This is one of Ann Arbor's more significant trees. Some readers will undoubtedly recognize it and will know its location, type, and age – which they're invited to leave in the comment section.

This month’s report is also an invitation to all readers to participate in the development of Ann Arbor’s first comprehensive Urban Forest Management Plan. A public workshop to help kick off the planning effort is being held on June 1, 2010 from 7-9 p.m. at Forsythe Middle School, 1655 Newport Road.

This spring has been exceptional with both beautiful weather and ample rain. The trees seemed to have noticed, with their early bud break in April and full canopies by mid-May. While we worried for those tender emerging leaves when the temperature dipped below freezing, the trees handled the dips in temperatures just fine and are now flourishing.

That’s good news because the city receives exceptional benefits from our trees. A recent analysis of the publicly managed trees (i.e., trees along streets and mowed areas of parks) estimated that they provide $4.6 million in benefits each year. When you factor in the cost for management, the city receives $2.68 in benefits for every $1 it spends on the municipal forestry program. We think that’s a pretty good rate of return.

What are these benefits and how were they calculated?

How Tree Benefits Are Calculated

In 2009, the city contracted with the Davey Resource Group to conduct a comprehensive inventory of street trees and park trees in mowed areas. Some Ann Arbor residents probably remember seeing the survey work in progress.

Using the data from this newly completed tree inventory, the Davey Resource Group then calculated the values and benefits of the city’s public trees. The city’s website summarizes them on a page titled “Benefits of Urban Forests.” The calculations were done using i-Tree, a suite of peer-reviewed software programs developed by the USDA Forest Service.

The Benefits of City Trees

The city’s public trees conserve and reduce energy, reduce carbon dioxide levels, improve air quality, mitigate stormwater runoff, and provide other benefits associated with aesthetics, increased property values, and quality of life. It’s great to be able to describe these benefits in words but even more powerful when we can show you in numbers. Here are some of the numbers:

• Public trees reduce energy and natural gas use in Ann Arbor from shading and climate effects equal to 3,408 MWh and 1,260,313 therms, for a total savings valued at approximately $2,252,055, with a citywide average of $47.55 per public tree.
• Ann Arbor’s public trees reduce atmospheric CO2 by a net of 7,851 tons per year, valued at $52,450 for an average net benefit per tree of $1.11.
• The net air quality improvement from the removal and avoidance of air pollutants is valued at $395,569 per year, with an average net benefit per tree of $8.35.
• Ann Arbor’s public trees intercept 65.0 million gallons of stormwater annually. The total value of this benefit to the city is $519,895 per year, for an average value of $10.98 per inventoried tree.
• The estimated total annual benefit associated with increased property values, aesthetics, and other less tangible improvements is $1,368,302 per year, for an average of $28.89 per inventoried tree.

You may already be familiar with many of these benefits – at least in general terms – but having a quantifiable figure attached to each of them begins to demonstrate the value of our city’s “green infrastructure.” These trees are an asset that is owned and managed by the city. The city is beginning to develop an urban forest plan to ensure that this resource is sustainable and continues to provide benefits into the future.

Trees are a defining characteristic of Ann Arbor (Tree Town) that make the city a desirable place to visit, work, do business, and live. This month’s indicator report focuses on Ann Arbor’s urban forest, and the metrics used to measure its quality.

Urban Forest Environmental Indicators

The State of Our Environment report includes three indicators for Ann Arbor’s urban forest: Tree Diversity, Size Class, and Urban Tree Canopy.

Indicator: Tree Diversity

Tree Diversity Indicator

Let’s start with tree diversity. The indicator is rated as poor (red) because of the dominance of Maple (Acer) species, and the indicator is improving (upward arrow) because of focused efforts to increase species diversity through new plantings.

The recently completed comprehensive street and park tree inventory cataloged over 40,000 street trees, 6,600 park trees in mowed areas and 8,800 potential planting sites. According to the inventory, Maple (Acer) species makes up nearly 40% of Ann Arbor’s urban forest.

The tree inventory did not account for trees on private property or in city-owned natural areas.

(Image links to higher resolution chart.)

Diversity plays an important role in the long-term stability of an ecosystem. When an area has a high diversity of tree species, it is less likely to suffer catastrophic loss from diseases or pests. For example, consider the impact the Emerald Ash Borer (EAB) had on Ann Arbor ash trees. The Emerald Ash Borer (Agrilus planipennis), an exotic wood-boring beetle discovered in the area in the summer of 2003, has killed more than 10 million trees in southeast Michigan.

Prior to the EAB infestation in 2002, ash trees comprised 17% of Ann Arbor’s tree population. The EAB infestation resulted in the emergency removal of 10,000 ash trees that were planted along public sidewalks and in parks. Planting a diversity of hearty tree species throughout Ann Arbor neighborhoods can reduce the vulnerability of the urban forest to species-specific pests. A good rule of thumb is that no more than 10% of a city’s tree population should consist of one species.

The city of Ann Arbor is increasing urban forest tree diversity through replanting efforts. More than 4,000 trees have been planted since 2004. In fall 2010, an additional 705 trees representing 28 different genera were planted, with more plantings planned in the spring. An important component of the replanting strategy is a focus on diversifying the tree population by planting non-maple species.

Indicator: Size Class

Size Class Indicator

Moving on to the urban forest size class indicator, the news is much better. We rated the indicator as good (green) and improving (upward arrow). It’s hard to tell a tree’s age without cutting it down to count its rings or taking core samples, which damages the tree.

Instead, we use the diameter at breast height (DBH) as a predictor of tree age. Young trees have small DBH measurements and as trees mature, DBH increases. Ann Arbor has a healthy mixture of young, middle, and old individuals and the tree inventory shows a similarly healthy mix of trees.

(Image links to higher resolution bar chart.)

In the same way that high species diversity reduces a forest’s vulnerability to species-specific pests and diseases, a diverse age structure reduces the possibility that all the trees in the forest will begin to die at the same time. A healthy mixture of young, medium, and old trees provides a nearly constant turnover of generations over time as new trees replace the old. In addition, trees of different sizes provide more complex habitat for wildlife and can support a greater number of species.

An ideal tree population’s age distribution is skewed toward younger trees because it ensures there will be a continuous flow of benefits as mature trees begin to decline.

Indicator: Urban Tree Canopy

UTC Indicator

The last Urban Forest Indicator is the Urban Tree Canopy (UTC). We rated the indicator as fair (yellow) and stable (flat arrow). This is a new indicator based on very recent and very accurate remote sensing data.

While the tree inventory only looked at publicly managed trees, the canopy cover analysis measures the canopy of the entire city – the cumulative cover of all public- and privately-owned trees. The analysis is based on 2009 “leaf-on” aerial imagery. We rated this indicator as fair (yellow) because, with 33% canopy, the city of Ann Arbor has average or above-average tree canopy cover compared with other small and medium-sized communities in the United States (see Existing UTC Chart below).

