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The following information was recently posted to NPSINFO. The complete text of posts and responses has been included below so readers can get the flavor of the breadth and depth of many NPSINFO discussions. For privacy purposes, we have withheld the names and identities of the subscribers who posted the information below. Please select a question below to go directly to that question, or scroll down to view all.

  1. Does anyone know of local ordinances or state laws that are effective in restricting livestock access to streams and rivers?
  2. Does anyone know where I can find economic data on the cost of beach closures?
  3. Does anyone have ordinance language on how municipalities are funding the purchase of open space?
  4. Does anyone on the list have experience with selecting BMPs for areas with low infiltration capacity?
  5. Green roofs are becoming more popular for large city buildings, but what about marketing them to homeowners?
  6. I am seeking examples of state and local government laws restricting the use of phosphorus fertilizer.
  7. How do I quantitatively compare the water quality benefits gained by restoring streambanks versus maintaining a certain width of riparian buffer? We would like to provide developers with the option of restoring streambanks in exchange for reducing riparian buffer widths.
  8. You are invited to a free Webcast on Implementing TMDLs and Trading Through the National Estuary Program.

POST #1: Does anyone know of local ordinances or state laws that are effective in restricting livestock access to streams and rivers?

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This question was excerpted from the following posting:

As the Chair of a Soil and Water Conservation District (SWCD) in the Chesapeake Bay watershed, I am becoming increasingly frustrated by the difficulty in securing voluntary participation by landowners in our programs to reduce nutrients and sediments contributed by livestock from impacting Bay watershed streams and rivers. Virginia is in the process of promulgating strong regulations to severely limit nitrogen and phosphorus discharges from municipal and industrial wastewater treatment facilities discharging into streams and rivers in the Bay watershed, and imposing a nutrient cap on discharges from those facilities to help meet the nutrient reduction targets established by agreement of the Bay states and the District of Columbia. Virginia will likely provide substantial tax dollars for upgrading municipal systems to meet the new standards.

The imposition of these new regulations will make mandatory the compliance with the new regulations through the Virginia Pollutant Discharge Elimination System (VPDES) permit program. Local governmental entities and industries will need to accommodate the increased costs. System users will help pay these increased costs. By way of contrast, we have no regulations limiting pollution contributed by nonpoint sources. While we have a nutrient reduction goal for such discharges under the Bay program, no cap is proposed. At the same time, we have state taxpayers' dollars (and a very modest level of federal dollars) providing up to 75 percent of the cost of installing agriculture best management practices. So it is not as if the landowner would be providing all of the cost to correct pollution problems being created by his or her agriculture operations.

We have an ineffective Agricultural Stewardship Act that allows individuals to submit complaints to our Department of Agriculture if they believe they have identified an agriculture-related non-point pollution source. The Dept. investigates such complaints and a local SWCD may assist and then help in the development of a remedy to the complaint. But such complaints are few and far between. Few individuals are willing to complain about their neighbors. Our state TMDL efforts also have no teeth.

Does any NPSINFO reader know of local ordinances or state laws that are effective in restricting livestock access to streams and rivers? It is locally evident that a substantial share of the nonpoint pollution contribution comes from agriculture land and a substantial share of agricultural source pollution comes from livestock. Your observations and suggestions will be deeply appreciated.

RESPONSE 1a: I am sure it is just baby steps in the grand scheme of things, but in South Carolina our small firm has had pretty good luck getting volunteer compliance with livestock owners over the last five years using Clean Water Act section 319 grants. Once we teamed up with Clemson extension agents who live and farm in the communities we targeted, we got big turnouts at outreach 'farm tours' showing alternative water sources and stream exclusion. To date, we have grants in eight watersheds that range in size, and we have enough interested farmers that are willing to cost-share to make the improvements we recommended that we are almost running out of money. This was not the case at first. It took a while to gain trust and community awareness. We're still not talking huge numbers, but 20 landowners, including some folks with over 100 cows plus calves in a pretty small geographic area, will hopefully have a positive impact in the future. Our experience is that being on their 'team' and not pointing the finger helps a lot.

