeks or Falls Lake were adopted by the State in storm drains that is not water! November 2010. They became effective in January 2011. Jordan Lake rules have been in place since 2009. Because of these rules, new shopping centers, office buildings, neighborhoods, and other construction will have to take more nutrients out of stormwater that runs off their property. This way stormwater from hard surfaces such as driveways, parking lots, and roof tops continues to be treated far into the future. This will affect whoever has to maintain the stormwater treatment controls, such as homeowners associations and business property managers. The new stormwater rules cover not only new buildings, but also land that is already developed. Man-made Stormwater Wetland at Hillandale Golf This includes historic buildings, schools, older Course to treat polluted water neighborhoods, business districts, and roads. Treating runoff will be challenging in these boxes filter stormwater runoff from public neighborhoods because of a lack of space, costs, roads. and the required maintenance. One way the City is trying to overcome this challenge is through a You can also expect other changes to City grant funded program that designs and installs stormwater programs and reports as the State rain gardens. This is done in partnership with changes how it implements the Clean Water Act. homeowners living south and west of the This will lead to changes in water quality Durham Freeway. (For more information or to monitoring and the water quality index scores volunteer, contact Robert Louque at 560-4326.) provided in the State of Our Streams report. The Another new method the City is using to treat future is always changing and so are we at runoff is street side filter boxes. In several recent Stormwater Services. projects, including the upgrade to City Hall Plaza, City of Durham Stormwater Services—(919) 560-4326 www.DurhamNC.gov/stormwater Design/Plan Review—Drainage/Flooding Concerns—Floodplain Information The State of Our Streams: 2010 Explanation of Watershed Attachments Watershed Information: This section briefly describes the watershed such as location, In order to provide further information to landuse, or any other notable characteristics of residents, a water quality report is available for the watershed. These can all influence water each of the major watersheds in the City of quality and are important to know. Durham. Sections included in each report are as follows: Pollution Sources: Stormwater Services staff conduct investigations when City staff or Durham Water Quality Index (WQI): Federal regulations residents report a water quality concern. They require the City of Durham to monitor water also conduct investigations when routine tests quality in local streams. Stormwater Services indicate a problem. Investigations help find staff collects water samples from streams anything other than rain water getting into the throughout the city. These samples are then storm drain system, streams, or lakes. These are tested for biochemical oxygen demand, nutrients known as illicit discharges, and are a major (nitrogen/phosphorus), bacteria, clarity, and source of pollution in urban areas. Examples of metals. These tests allow City and State staff to illicit discharges include: pouring oil into storm determine potential risks to people, drinking drains, disposing of pet wastes in storm drains, water supplies, and wildlife. and leaking or overflowing sanitary sewer pipes. Pollutions sources found during investigations The results from these chemical tests are are included in each watershed’s report. combined into one score to provide a broad picture of the health of our streams. The WQI is The City has limited staff and resources to provided for each monitoring site where enough improve water quality. Therefore, it is essential chemical test results are available. that residents become involved and provide extra eyes, ears, and noses to help find and get rid of The WQI can be thought of as a school test grade, sources of pollution. Call 560-SWIM to report numbers close to 100 are an “A” and numbers water pollution. less than 60 are an “F”. Looking at this grade from year to year can show how water quality is changing in area streams. All urban streams usually fail to meet at least one federal or state water quality standard. However, the water quality index allows residents and Stormwater Services to locate areas with the most serious pollution issues. These areas can be targeted for improvement plans or investigations to find pollution sources. In 2010, Stormwater Services Staff tested water quality at 48 spots in local streams. Sanitary Sewer Crossing: Ellerbe Creek at Stadium Dr City of Durham Stormwater Services page 2 of 3 The State of Our Streams: 2010 At the end of individual reports, a table is provided that indicates watershed health in terms of: Clarity: Dirt washed into streams can cause the water to appear cloudy or muddy. One way to at 919-560-7800. measure this is called turbidity. Turbidity measures how bits of dirt scatter light in the Aquatic Life: In addition to chemical tests, water. Turbidity is tested on site in streams. Stormwater Services staff also collects aquatic There is a North Carolina water quality standard life to learn about water quality. Aquatic of 50 Nephelometric Turbidity Units (NTU) for organisms, or benthic macroinvertebrates, live in turbidity. Ratings are as follows: the water on roots, under rocks, and under Good: meets state standard leaves. Since these organisms are exposed to Poor: does not meet standard pollution in the stream, the variety found by staff is a good indication of water quality. When Recreation: Many people like to know that their organisms that are sensitive to pollution are streams are safe for fishing and swimming. These present and there are fewer pollution tolerant uses are impacted by bacteria and viruses. When organisms, the overall rating increases. The found, fecal coliform bacteria suggest there is aquatic life rating is often a better indicator of raw sewage (poop!) in a stream. This is a concern overall water quality than the water quality because sewage contains viruses, bacteria, and index. other pathogens that make people and pets sick. Fecal coliform bacteria is measured regularly by Reference Site: A common method to compare Stormwater Services. Fecal coliform bacteria are water quality of impacted urban streams is using measured in water samples collected from information from an unpolluted or reference streams and have two North Carolina water stream. A reference stream can be defined as a quality standards. They are a geometric mean of relatively undisturbed stream that supports the 200 colony forming units (cfu) per 100 milliliters intended use of water for recreation or as water (mL) and the number of exceedances of 400 supply. A reference site typically has good water cfu/100mL. Ratings are as follows: quality that either meets or exceeds state standards. Stormwater Services maintains three Good: meets both state standards such reference sites,- Flat River, Little River, and Fair: meets the geometric mean standard New Hope Creek. Poor: does not meet either standard Stormwater Services staff receives many questions about harmful bacteria. Because of this, the State of Our Streams report provides the recreation indicator as a service to residents of What can I do to protect water quality? Durham. Stormwater Services cannot issue public (Tip #1) health warnings regarding the safe use of area Keep trees and shrubs growing along streams and rivers. If you have any questions or stream banks as buffer zones to filter soil concerns about area streams or rivers please and pollution from entering waterways. contact the Durham County Health Department City of Durham Stormwater Services page 3 of 3 This Page intentionally left blank The State of Our Streams: 2010 City of Durham 2010 Water Quality Index, City of Durham: 8080 some pollution, and light orange through dark orange indicates increasing pollution. This section is an attachment to the State of Our Results for fecal coliform bacteria are Streams 2010 Report prepared by the City of summarized on page 4. A similar color range Durham Stormwater Services. The entire report is shows how polluted each area is with bacteria. available at: http://www.durhamnc.gov/departments/works/ Pollution sources stormwater_water_quality.cfm. Stormwater Services staff found 138 pollution sources during investigations from October 2009- The City of Durham is situated along a high point September 2010. A variety of pollution sources between two major river basins, the Cape Fear were identified and are shown below. and the Neuse. Waters from the south and west of the Durham Freeway (NC 147) generally flow Number of Water Quality Investigations to Jordan Lake, the Cape Fear River, and finally Identifying Pollutant Sources, 2004—2010 the Cape Fear Estuary. Waters north and east of the Durham Freeway flow to Falls Lake, to the Neuse River, and ultimately to Albemarle-Pamlico Sound. Stirrup Iron Creek, also east of NC 147 flows into Crabtree Creek and then to the Neuse River. Colored areas in the map (page 2) around a stream show the stream's watershed. A watershed is the land area that drains water and the pollution it carries to a stream. Most Durham streams originate within the city. Sources and Types of Pollution Found Because of this, activities in the City play an in 2010 important role in these streams water quality. Urban areas and industrial activities can lower water quality if not managed properly.