With this percent canopy cover, Ann Arbor should focus on maintaining and preserving tree canopy to sustain functional benefits while also targeting areas for improvement. We rated the indicator as stable (flat arrow) because the canopy cover of newly planted trees does not (yet) replace the canopy cover we lose when a large mature shade tree dies.

(Image links to higher resolution chart.)

The UTC analysis provides a rich dataset that can be used with other city GIS layers. For example, this chart shows the canopy cover by creekshed and the potential urban tree canopy within each watershed.

                                        Total   Total
                      Exist.  Exist.    Poss.   Poss.
               Total   UTC     UTC      UTC     UTC
Creekshed      Acres  Acres     %       Acres    %   

Huron River 	4,213 	1,646 	39.1 	1,454 	34.5
Fleming Creek 	642 	184 	28.7 	311 	48.4
Traver Creek 	1,578 	508 	32.2 	774 	49.0
Honey Creek 	815 	335 	41.1 	296 	36.4
Millers Creek 	1,415 	460 	32.5 	669 	47.3
Allen Creek 	3,340 	1,151 	34.5 	1,287 	38.5
Mallets Creek 	5,087 	1,427 	28.0 	2,451 	48.2
Swift Run 	1,174 	303 	25.8 	667 	56.8

-

Using these new data, GIS tools, and input from the public engagement process, we will develop an Urban Forest Management Plan that maximizes the benefits of the urban forest while meeting the needs and values of the community.

Paths to Contribution

Are you interested in trees? Do you want to influence how trees in the city of Ann Arbor are managed?

Participate in the Process: Urban Forest Management Plan

Join us on Tuesday, June 1 from 7-9 p.m. at Forsythe Middle School, 1655 Newport Road, to learn about Ann Arbor’s urban forest and to share your ideas about the tree planting, tree trimming, tree removals and the development of the city’s first urban forest management plan. Go to the urban forestry website for more information.

Educate Yourself

Learn about the trees in your neighborhood. The city’s data catalog includes a Google Earth file of every tree in our inventory. [.kmz file of Ann Arbor Google Earth Tree Data – note that this is a very large file]

Get Your Hands Dirty

Help plant the city’s trees. More information on that is available on the city’s website:  www.a2gov.org/trees

Volunteer at events sponsored by the city’s Natural Area Preservation Program and Adopt-a-Park program that are helping to improve the urban forest.

Maintain Your Private Trees

• Ensure that newly planted trees are watered weekly, if we receive no rain.
• Avoid the untimely death of young trees from weed whip and lawn mower damage by mulching around your trees (be sure to keep mulch away from the trunk).
• Prune young trees to improve their structure and prune out dead, diseased or dying limbs in mature trees. Hire a certified arborist if the tree is too large to safely prune it yourself.

About the authors: Kerry Gray is the urban forestry and natural resources planning coordinator; Matthew Naud is the city’s environmental coordinator; and Adrienne Marino is environmental programs assistant. They’re all staff with the city of Ann Arbor.

The State of Our Environment Report is developed by the city’s environmental commission and designed as a citizen’s reference tool on environmental issues and as an atlas of the management strategies underway that are intended to conserve and protect our environment. The newest version of the report is organized around 10 environmental goals developed by the environmental commission and adopted by the city council in 2007.

Phosphorus takes its place in the periodic table of elements with atomic number 15. Too much P is not good for the Huron River.

This installment focuses on phosphorus levels in our creeks and river. Adrienne Marino is a recent graduate of the University of Michigan School of Natural Resources and Environment and is an Environmental Programs Assistant with the city of Ann Arbor. Matthew Naud is the Environmental Coordinator at the city of Ann Arbor and can be reached at mnaud@a2gov.org.  Elizabeth Riggs with the Huron River Watershed Council and Molly Wade with the city of Ann Arbor provided additional input on the regulatory issues.

All installments of the series are available here: Environmental Indicator Series.

April showers will surely give way to May flowers and the start of lawn care season in southeast Michigan. As you tend to your lawn this spring and summer, you should know that your choices regarding lawn maintenance – especially fertilizer application – have large and measurable effects on the health of the Huron River and on the natural and human communities who depend on it.

How do we know this? The city of Ann Arbor’s ordinance regulating phosphorus-based lawn fertilizers took effect at the beginning of 2007. And sampling of Huron River phosphorus levels by University of Michigan scientists shows significant decreases in total phosphorus levels in 2008 and 2009. Huron River Watershed Council sampling of the creeksheds support these findings.

Why Measure Phosphorus?

Applications of lawn fertilizer by residents are an example of non-point sources of phosphorus [chemical symbol P]. That’s different from a single-point source of phosphorus like the city’s waste-water treatment plant. This month’s installment on environmental indicators discusses Total Phosphorus Reductions in the Huron River and chronicles a community-wide effort among residents, non-profits, local governments, and businesses to limit non-point sources of phosphorus to the Huron River.

The city of Ann Arbor is interested in monitoring phosphorus on the Huron River for two basic reasons. First, it’s because the city understands the possible negative environmental impact of excess phosphorus in the river. Second, the amount of phosphorus in the Huron has drawn the attention of the federal government.

So collecting phosphorus data provides information needed to assess progress toward federally mandated phosphorus reduction requirements. Communities in the Middle Huron watershed – which encompasses the land that drains into Ford and Belleville lakes – are under a federal  TMDL requirement for phosphorus.

What’s a TMDL?

A TMDL, or Total Maximum Daily Load, is established by the state and quantifies the amount of a pollutant a water body can accept, or assimilate, without violating water quality standards. [We pronounce TMDL like you would "timdle," if that word existed.] This load is calculated based on point source loading, plus non-point source loading, plus a margin of safety.

The TMDL for Ford and Belleville lakes specifies the amount of phosphorus the lakes can assimilate and still meet protected uses – e.g., not stimulate algal blooms, which are rapid population increases of algae in an aquatic system. TMDLs are required for water bodies that are not attaining standards established by the federal Clean Water Act (CWA). The Michigan CWA program is administered by the Department of Natural Resources and Environment [formerly Michigan Department of Environmental Quality].

One algal bloom on Ford Lake in 1991 was so severe that a hazardous materials team was called in to investigate what residents thought was a “green paint spill.” More details on why phosphorus is a problem can be found at the end of this article.

Phosphorus is not inherently a pollutant – it’s an essential nutrient for plant growth. But in excess, it wreaks havoc on aquatic ecosystems, often contributing to nuisance plant growth and algal blooms.

Excess phosphorus enters the Huron River from both point and non-point sources. The main point source under our control is the Ann Arbor wastewater treatment plant. The plant accounts for 43% of Ann Arbor’s cumulative phosphorus input into the Huron River. Point sources have been regulated under the Clean Water Act since the 1970s. The Ann Arbor wastewater plant currently removes most (over 95%) of the phosphorus from wastewater before discharging it into the river. We are doing a very good job controlling the phosphorus in our wastewater.