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RESPONSE 1b: I've been working in the agricultural BMP/water quality area for a good many years now. At first, it seemed like everyone looked at me like I was from Mars, even though I grew up on a small farm and speak the language, know the concerns, etc. Now most folks want to know about alternative watering systems.

One of the things you will run into is the farmer's suspicion of "I'm from the government and I'm here to help you folks." Usually that means that it costs the farmer money to implement something that is more labor intensive and aggravating to maintain and that may not work as well as the previous setup. We all understand the benefits of livestock exclusion from streams and rivers, but that idea can be fairly abstract to a farmer that is being asked to devote $2,500 (after cost sharing) and a few weeks' labor to stream bank fencing. Livestock prices are up right now, which can help. During low price times it's really a struggle, especially for small farmers with extensive stream access.

The best thing you can do is to get some nice-looking, workable practices in place with some good managers. The surrounding farmers will see these practices, think on it for a few months or years, and after they see it works well, they'll join in. That also has the benefit that they "buy in" and maintain the systems -- a very important point. Sharing information by long-term demonstration goes a lot farther than Powerpoint presentations and regulations. Right now we have entire counties where alternative watering systems are viewed as a good idea and are something most farmers are working toward. I know that's long term, and most folks demand action now! But we didn't get to this point overnight. A good solution is going to take a few years to be accepted and implemented.

An alternative watering system providing well water can reduce livestock impacts on stream banks substantially without fencing. The folks at Virginia Tech did a study on that a number of years ago; cattle residency times in the streams dropped by around 70 percent or so, if I remember correctly. Nutrient loading was reduced even more (as was sediment, I think). That's also worth a look.

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RESPONSE 1c: It sounds like there are some difficulties, obstacles, tension, frustration, and lack of desired progress in getting implementation of appropriate BMPs by livestock producers to protect and restore water quality in your area. I am sorry for the difficulties. Here in Utah, an arid state, we do not have the intensity of animal feeding operations (AFOs) that you have on the Bay. Livestock production is a very significant part of the history and heritage in our area, and lacking the moisture and rich soils to produce significant high value crops, livestock production is THE major agricultural endeavor in Utah.

Several years ago, we recognized polluted runoff from AFOs as a significant problem that must be remedied. Rather than approaching the problems from an adversarial, regulatory perspective, Utah determined to try to work cooperatively, in harmony with agricultural producers to inform and assist them in revising livestock management to NRCS standards to prevent runoff of wastes and prevent nutrient or bacterial loading. Several offices and organizations developed a cooperative relationship to address the AFO/CAFO problems in Utah. These include: Utah Department of Environmental Quality, Utah Department of Agriculture, Utah Farm Bureau, Utah Association of Conservation Districts, USDA/NRCS, Dairyman's Assoc., and numerous others. The Utah Department. of Natural Resources has also been essential in working with landowners to implement BMPs to restore fishing habitat and riparian protection on many streams and rivers in the state.

That attached report describes progress that has been made. A significant component has been that a representative from either Utah Farm Bureau or Utah Assoc. of Conservation Dist. has visited essentially every AFO in our state to cooperatively review the conditions and status of waste and nutrient management with each livestock producer. Where problems have been identified, they have been or are being addressed. Where facilities improvements or upgrades are needed, and there have been many, technical assistance and some financial assistance have been sought.

We anticipate having nearly all of our approximately 3,000 AFOs be managed satisfactorily within the next three years so that essential no polluted runoff comes from any AFO. At least that was the original plan, but it appears that we may reach that goal sooner, as AFOs with significant runoff problems identified are implementing appropriate BMPs faster than anticipated. NRCS secured additional funding to assist producers in their efforts. The cooperative effort appears to be working very successfully. We found that keeping livestock out of the streams was only one part of the problem. Additionally, manure management, nutrient management, livestock management, riparian restorations, and many other factors have been implemented successfully on farms where problems have been identified.

