A big thanks to those of you who filled out my recent Spokane Riverkeeper Stormwater Quiz. Your participation will help us develop our stormwater education materials in 2011 and beyond. Below you will find the answers to the quiz, and some analysis on those results.
For background, here is the blog post from a few weeks ago where I introduced the Stormwater Quiz.
Listed below is the question and the answers, with the correct answer in red. Next to answers are percentages – those percentage represent the percentages of respondents who chose each of those answers. Here’s a little more on who took this quiz.
43% of respondents work in stormwater management or a related environmental field.
36% are government employees
96% of respondents live in a single family home
Respondents broke down gender wise to 62% male / 38% female.
And age wise, it was all over the board, with 76% being 40-years or older
Now here are the answers:
1) What do you think is the largest source of water pollution in the Spokane River?
A) Agricultural runoff
B) Runoff from forestry and logging
C) Runoff from city streets (68%)
D) Factories and industry (24%)
E) Sanitary sewage system and leaky septic systems (8%)
F) Other
This question is clearly the most debatable on our quiz, but we will make a case that runoff from city streets is the biggest overall source of water pollution in the Spokane River. And, The Environmental Protection Agency (EPA) has determined that stormwater runoff in urban areas is the leading cause of pollution in rivers, lakes, saltwater and other types of surface waters in the country.
2) What is considered stormwater runoff?
A) Rain (4%)
B) Melted snow
C) Debris
D) All of the above (96%)
Answer is D- Stormwater from rain or melted snow flows over driveways, lawns, parking lots, and streets picking up debris chemicals, dirt and other pollutants which flow into storm drains and eventually make their way into our lakes, streams, wetlands, and coastal waters.
3) Which of the following are impacts from stormwater pollution?
A) Cloudy water
B) Algae blooms
C) Fish kills
D) Beach closures
E) All of the above (100%)
Answer is E -Stormwater can contain sediments which make the water cloudy. Stormwater can also contain extra nutrients from yard waste or phosphate that can lead to algae blooms. When algae decomposes it reduces the amount of oxygen available to the fish resulting in fish kills. Harmful bacteria from pet waste and/or malfunctioning septic systems can cause health hazards and ultimately beach closures.
4) In the city of Spokane, how much rain typically falls in one year?
A) 9 Inches (8%)
B) 18 inches (68%)
C) 36 inches (24%)
D) 48 inches
E) 64 inches
The City of Spokane’s website reports that the average annual rainfall is 18.8″ per year.
5) Most storm drains in streets and parking lots of the the Spokane River basin are connected by pipes to
A) A deep dry well or French drain. (8%)
B) A sewage treatment plant. (16%)
C) The nearest creek or stream. (64%)
D) Rain garden or bioswale. (4%)
E) A cistern or underground tank. (8%)
The nearest stream. It is a common misconception that stormwater flows into sanitary sewer systems and is treated before being discharged to the Spokane River.
6) The City of Spokane has how many miles of separate storm sewers?
A) 100 (16%)
B) 200 (16%)
C) 300 (52%)
D) 400 (4%)
E) 500 (12%)
The City of Spokane has just over 300 miles of separate storm sewers that discharge stormwater to infiltration facilities, the Spokane River and Latah Creek at over 100 locations, including many bridges.
7) The City of Spokane has how many miles of combined storm/sanitary systems?
A) 200 (28%)
B) 400 (28%)
C) 600 (28%)
D) 800 (12%)
E) 1,000 (4%)
The City of Spokane has just over 400 miles of combined storm/sanitary systems that carry some stormwater to the City’s treatment plant when it rains. During moderate to heavy rainfall and snowmelt events, a combination of stormwater and untreated sewage can overflow to the Spokane River to prevent overloading the plant.
For a better understanding of types of sewer systems, please enjoy this graphic illustration
http://www.cleanwateratlanta.org/environmentaleducation/SewerSystem.html
8 True (8%) or False (92%): A best management practice to keep rivers clean is to divert stormwater into the river as quickly as possible.
False -Best management practices (BMP’s) are those practices that best promote stormwater control and water quality. Slow flowing water allows sediment more time to settle out of the stormwater and prevents riverbank erosion from occurring, as well as flooding.
9) Copper in water is harmful to fish and other aquatic life. Which of the following is the largest source of copper in stormwater runoff?