When phosphorus was first identified as a problem in the Huron River system, the city of Ann Arbor, the Huron River Watershed Council, and other Middle Huron communities relied heavily on public education campaigns and environmental monitoring to inspire voluntary actions that would reduce non-point source phosphorus loading.

In 2007, Ann Arbor developed and passed its ordinance limiting the use of lawn fertilizers containing phosphorus. That came after a decade of investment in public education and research with limited measurable progress toward water quality goals, and a federal mandate (TMDL) to reduce phosphorus levels by 50%.

How Do You Measure a Change in Phosphorus Levels?

Very carefully. Sure, there are sampling and testing protocols to measure phosphorus levels – total phosphorus, soluble reactive phosphorus and dissolved phosphorus. But natural systems are messy and there is a lot of noise in the data. You need lots of good data to measure small changes in the system.

Gathering lots of good data is typically very expensive, and it is rare for it to be affordable by local governments, watershed councils, and even state environmental agencies. Many communities in Michigan and throughout the United States have passed laws regulating phosphorus fertilizers that are similar to Ann Arbor’s. What makes Ann Arbor’s story unique is that it is the only place in the country with good “before” and “after” data. That data show measurable and significant decreases in total phosphorus levels, following implementation of a city-wide ordinance that prohibits the application of phosphorus lawn fertilizers.

Ann Arbor’s data story is better because Dr. John Lehman at UM has a long-term study of nutrients in the Huron River, beginning in 2003, looking at a variety of nutrient levels at key points upstream of Ann Arbor, through Ann Arbor and continuing downstream to Ford and Belleville lakes. The U.S. EPA has supported this effort. This is the part of the story that we like best. Here’s what was going on in 2007:

• EPA had been funding basic research that was not originally intended to evaluate a phosphorus ordinance;
• With this funding, a university professor and students were working on nutrient monitoring in the river and more importantly, they reached out to the watershed community annually to share their research results;
• A separate creekshed modeling effort predicted a significant change (20%) in phosphorus loadings if a ban on phosphorus is implemented; and
• The city enacted a phosphorus ordinance after two years of background work with community partners, knowing that it would have an effect but not sure how much.

Then, quite simply, the parties involved talked to each other.

When we discussed evaluating the effectiveness of our ordinance with Dr. Lehman, he and graduate students proposed a sampling frequency that would measure a statistically significant change of approximately 20%, based on certain assumptions. The city has supported a graduate student to sample at three sites – one upstream control and two in-city experimental sites – for the past two years and again this summer.

Figure 1. Lehman study sampling sites. (Image links to higher resolution file.)

What Do the Phosphorus Data Show?

Phosphorus levels in Ann Arbor’s section of the Huron River have gone down over the past two summers when compared to previous years’ data and upstream controls.

This is really good news. It’s a big deal.

When it dropped the first year, we were “cautiously optimistic” that the phosphorus fertilizer ordinance was responsible for a measurable and statistically significant drop in phosphorus levels in the Huron River. After two years of significant drops, we are more optimistic. But we know we do not have a perfect experiment.

A combination of other factors also can influence phosphorus levels – including changes in behavior resulting from continued public education, increased focus on green infrastructure such as stream buffers and rain gardens, and decreased development in the watershed. It is not clear that any of these, individually or combined, would have an effect at the magnitude we are seeing. Regardless, the data do show real decreases in phosphorus levels, an indication that we are moving in the right direction toward meeting our clean water goals.

A Closer Look at the Phosphorus Data

With Dr. Lehman’s pre- and post-ordinance data, it is possible to compare total phosphorus concentrations for 2008 and 2009 sampling periods to a 2003-2005 reference period.

Figure 2. Sample locations – map reproduced here from Reduced River Phosphorus Following Implementation of a Lawn Fertilizer, Lehman, et al. 2009. (Image links to higher resolution file.)

Sample sites for this study include:

• A control site (see CTL north of Barton Pond in Figure 2 above) located upstream of Ann Arbor. This site receives drainage from outside the area impacted by the phosphorus fertilizer ordinance.
• Sample site A, located on the Huron River upstream of Geddes Pond. This site drains 11 square miles of Ann Arbor.
• Sample site B, located on the Huron River downstream of Geddes Pond. This site drains 36 square miles of Ann Arbor. Because it drains a larger part of the city, site B may be more responsive to the fertilizer ordinance.
• Sample site F, located downstream of Ann Arbor, upstream of Ford Lake.

In the first year of sampling (2008), there were six statistically significant decreases in total phosphorus levels between May and September. Compared to the 2003-2005 reference period, the 2008 reductions ranged from 18-43%, with an average reduction of 28%.

Figure 3. In 2008, six out of ten monthly average phosphorus reductions were statistically significant. An asterisk * indicates statistically significant total phosphorus reduction. (Image links to higher resolution file.)

The 2009 data showed similarly significant reductions in total phosphorus, with an average reduction of 17%. In both years, the total phosphorus reductions were only observed at sample sites A and B, but not at the upstream control site. Further, non-target variables sampled at the same time as phosphorus (e.g., nitrate, dissolved organic matter, silica, specific conductance, and pH) did not change over the sampling period.

Figure 4. Total phosphorus levels were below the average measurement from the 2003-2005 reference period (100% line). The average reduction in TP at site B was 17%. (Image links to higher resolution file.)

At this point in the story, we have two years of good data showing statistically significant drops in phosphorus levels. These data suggest that, over the two-year time period, something was happening in Ann Arbor to cause a decrease in Huron River phosphorus levels that was not occurring upstream and not affecting other nutrients.

What Else Do We Know to Support or Refute Conclusions?

The Huron River Watershed Council, under its Middle Huron Nutrient Monitoring Program, collects data on phosphorus and other variables from tributary streams within and outside Ann Arbor. They also have a growing data set of samples. The results from their data show that after the ordinance went into effect, total phosphorus concentrations (2008-2009 data) for the urban creeksheds were 36% lower on average when compared to pre-ordinance levels. Again, the phosphorus fertilizer ordinance is one explanation for the significant phosphorus reductions in urban creeksheds.

Table 1. HRWC Middle Huron Nutrient Monitoring Program (Ric Lawson). Bold findings are statistically significant. (Image links to higher resolution file.)

Verdict on Phosphorus

So we know that phosphorus levels are still higher than we want them to be and the indicator has been set as yellow.

The upward arrow for the phosphorus indicator reflects an improving trend – that phosphorus levels are going down.

We also know, based on good science and statistics, that phosphorus levels have dropped over the past two summers in Ann Arbor and there is creekshed monitoring data that support the river findings.

So we have set the indicator trend as improving, indicated by the upward arrow.

More on Phosphorus and Ann Arbor’s Ordinance

Phosphorus is an essential nutrient found in all living things, as well as in soils and water. Phosphorus promotes healthy root development in plants.