Here in Utah, we are finding that a cooperative program of information, guidance, and assistance (with the understanding that if you don't get it voluntarily, rules and regulations and fines will eventually follow) is working much more effectively than the punitive, regulatory programs we hear of elsewhere.

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POST #2: Does anyone know where I can find economic data on the cost of beach closures-preferably specific to the Northeast United States? I was able to find some San Diego numbers (approximately $30,000 for a two day closure in tourist dollars not spent in the community). Does anyone have any other numbers?

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RESPONSE #2a: This is a short summary of what I found for the cost of beach closures:

  • "At the Beach: Ecology and Economy - America's Finest City? San Diego is first - in beach closures," by Carolyn Chase San Diego Earth Times, 1996. Beach closures are one example of how polluted runoff puts these tourist dollars at risk. According to the report, closing a San Diego beach for two days costs the local and state economy $30,525 (www.sdearthtimes.com/et0196/et0196s1.html)
  • "TESTING THE WATERS 2004: A Guide to Water Quality at Vacation Beaches," Natural Resources Defense Council, August 2004. EXCERPT: one study estimated economic losses as a result of closing a Lake Michigan beach due to pollution as ranging between $7,935 and $37,030 per day.
  • "CA Study Finds $3.3 Million Cost Linked to Illnesses from Swimming." A recently published economic study estimated that illnesses linked to swimming in polluted coastal waters at two popular Southern California beaches cost the public about $3.3 million a year. The study focused on Orange County's Newport Beach and Huntington Beach and used local public information and data from earlier scientific studies. Researchers estimated that among the 5 million swimmers that visited the two beaches from 1998 to 2000, each year there were an average 36,778 incidents of gastrointestinal illnesses and 38,000 other ailments, including respiratory, eye, and ear infections. Researchers estimate that if bacteria levels in these coastal waters were exactly at accepted levels, the total health cost would be greater than $7 million per year. "Valuing Water Quality Advisories and Beach Amenities in the Great Lakes." Water Resources Research. 37(10) 2583 - 2590. Yeh,C. B. Sohngen, T. Haab. 2002. "Modeling Multiple-Objective Trips with Choices over Trip Duration and Alternative Sites." In Review.
  • www.latimes.com/news/local/la-me-beaches3may03,1,4149497.story?coll=l. By Sara Lin, Times Staff Writer, May 3, 2005. Excerpt: The economic cost of exposure to the waters off Huntington and Newport beaches is about $3 million in a typical year, not counting illnesses contracted on days when bacteria levels exceed state health standards, according to a UC Irvine study. The cost is the combination of lost wages and medical care, excluding self-treatment. An illness episode in this study means the person becomes ill enough to miss work and/or seek medical care. (Source: Environmental Health Science and Policy Program, UC Irvine.) The following numbers represent the total cost (2001 dollars) per episode of illness, by type:
    • Acute respiratory disease: $76.76
    • Ear ailment: $37.86
    • Gastrointestinal: $36.58
    • Eye ailment: $27.31
  • Also, see www.bol.ucla.edu/~linwoodp/monitor.pdf, "Harnessing Ocean Observing Technologies to Improve Beach Management." By Linwood Pendleton, Associate Professor Environmental Science and Engineering Program, School of Public Health, University of California, Los Angeles.

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RESPONSE 2b: See information for the Great Lakes at the following site: http://aede.osu.edu/people/sohngen.1/beach/beachin.htm. Also, I have two papers on this subject. The first I can send in hard copy. The second I can send via e-mail.

  1. Murray, C., B. Sohngen, and L. Pendleton. 2001. "Valuing Water Quality Advisories and Beach Amenities in the Great Lakes." Water Resources Research. 37(10) 2583-2590.
  2. Yeh,C. B. Sohngen, T. Haab. 2002. "Modeling Multiple-Objective Trips with Choices over Trip Duration and Alternative Sites." In Review.