A) Fertilizer (20%)
B) Brake linings (48%)
C) Water pipes (28%)
D) Rocks and soils (4%)
E) Paper and plastic litter
Copper deposited on roads by the wearing of brake pads is transported in runoff to streams and rivers according to a news release from Oregon State University. Researchby NOAA Fisheries and others indicate that copper affects the olfactory systems of salmon and trout and makes them more vulnerable to predation. California and Washington have already passed legislation phasing out copper in brake pads.
10) True or False (100%): Nutrients from pet waste are beneficial to our waterbodies.
False - Pet waste can be a major source of bacteria and excess nutrients in local waters. When walking your pet, remember to pick up the waste and dispose of it properly. Flushing pet waste is the best disposal method. Leaving pet waste on the ground increases public health risks by allowing harmful bacteria and nutrients to wash into storm drains and eventually into local water bodies.
11) How many MILLION gallons of used oil are disposed of improperly per year?
A) 1 Million (12%)
B) 70 Million (33%)
C) 100 Million (33%)
D) 180 Million (21%)
Each year in the United States, an estimated 180 million gallons of used oil are disposed of improperly. That’s sixteen times the amount spilled by the Exxon Valdez! Improper disposal of auto fluids includes dripping, spilling, or pouring them onto the ground, directly into waterways, or down storm drains. Check you car for leaks and recycle used motor oil if you change your oil yourself!
12) In Spokane County, what percentage of the land is covered with impervious surfaces (pavement, rooftops) that don’t let rain soak into the ground?
A) 10% (24%)
B) 20% (20%)
C) 30% (44%)
D) 50% (12%)
E) 70% (0%)
About 70%- as figured by local engineer Len Zickler. Here’s Len’s response, “Parking lot acreage is a difficult number to estimate because required off street parking varies by land use. By land use, for single family homes about 10% is in parking. For auto oriented land uses – shopping malls and most commercial – as much as 60% of a site can be in parking and the balance in buildings.
For urban and suburban land uses there there are rules of thumb you can use. First, typically no less than 20% of land area in urban an suburban neighborhoods is consumed by roadways. Additionally, site coverage with buildings ranges between 30% and 90%. The smaller number for low density residential including parking and the larger for industrial and downtown business land uses including required parking.
A good average would be approximately 60% site coverage, as a majority of developed areas in Spokane County are residential. In Spokane approximately 10% of total land area is set aside as open space, parks and critical areas.
So I would conclude, for developed areas, you can add the 20% for roadways, plus 60% for buildings and parking, less 10% for open space, for a total of approximately 70% of impervious surfaces in developed areas.”
13) Recent research shows that water quality declines sharply when impervious cover (roads, driveways, roofs, etc.) in a watershed exceeds:
A) 10% (42%)
B) 20% (25%)
C) 30% (29%)
D) 60% (4%)
E) 75%
The Clean Water Services Healthy Streams Planquotes from various research sources that document impacts occurring when overall impervious cover in a watershed reaches 5-15%. If you answered 10%, you got it right.
14) True (100%) or False: A “bioswale” is a detention pond that acts as a filter for stormwater pollutants.
True - Bioswales are small “ponds” that detain stormwater so that a portion of the water infiltrates into the soil. It also allows sediments to settle out and pollutants to be treated by the vegetation prior to the stormwater discharging to surface waters.
15) Which of the following is NOT a principle of Low Impact Development?
A) Clean up stormwater runoff at a sewage treatment plant (84%)
B) Think of rainwater as a resource, not a waste material (4%)
C) Encourage inflitration to put rainwater into the ground
D) Encourage evaporation and transpiration to put rainwater back into the air (12%)
E) Harvest rainwater in a cistern or rain barrel to use later
Treating rain as a resource, harvesting rain, infiltration and evaporation are all significant aspects of Low Impact Development. The one answer that is not a part of low-impact development is “Clean up stormwater runoff at a sewage treatment plant.” Instead, Low Impact Development aims to treat rain where it falls. Cleaning up stormwater at sewage treatment plants is an expensive proposition and is susceptible to “combined sewer overflows”, which is why the City of Portland is investing $1.4 billion in the “Big Pipe” project.
16) Which of the following is true about the current Municipal Stormwater General Permits issued by Ecology?
A) New developments are required to use Low Impact Development techniques. (32%)
B) Cities may not issue building permits to developments that increase runoff. (8%)
C) Runoff from commercial parking lots is heavily regulated. (4%)
D) Permits must meet strict numeric requirements for pollutants discharged to streams. (28%)
E) Washing your car in the street is specifically exempt from regulation. (28%)
Washing your car in the street is specifically exempt from regulation. Don’t do it. Pollutants from car washing can be deadly to fish, particularly in small streams in the summer when flow volume is low.