In Michigan freshwater systems – including the Huron River – phosphorus is the limiting nutrient. In other words, the amount of phosphorus in the system controls the growth of plants and algae. Under natural conditions, phosphorus concentrations in freshwater systems are very low, and plants are efficient at getting the nutrients they need.

When excess phosphorus runs off from lawns into lakes and streams, it quickly accelerates the growth of algae and aquatic plants. One could understand, then, how unnecessary applications of phosphorus on land and subsequent runoff into lakes and rivers can lead to significant surface water quality problems.

Just one pound of phosphorus can stimulate the growth of 500 pounds of algae!

As those algae die and decompose, the decay process consumes dissolved oxygen, reducing the available oxygen supply for fish and other aquatic organisms.

Too much phosphorus contributes to the growth of nuisance aquatic vegetation and algae, not just in Ford and Belleville lakes downstream, but in Ann Arbor’s Huron River impoundments (Barton, Argo, and Geddes ponds). Nuisance plant growth reduces the quality of the habitat for aquatic organisms, and it impacts recreational activities like swimming, boating, canoeing, kayaking, rowing, and angling.

Why Did We Focus on Lawn Fertilizer?

Non-point sources of phosphorus in stormwater include soil and fertilizer run-off. Allen, Malletts, Millers, Swift Run, and Traver creeksheds all contribute high phosphorus loads to the Huron River in Ann Arbor. Reducing the application and subsequent runoff of phosphorus by implementing a formal policy regarding lawn fertilizers provided the city the opportunity to meet water quality goals at a relatively low cost.

Moreover, it turns out additional phosphorus is not even needed for healthy turf in most of southeast Michigan. In general, turf fertilizers are developed for national distribution, and they all contain the three macronutrients required for plant growth: nitrogen, phosphorus, and potassium. Data from Michigan State University (MSU) Extension shows southeast Michigan soils have adequate phosphorus levels, and, in most cases, do not need supplements to support healthy lawns. Plants cannot absorb the excess phosphorus, and it runs off into our waterways.

Another compelling reason to focus on phosphorus fertilizer was the result of a modeling effort that showed a significant reduction in phosphorus loading to the Huron River was possible if there were full city-wide compliance with a fertilizer ordinance. This modeling, completed as part of the Malletts Creek Restoration Study, showed 100% compliance with the phosphorus ordinance in Malletts Creekshed alone would reduce phosphorus loading by 560 pounds per year. Extrapolating to include all Ann Arbor creeksheds, the expected reduction in total phosphorus was 22%. Two years of post-ordinance data show the expected reductions are on target with observations – total phosphorus levels were 28% lower on average in 2008 and 17% lower in 2009.

What Does Ann Arbor’s Ordinance Require?

Ann Arbor’s ordinance applies only to manufactured lawn fertilizers containing phosphorus. In general, it prohibits the application of phosphorus fertilizers. There are exceptions to the rules if you are establishing new turf or if a soil test from the past three years demonstrates a need for supplemental phosphorus.

For lawn fertilizers, the phosphorus-free varieties list “0” as the middle number on the packaging. Phosphorus free lawn fertilizers are readily available from Ann Arbor retailers. Remember to choose “the hero with the zero.”

Phosphorus and the Rest of the River

Ann Arbor is not the only Huron River watershed community with regulations regarding phosphorus lawn fertilizer. Commerce Township, Hamburg Township, the city of Orchard Lake Village, Charter Township of Pittsfield, and Charter Township of Ypsilanti all have similar ordinances. Several other communities and counties throughout the state have passed or are considering phosphorus fertilizer bans.

With more communities pursuing phosphorus regulations, fertilizer companies and suppliers do worry that it will be difficult to comply with a patchwork of phosphorus fertilizer regulations. Many are responsive to a uniform statewide policy. A statewide ban on phosphorus lawn fertilizer, like the one currently being considered in Lansing by Michigan lawmakers, would provide clarity on guidelines among manufacturers and consumers, and it would eliminate the problem of having to keep track of a range of rules.

Michigan House Bill 5368, introduced by state Rep. Terry Brown (D-Pigeon), would prohibit property owners from using lawn fertilizers containing phosphorus unless a soil test indicates the existing phosphorus level is too low, or the property owner is establishing new turf. The bill is currently pending in the Great Lakes and Environment Committee. If passed and signed into law, Michigan would join Minnesota, Maine, Florida, and Wisconsin as states that have passed phosphorus lawn fertilizer regulations in the past five years.

Paths to Contribution

Cleaner water starts in your yard.

We’re all part of the Huron River watershed, and how we take care of the land impacts our local streams, the river and our neighbors downstream.

Keep lawn care pollutants out of the river by following these tips:

• Take proper care of your lawn to reduce or eliminate the need for fertilizer. Maintain the lawn at a minimum height of three inches and, when you mow, cut no more than one-third the height of the grass. Taller grass has a deeper, healthier root system, is more tolerant of drought, and resists weed infestation. When you mow, mulch the clipping back into the lawn to add nitrogen and organic matter to the soil.
• Choose phosphorus-free fertilizer. Most area lawns already have adequate phosphorus supplies.
• Have the soil tested before applying it, if you think your lawn needs phosphorus,. Contact your county MSU Extension office to find out how to submit a soil sample. On Saturdays throughout April, you can bring a soil sample to one of several Washtenaw County retailers for testing by the MSU Extension. See this flier for more information, including instructions for collecting a soil sample.
• Keep fertilizer on the lawn, and off hard pavement. Immediately sweep up any spills, especially on sidewalks and driveways, with a broom. Never wash spilled fertilizers off pavement with a hose.
• Never apply fertilizer right before a storm or to frozen ground.
• Avoid applying fertilizer within 25 feet of any wetland, stream, waterway, or stormwater basin.
• Prevent soil erosion from your property – phosphorus binds to sediment, and finds its way to waterways when soils run off during wet weather events.

In addition to practicing river-safe lawn care, make an effort to purchase other phosphorus-free products. Did you know that some dishwasher detergents can contain up to 8% phosphorus? Choosing low or no-phosphorus products reduces the amount of nutrient that must be removed at the wastewater treatment plant, which is Ann Arbor’s largest source of phosphorus to the Huron River. Beginning July 1, 2010, manufacturers will no longer be allowed to sell detergents with more than 0.5% phosphorus in Michigan.

Voice your support for statewide phosphorus lawn fertilizer legislation. Contact your state representative to speak in support of statewide restrictions on phosphorus lawn fertilizer use. This law will help improve water quality in streams and rivers statewide, and in the Great Lakes.

Finally, celebrate the Huron River this spring, summer and fall.

Get to know the amazing resource flowing through the heart of our city by taking a canoe trip, visiting riverfront parks, or volunteering to keep natural areas in good condition.

Recycling totes and a trash cart await collection in Ann Arbor. The totes will be replaced with bins similar to the blue trash cart in mid-2010. (Photo by The Chronicle.)

Although Matt Naud, the city’s environmental coordinator, is listed as the author of this piece, he received “a boxload of help” from Adrienne Marino, Tom McMurtrie, and Nancy Stone.