**A lot of cost analysis was done by USEPA for the draft Sanitary Sewer Overflow rule, and the contractor got some Atlantic data from: www.surfrider.org/stateofthebeach/home.asp

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POST #3: Does anyone have ordinance language on how municipalities are funding the purchase of open space?

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RESPONSE #3a: Here is something from Burlington, Vermont: Burlington Open Space Plan (www.ci.burlington.vt.us/planning/osplan/master.html)

RESPONSE #3b: Washtenaw County (SE Michigan) and Ann Arbor (in Washtenaw County) have passed millages for purchase of open space (outright and PDRs-purchase of development rights) and farmland. Try www.ewashtenaw.org and http://www.ci.ann-arbor.mi.us

RESPONSE #3c: Pennsylvania developed a series of guidance documents that may be helpful in establishing boilerplate language:

  • Growing with Green Infrastructure (www.heritageconservancy.org/news/publications/pdf/green_infra.pdf)
  • Implementing a Municipal Open Space Program: A Guide for Pennsylvania's Municipalities (www.dcnr.state.pa.us/brc/Quality%20of%20PlaceLife%20Web.pdf)
  • Opportunity Knocks: Open Space is a Community Investment (www.heritageconservancy.org/news/pdf/opportunity.pdf)
  • Public Finance for Open Space: A Guide for Pennsylvania's Municipalities (www.dcnr.state.pa.us/brc/Public%20Finance%20Web.pdf)
  • Using Conservation Easements to Preserve Open Space: A Guide for Pennsylvania's Municipalities (www.dcnr.state.pa.us/brc/Easements.pdf)

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POST #4: Does anyone on the list have experience with selecting BMPs for areas with low infiltration capacity? In stormwater impaired watersheds there is a growing push for zero discharge. For existing neighborhoods with poor soils this appears to be a tall order. Can anyone direct me to resources for meeting retention and treatment needs under these conditions?

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RESPONSE #4a: If the soils are that poor, why zero discharge? There must have been some runoff for pre-development conditions, unless you are in a truly arid or semi-arid region, which I don't believe Vermont qualifies as. I would suggest having a look at what they have been doing in Australia. I recently was asked to prepare a book review of a new handbook entitled "Water Sensitive Urban Design: Basic Procedures for 'Source Control' of Stormwater." The handbook isn't perfect, but it very interesting and definitely thought provoking. See www.wsud.org/tech.htm.

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RESPONSE #4b: I organized three workshops (1-2003 & 2-2004) on Sustainable Stormwater Management (using bio-swales, cisterns, green roofs, rain gardens, porous pavement, level spreaders, French drains....). The last one tackled the clay soils issue. If you would like to discuss what we did, please feel free to give me a call.

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RESPONSE #4c: In New Jersey, you are supposed to meet both quality and quantity rules (www.njstormwater.org) unless you show that existing conditions do not allow infiltration. In those situations, you should be looking for BMPs that focus on quality, (e.g., things like Stormfilters and Stormceptors). These units are not cheap but they do work. Other expensive options are underground storage reservoirs. Another option is to perhaps dig relatively small bioinfiltration areas that will fill up and overflow in larger storms but will hold water in smaller storms and let it infiltrate slowly. Rain barrels are another option.

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RESPONSE #4d: Here are some websites to get you started:

  • www.lid-stormwater.net
  • www.cdfinc.com/CDF_Portfolio/Regional_Scale/Blackberry_Creek/Blackberry_Creek_Final_Report.htm
  • www.ciria.org/suds
  • www.psat.wa.gov/Publications/LID_studies/LID_approaches.htm
  • www.toolbase.org/tertiaryT.asp?TrackID=&CategoryID=1232&DocumentID=2007
  • www.cityofchicago.org/Environment/GreenTech
  • www.metrokc.gov/procure/green/bul71.htm

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RESPONSE #4e: Often we are looking at non-structural drainage systems that use modified soils, many times in conjunction with geosynthetics.