The SOE report is developed by the city’s environmental commission and designed as a citizen’s reference tool on environmental issues and as an atlas of the management strategies underway that are intended to conserve and protect our environment. The newest version of the report is organized around 10 environmental goals developed by the environmental commission and adopted by the city council in 2007. This installment focuses on responsible resource use.

All installments of the series are available here: Environmental Indicator Series.

With the closing of the 2009 holiday season, and many of us surrounded by lots of new “stuff” – including the associated boxes and packaging – and even a few of us with New Year’s resolutions to “simplify” our life in the coming new year, it seems like a good time to talk about all of the stuff we buy, use, reuse, recycle, and then throw out in Ann Arbor.

This year, coincidentally, is also the start of our 40th year of recycling in Ann Arbor, starting with a drop off station at Arborland in 1970, some curbside collection in 1978, and in 1991, an environmental bond that brought curbside collection to all Ann Arbor residents.

This installment of the series summarizes our environmental indicators on municipal solid waste (MSW) – the total amount of waste that is landfilled, composted, or recycled in our community.

Putting waste into a landfill has financial and environmental costs. So we look to recycling and composting rates as a measure of success, because recycling and composting divert waste from landfills. Recycling is also one of the least expensive ways for the city to reduce its carbon footprint. The energy used to recycle materials is typically far less than the energy used to create products from virgin materials.

Achieving our current goal of 60% diversion, and our ultimate goal – to produce zero waste – will require more hard work.

Overall, Ann Arbor diverts a large proportion of its total waste compared to other communities statewide as well as nationwide. We begin with a look at national and state patterns, before focusing on Ann Arbor’s indicators.

National Diversion Efforts

Let’s start by taking a look at the national level. The EPA reports that, “In 2008, Americans generated about 250 million tons of trash and recycled and composted 83 million tons of this material, equivalent to a 33.2 percent recycling rate. On average, we recycled and composted 1.5 pounds of our individual waste generation of 4.5 pounds per person per day.”

National municipal solid waste (MSW) recycling rates from 1960-2008. In green is the total tonnage recycled. In orange is the percent of the total stream that is recycled. The divergence of the graphs after 1990 means that even though total recycling has gone up, the U.S. has generated an even greater amount of waste.

(Source: USEPA, Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2008)

Overall in the U.S., 54% of total Municipal Solid Waste (MSW) is discarded in landfills – the rest is recovered through recycling or combusted (i.e., burned) with some energy recovery. [Ann Arbor does not burn any of its waste.]

In the U.S., 54.2% of waste is discarded in landfills, 33.2% is recycled, and 12.6% is burned.

How does Michigan compare to the rest of the U.S.?

State Of Michigan’s Diversion Efforts

The following is taken from Expanding Recycling in Michigan, April 2006, a report prepared by Public Sector Consultants Inc. for Michigan Recycling Partnership:

Ironically, while Michigan is nationally recognized as a leader in conservation and environmental protection, the state is woefully behind its neighboring states and the nation in its MSW recycling efforts.

• Michigan’s recycling rate of 20 percent is lower than the other Great Lakes states (30 percent) and the U.S. (27 percent) averages.
• Michigan’s recycling rate decreased by 20 percent from 1994 to 2004, while every other state in the region had at least a marginal increase in recycling.
• The per capita recycling rate (0.38 tons/year/person) has remained almost stagnant and continues to be below the regional and national averages (0.44 and 0.46, respectively).
• Unlike many states, Michigan does not collect or require reporting of MSW recycling data; therefore, Michigan does not have the ability to measure the state’s recycling performance or its handling, collection, transport, and marketing of recyclable materials.
• Michigan’s recycling program is funded at a fraction of the level of other Great Lakes state programs and ranks 41st out of 48 states that reported their allocations for recycling.
• Only 37 percent of Michigan residents have access to curbside recycling, the lowest percentage of all the states in the region.
• Michigan has not invested in developing or sustaining markets for recycled materials, and some businesses have to import recycled materials from other states because of the inconsistency in local supplies.

So the Michigan story is pretty sad. A recent press release by the Michigan Department of Natural Resources and Environment reported on the decline in solid waste disposal in Michigan and the financial effects:

DEQ Interim Director Jim Sygo warned that the sharp decrease in solid waste disposal would impact the state’s ability to ensure that its waste stream was safe and protective of the environment.

“Michigan’s solid waste program is funded from a 21-cents-per-ton fee on solid waste disposed in Michigan landfills,” said Sygo. “This continued decline in disposal means fewer resources available to our department, and has serious implications for Michigan’s ability to continue the current level of permitting, inspections, and oversight of solid waste management in the state.”

Michigan’s 21-cents-per-ton fee is the lowest in the Great Lakes Region. Based on the capacity used during FY 2009, the reduction of waste disposed, and additional permitted landfill capacity, it is estimated that Michigan landfills have approximately 25 years of remaining disposal capacity.

Maybe it’s just me, but using Michigan land to store trash ought to be really expensive.

Ann Arbor’s Diversion Efforts

Here in Ann Arbor, the story is happier for a number of reasons. Most important is the millage that provides sustainable funding for residential and commercial recycling, including the infrastructure to collect, sort and process these materials for resale. That’s a millage that the city council can enact under state enabling legislation – it appears as “CITY REFUSE” on Ann Arbor property tax bills.

Ann Arbor also has a long history of public education by local government and nonprofits highlighting the benefits of recycling. The Ann Arbor recycling program started in 1970 with a grassroots effort that has continued to today. We have over a 90% participation rate in our single and multi-family recycling program.

Where do we want to be?

One of the city’s 10 environmental goals – responsible resource use – is to produce zero waste. Zero waste is an ambitious goal, but it effectively captures the idea that as a community we don’t want to be wasting resources. While we are not close to meeting the goal of zero waste, every five years we develop a solid waste plan for the city that sets intermediate targets. As we implement the solid waste plan, we move closer to meeting that larger goal.

The goals set in the most recent solid waste plan are:

Achieve a residential waste diversion rate of 60%, equivalent to 31,000 tons/year (for reference, the 1999/2000 recovery was 50%, equivalent to 26,000 tons/year), and an overall diversion goal (including the entire commercial sector) of 60%, equivalent to 40,200 tons/year for both residential and commercial locations.

Our residential waste diversion rate in 2008 was 54%.

In Ann Arbor 46% of solid waste is landfilled, 28% is recycled, and 26% is composted.

Overall we are doing very well compared to measures at the national and state levels. There are several indicators we can use as we look at our overall waste, composting, and recycling initiatives.

Total waste per capita

Landfilled Waste Per Capita

One measurement the city uses as an indicator is the amount of landfilled waste per capita: How much stuff are we each generating on average and how does that compare with some national average?

This number is calculated by weighing the contents of the solid waste residential trucks and dividing by the current census population (excluding the University of Michigan). Looking at the chart below, the amount of waste we are generating per person in Ann Arbor is pretty steady. The good news is that it is lower than the national average. The bad news is that our residential waste disposal is slowly going up instead of down.

Annual Waste Per Capita in Ann Arbor is significantly lower than the national average.

So Ann Arbor’s indicator for total waste per capita is green (our current state is pretty good), with a level arrow (we’re not getting better and not doing dramatically worse).

But this isn’t the whole story.

Looking at annual waste by pound includes all the solid waste we put out to the curb in trash carts. Ways to make our landfilled waste numbers drop include reducing waste at the source (by selecting products in recyclable packaging and purchasing items in bulk) and recycling and composting more.

It is possible to compost food scraps at home (or use your sink disposal) so that heavy organic material that really doesn’t belong in a landfill never makes it into the “waste” stream. In addition, the city expanded our seasonal composting cart collection program this year in fall 2009 – residents can now put uncooked fruits and vegetable food wastes into the compost carts.

Total amount landfilled

Total Landfilled Waste

We’ve already looked at the per-person numbers for landfilled waste. So now let’s take a look at the total amount of waste we landfill.

This is an important measure to look at because it quantifies the amount of material that is now a pure expense to the city and won’t provide any further value – that is, until the economics of mining landfills for materials starts to make sense.

These landfill tons include residential curbside, multi-family, and commercial locations. Data for 2002-2003 are estimated based on 2001 and 2004 data.

Ann Arbor's total amount of landfilled waste is more now than it was in the early 2000s.

This chart shows that we are landfilling less now – in the late 2000s – than we were in the late 1990s. And unfortunately, we are landfilling more than we were just a few years ago.

So Ann Arbor’s indicator for total amount landfilled is yellow (fair) with a downward arrow (we’re doing worse than before).

One thing to note is that landfilling in Michigan is incredibly cheap and not for very good reasons. The true cost of landfilling in Michigan is still pretty high when all of the costs are considered – especially the potential for contaminated groundwater and soils, methane creation, and transportation costs (most recycling facilities are much closer than the landfilling sites).

Past state legislators permitted so much landfill capacity that the beautiful state of Michigan has become a cheap dumping ground for dozens of states and Canada, because Michigan now has a huge over-supply of landfill space. Competition among huge landfills makes the cost for burying trash – the tipping fee – one of the lowest in the U.S.

Even though it makes no sense for Toronto to ship trash to Michigan, Michigan has artificially made it economical for Toronto to send their garbage to us. In FY 2008, Michigan residents sent 39,913,636 cubic yards of waste to Michigan landfills. Canada gave us another 10,722,164 cubic yards, and 6,484,096 came from other states for a grand total of 57,119,896 tons buried in the state of Michigan in just one year.

There are costs that Toronto and other states are not paying that will someday be paid for by Michigan residents.

Tons recycled

Recycling

Recycling is one way to reduce the landfill numbers we’ve already looked at. In Ann Arbor, curbside recycling is provided by Recycle Ann Arbor through a contract with the city. Currently, residents use two stackable totes – a green one for containers and a gray one for paper material.

Ann Arbor’s indicator for total recycled material is green (good) with a level arrow (steady). So what kind of numbers does that indicator reflect?

After a steady rise through the 1990s, the total tons of recycled material in Ann Arbor has leveled off or dropped a bit through the 2000s.

We have dropped a bit in the total amount of material recycled since a high in 2001, but overall our recycling rate has been steady for the past nine years.

To get that arrow for the indicator pointing up is one of the reasons we are looking at single-stream recycling to start in mid-2010 as a way to make recycling easier – toss everything in one cart – to boost our recycling rate and overall amount of waste we are diverting from landfills.

The city currently collects 357 pounds of recycleables per household (HH) per year. Single-stream recycling is expected to raise that amount by 100 pounds to 457 lbs/HH/year. Based on other communities, the addition of the RecycleBank rewards program is estimated to increase recycling to 752 lbs/HH/year – more than doubling the recycleables collected in Ann Arbor. These estimates also account for the expected drop in our total tons recycled because of the loss of the local daily newspaper in 2009.

Tons composted

Composting

Keeping organics that could be composted out of landfills is another way to reduce our landfilled waste numbers.

Ann Arbor’s environmental indicator is green (good) with an upward arrow (improving). What are the numbers that support Ann Arbor’s composting indicator?

Ann Arbor's total tons composted had an upward trend through the 1990s, leveled off, then dropped.

Like recycling, the amount of composted material rose steadily through the 1990s. But composting rates then leveled out, with a big drop in 2007. The numbers for 2008 show us heading back in the right direction. The recent drop is because of a city council ban on grass clippings. They made manually-emptied cans very heavy – but grass clippings are now accepted in the new automated compost carts.

Composting rates are variable and depend on weather – if the year is wet or dry, along with other climatic factors such as ice storm damage, that influences the amount of vegetation collected.

Also, the loss of all the city’s ash trees over the past decade due to the Emerald Ash Borer took a toll by eliminating an estimated 11% of the city’s entire urban forest. Beginning in July 2008, residents began using carts or paper yard waste bags for their compostables. In the fall of 2009, pre-consumer uncooked vegetative food wastes began being accepted in the compost carts’ seasonal pickups.

Percent Diverted

Total Solid Waste: Landfilled, Recycled, Composted

Looking at the individual components of the waste stream – what gets landfilled, recycled, or composted – is definitely useful. But it’s also important to look at the big picture.

When you take a look at the overall picture of waste that is landfilled, recycled, or composted, you get a composite that looks like this.

Total annual solid waste (landfilled, recycled, composted material) has been creeping upward.

It appears that the total amount of waste is down from the high in 2001 but our total waste has been creeping up since 2004.

The measure we look at for an indicator is the percentage of the total waste that is diverted – that is, either recycled or composted. This percentage of diversion is also known as the “recovery rate.”

Ann Arbor’s indicator for total amount of waste diverted is green (good) with a level arrow (stable).

Waste diversion is still fairly high at 41% (citywide, including both commercial and residential) and well above national and state averages. However, it is still lower than our previous high of 46% and well under our intermediate solid waste plan goal of 60%. When we look at just the residential waste stream, we are diverting 54% of the waste stream from landfills.

In 2000, a survey of comparable university communities was developed to benchmark Ann Arbor with peer communities.

       Boulder  Champgn  Madison  Minnpls  OrgnCty  Portlnd  AnnArbor
Pop.   110,700   64,280  200,800  358,785  107,000  505,000  112,000
HH      37,500   24,500   59,200  114,000   48,200  132,000   46,000
SW/day    3.00     3.00     2.53     2.46     3.79     2.75     2.70

PctDiv   36.40    28.20    46.30    29.40    32.20    50.30    39.60
PctRcy   30.40     5.90    19.10    16.60    25.00    27.40    21.60
PctCmp    6.00    22.30    27.20    12.70     7.20    22.90    18.00

ReCurb     513      155      501      384      479      661      727
ReTot      983      203      567      471      345      889      511
Yard       193      771      809      360      401      742      521

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It’s About More than Garbage: Climate

Diversion of material from landfills helps with the management of our solid waste, but it also has a positive impact on reduction of greenhouse gas (GHG) emissions. Emissions of GHGs is an environmental indicator that’s classified by the city as a part of a different environmental goal: stable climate. We’ll take a look at that goal later in this series.

But it’s worth taking a brief look at the relationship between solid waste management and greenhouse gas emissions.

The following is taken directly from USEPA, Methodology For Estimating Municipal Solid Waste Recycling Benefits November 2007:

The disposal of solid waste produces greenhouse gas emissions in a number of ways. First, the anaerobic decomposition of waste buried in landfills produces methane, a greenhouse gas 21 times more potent than carbon dioxide. Second, the incineration of waste also produces carbon dioxide as a by-product. [Note: Ann Arbor does not currently burn any of its waste.] Additionally, in transporting waste for disposal, greenhouse gases are emitted due to the combustion of fossil fuels. Finally, fossil fuels are also required for extracting and processing the raw materials necessary to replace those materials that are being disposed with new products.

The national MSW recycling rate in 2006 was 32.5% (or 82 million tons). Using a WAste Reduction Model (WARM), the EPA has estimated the impact of that 82 million tons of recycling on total GHG emissions: It’s the equivalent of 1,288 trillion BTU – enough to power 6.8 million American households.

In 2003, a team of master’s students from the University of Michigan developed a climate action plan for the city. Using the EPA WARM model, they estimated the emissions avoided in Ann Arbor for the 10-year period from 1991-2001. Note: We have not updated these numbers (yet) using the latest recycling and composting numbers. Here, MTCO2e is the metric ton carbon dioxide equivalent:

Year      Recycling     Composting   Total MTCO2e
1991      20,983.02        977.45      21,960.47
1992      22,075.72      1,356.75      23,432.47
1993      25,630.61      1,530.75      27,161.36
1994      28,098.70      1,737.45      29,836.15
1995      28,254.14      1,973.70      30,227.84
1996      35,740.40      2,184.40      37,924.80
1997      35,997.50      2,865.00      38,862.50
1998      33,570.73      2,302.80      35,873.53
1999      35,247.17      2,262.00      37,509.17
2000      37,713.29      2,397.40      40,110.69
2001      42,086.72      2,536.20      44,622.92

TOTAL    345,398.00     22,123.90     367,521.90

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Following the EPA’s conversion, the 20,000-45,000 range of MTCO2e would translate to a range of savings equal to the energy needed to power 750-1,500 households.

Paths to Contribution

One of the goals of this series is to present some information about who’s already working on improving the city’s indicator scores, and to suggest some specific ways that members of the community can contribute to achieving the city’s environmental goals.

All solid waste, recycling, and composting efforts by the city of Ann Arbor are summarized on the city’s website: “Solid Waste and Recycling”

What can you do on a personal level? First, if you have less stuff, there is less to manage.

Second, reuse the stuff you have. The Reuse Center on South Industrial Avenue is one of several local groups that take items that are still in good shape. You get the tax deduction for your donation, and someone else gets an item they need (or just want more than you do) at a pretty good price. It also doesn’t end up in a landfill.

Personally, I have a new mantle over our fireplace that came from the reuse center, a series of low voltage halogen lights along our entry way, and a Rube Goldberg canoe carrier made from two recycled golf bag carriers. Other local reuse locations are listed online on the city’s website: “Reuse Options”

Third, what you can’t reuse, recycle. That should get easier soon. In mid-2010 the city’s residential and commercial weekly recycling collection program will be expanding to a single-stream program. As part of the upgrade of the city’s materials recovery facility (MRF), Ann Arbor will add and recycle clean plastic bottles and household rigid containers marked #1, #2, #4, #5, #6, and #7. Bulky plastic HDPE #2 items such as buckets, crates, trays, outdoor furniture, and many toys will be accepted.

Three types of plastics that will not be included in the expanded program include items marked with a: #3 (PVC for polyvinyl chloride), polystyrene foam (aka Styrofoam™), and plastic bags or film of any sort.

The city will continue to accept and recycle: glass bottles and food containers; tin/steel cans; aluminum cans, foil, and trays; metal scrap (such as pots and pans up to 1 square foot and 20 pounds/piece); milk cartons and juice boxes; newspapers; magazines and catalogs; corrugated cardboard (including pizza boxes free of food); paper bags; junk mail; office paper; boxboard (e.g., flattened cereal boxes); telephone books; and gift wrapping paper. Clean freezer food boxes will also be recyclable.

What about that old appliance you’d like to get rid of? Effective July 1, 2008, until further notice, the following electronic items are accepted at the Drop Off Station at Platt and Ellsworth at no additional charge beyond the per-vehicle charge of $3/visit: VCRs, stereos, microwave ovens, desktop computers, laptop computers, printers, fax machines, and copiers.

Other interesting efforts:

• Video on Recycling in Ann Arbor
• Ann Arbor Street Art Fair – Zero Waste Events
• Recycling at the University of Michigan

The purpose of sharing this indicator through The Chronicle is to share the State of Our Environment Report with the community and hear what you think. As the city’s environmental coordinator, I will be following any comments readers leave here.

Readers who’d prefer to send an email can use MNaud [at] a2gov.org. An easy chance for an in-person chat would be when the city’s environmental commission meets – the fourth Thursday of each month at 7 p.m. This month’s meeting is today, Jan. 28. Although meetings are typically held in the city council chambers at city hall, the January meeting will be a working session in the 6th floor workroom. City hall is located at 100 N. Fifth Ave.

Overall creekshed indicator for Ann Arbor: fair (yellow) and stable (level arrow).

Editor’s Note: This is the first of what The Chronicle intends to become a series of pieces on the environmental indicators used by the city of Ann Arbor in its State of Our Environment Report. The report is designed as a citizen’s reference tool on environmental issues and as an atlas of the management strategies underway that are intended to conserve and protect our environment. The newest version of the report is organized around 10 Environmental Goals developed by the city’s Environmental Commission and adopted by City Council in 2007.

The first in the series is an introduction to the creeksheds indicator by the city’s environmental coordinator, Matt Naud.

The overall creekshed indicator for the city is yellow (fair) and stable (level arrow). But that overall picture is composed of individual indicators for each of the creeksheds that drain into the Huron River – the central natural feature of Ann Arbor. More than 10 miles of the Huron are located within the city limits.

We assess individual creeksheds, not just the Huron River watershed as whole, because that allows us to focus on exactly the areas that need the most improvement.  Seven different creeks within the city of Ann Arbor flow into the Huron: Allen Creek, Fleming Creek, Honey Creek, Malletts Creek, Millers Creek, Swift Run Creek and Traver Creek.

Individual Creeksheds in Ann Arbor

We used monitoring data from the Huron River Watershed Council to develop the individual creekshed indicator ratings.

The Huron River Watershed Council collected and analyzed the original data and provided input on the final indicator ratings. Adrienne Marino, an environmental programs assistant in the city’s Systems Planning Group, developed the indicator pages and maps associated with each creekshed. Each of those pages provides a description of current conditions and links to more detailed fact sheets for each monitoring site within a creekshed.

The indicator icons below link to the respective pages for each creekshed (green is “good,” yellow is “fair,” red is “poor” – the level arrow indicates “stable”):

Allen Creek

Fleming Creek

Honey Creek

Malletts Creek

Millers Creek

Swift Run Creek

Traver Creek

While the colors correspond to what seem like subjective judgments of “good,” “fair,” and “poor,” those evaluations reflect a quantitative analysis. And the arrows reflect that this analysis has been performed over time for an evaluation of “stable” – neither getting better nor getting worse.

Data on Creeks: The Adopt-a-Stream Program

The long-term monitoring data on the physical and biological stream conditions – which we use for determining the creekshed indicators – are available through the Huron River Watershed Council’s Adopt-a-Stream Program.

The HRWC’s Adopt-a-Stream Program includes more than 400 volunteers, who monitor biological communities, water quality, and stream habitat at 71 river and tributary sites across the Huron River watershed.

What kind of data are gathered? On a single day in April and September of each year, a mix of trained and casual volunteers collect a sample of the benthic macroinvertebrate population at the stream sites. In January, volunteers search for winter stoneflies. During the spring, fall, and winter monitoring, volunteers collect a sample of stream water to measure conductivity. Volunteers also measure the weekly in-stream maximum and minimum temperatures in July and August, and assess the habitat quality of each study site once every few years.

What does this data look like? Here’s an excerpt from the Fleming Creek survey:

Site #   Location           Insects    EPT   Sensitive   5-yr trend
  9      Fleming Creek:        12       7        2        Stable
         Botanical Gardens

Counts refer to the number of families caught.
EPT: Ephemeroptera-Plecoptera-Trichoptera (Mayflies-Stoneflies-Caddisflies)

–

For the complete Fleming Creek survey report as well as the other Adopt-a-Stream data, visit the HRWC Adopt-a-Stream Monitoring Reports web page.

In more detail, the biological measures include:

• Number of insect families: Insect diversity, as measured by the number of different aquatic insect families, indicates good stream quality. Greater diversity at a site means the water is unpolluted, and there are healthy conditions for a variety of creatures.
• Number of sensitive insect families: Many benthic families living in the Huron River system are sensitive to organic pollution. The presence of these sensitive families at a site indicates that the site, and the upstream portion of it, has high quality.
• Number of EPT families: EPT denotes Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies). Many mayflies, stoneflies, and caddisflies are sensitive to the quality of a site, and a variety of these families present at a site is another indicator of good water quality.
• Number of winter stonefly families: Stonefly nymphs are extremely sensitive to most pollutants, and they cannot survive if a stream’s dissolved oxygen concentration falls below a critical level. Presence of winter stonefly families is indicative of high water quality.

Physical measures include:

• Habitat assessment score: Based on creekshed-wide measurements of land cover, land use, and percent impervious surface, as well as site-specific habitat measurements including stream bottom composition, water temperature, and width of riparian vegetation. Some indicators of a high quality stream include stable banks with a broad corridor of native vegetation, riffles free of silt deposition, and stable water temperatures.
• Conductivity: An estimate of the total dissolved salts, or ions, in the water. A conductivity measurement of 800 µS is considered normal for the Huron River system.

Analysis of Creek Data

How are Adopt-a-Stream data analyzed? HRWC staff use the Wiley Stream Health Model, an integrative model created for the Huron River system by University of Michigan aquatic ecologist Dr. Mike Wiley. This model uses information about aquatic insect populations, stream habitat, stream temperature, and stream size – the kind of data collected through the Adopt-a-Stream program – to predict the overall health of a stream or river. Specific model inputs include biological and physical habitat measures.

In 2008, HRWC staff re-calibrated the model to the most recent data, and they have used it to make evaluations of stream health in the Huron River watershed.

The scores calculated using the Wiley model reflect the difference between expected versus observed numbers, measured in standard deviations. Adopt-a-Stream monitoring sites are thus rated as poor, fair, good, or excellent based on the Wiley Stream Health Model output. The descriptions corresponding to scores are as follows:

• >1   Excellent. Much better than an average stream of the same size
• >0  Good. Slightly better than an average stream of the same size
• <0  Fair. Slightly worse than an average stream of the same size
• <-1  Poor. Much worse than an average stream of the same size

So who decides what the overall indicator icon should look like – where we are now and where we are going? For the most part, it is the city’s environmental commission, and specifically the State of Our Environment committee, that makes that determination. That committee meets monthly to review the indicators, update the data, and decide on what new indicators can be developed to help reflect our progress (or lack thereof) toward our environmental goals.

The city’s environmental commission also makes decisions about where indicators fit within the city’s 10 environmental goals. For example, the creekshed indicator is a part of the Viable Ecosystems Goal, not the Clean Water Goal. While many of the indicators could fit under more than one of the city’s environmental goals, the  environmental commission made a decision to place each indicator under just one goal to simplify the presentation.

Paths to Contribution

One of the goals of this series is to present some information about who’s already working on improving indicator scores and to suggest some specific ways members of the community can contribute to achieving the city’s environmental goals. All water resources planning initiatives by the city of Ann Arbor are summarized on the city’s website.

For Allen Creek specifically, the Allen Creek Stormwater Initiative is a planning group that includes Ann Arbor Public Schools, University of Michigan, Allen Creek Watershed Group, Allen Creek Greenway Conservancy, Friends of West Park, the Huron River Watershed Council, and Peter Allen & Associates.

A website created as part of the Millers Creek Watershed Improvement Plan, funded by Pfizer Global Research and Development, summarizes and organizes activities for Millers Creek. One example is the Millers Creek Film Festival, which has an entry deadline of Feb. 2, 2010 – winning entries will be shown at the festival on March 19, 2010 on the big screen at the Michigan Theater.

Materials on the Malletts Creek Restoration Plan and contact information for the Malletts Creek Association are hosted on the county’s water resources commissioner’s website.

The water resources commissioner also operates a Riversafe Homes program for homeowners as a part of its water quality efforts.

And for all creeksheds, the HRWC Adopt-a-Stream program is a way for people to actually get out into the environment and lend a hand with data collection.

The purpose of sharing this indicator through The Chronicle is to share the State of Our Environment Report with the community and hear what you think. As the city’s environmental coordinator, I will be following any comments readers leave here.

Readers who’d prefer to send an email can use MNaud [at] a2gov.org. An easy chance for an in-person chat would be when the city’s environmental commission meets – the fourth Thursday of each month at 7 p.m. in the city council chambers at at city hall. Because of the Thanksgiving holiday, the commission’s next meeting is on Thursday, Dec. 3.