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RESPONSE #4f: We have a fair amount of clay soils with low infiltration capacity as well. From my research, the most effective BMP appears to be bioretention cells (e.g., landscape detention) with an impermeable liner and an underdrain system. The liner is required where you have expandable clays. In the Reno, NV area the majority of runoff captured by these devices would be lost to evapotranspiration. In Denver, the filtered runoff that is released from the underdrain to the conventional storm drain system is not considered in post development flow calculations because it takes such a long time to drain out of the soils. We're really pushing to require developments to incorporate bioretention cells because numerous studies have shown that they have high pollutant removal capability and help to restore the natural hydrologic cycle by reducing runoff and increasing groundwater recharge. If distributed throughout the project, developers can actually save money by not having to install conventional underground storm drain infrastructure. They can also effectively reduce runoff and result in zero discharge for all but the 100-year storm events. So it's important to incorporate overflow structures and conveyances for the rare large events. Here are some useful links with design info on bioretention cells/landscape detention:

  • www.lowimpactdevelopment.org/resources.htm
  • www.stormwatercenter.net
  • www.udfcd.org

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RESPONSE #4g: We run into this situation frequently, and in response use oversized storage instead of infiltration. Generally we try to store at least the first inch of rainfall, preferably up to a two-year storm using excavated, crushed stone-filled underground reservoirs in some instances. Alternative ly, we have also used wetlands treatment with storage built in if soils are poor, such as in areas of high groundwater if there is adequate space. By the way, we do a lot of plan reviews and often find developers using poor soils as an excuse to avoid doing anything at all, saying that the pre-development condition (forested with poor soils) is equal to the post-condition (paved with poor soils). Not likely in real life.

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RESPONSE #4h: Green roofs are an up-and-coming technology. They can delay or eliminate runoff from very small storms. We did a report on the problems of low infiltration capacity and a potential remedy by adding compost to soils to improve infiltration capacity (www.epa.gov/ednnrmrl/reports/SR00016/epa-600-r-00-016.pdf). When installing BMPs, it is critical not to compact the soil with heavy earth-moving equipment. Bioretention cells (small BMPs) may be effective as retrofits. Plantings can include trees. These typically slow runoff and more often than not require an outlet. One cell typically can handle up to an acre. Guidance is available in Volume 2 of a design guide our group put together (www.epa.gov/ORD/NRMRL/pubs/600r04121/600r04121a.pdf). You can find other resources for this BMP in state guides or other EPA websites. We have other publications available at our Web site.

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RESPONSE #4i: We are still struggling with clay soils here. You may want to look at the Conservation Design Forum Web site for ideas about using native plants. After several years, deep-rooted plants increase infiltration in these soils. CDF has done quite a few projects in the Chicago area (see www.cdfinc.com)

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POST #5: Green roofs are becoming more popular for large city buildings, but what about marketing them to homeowners?

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This question was excerpted from the following posting:

It appears that the majority of green roofs are constructed for municipal or large, high-rise types of developments. My guess is that they are expensive to construct, and the typical homeowner would not have the resources to build one. We thought it would be beneficial to perhaps market this technique to homeowners, builders (others?) and are in the process of developing a fact sheet on green roofs (our lab sees a couple thousand homeowners each year). Perhaps it could start with small sheds and garages and eventually expand. We are also developing a rain garden fact sheet for homeowners and hope to provide some local training to gardeners, landscapers, etc. A few questions:

  1. Is it worth the time and energy to try and sell this technique to homeowners?
  2. If so, what are some good contacts?
  3. What is the approval process for installing a green roof? Is there a specific building code, variance...?

RESPONSE 5a: We're grappling with what to say about green roofs and stormwater for commercial and residential buildings, and what we're running into is that the drivers for green roofs appear to be less about stormwater and more about energy savings. Massachusetts requires that new development (and redevelopment, to the maximum extent practicable): (1) reduce TSS 80 percent, (2) reduce peak discharge, and (3) recharge a volume of 0.4 inch (soon to be 0.6 inch).

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Green roofs do not reduce TSS* from the property, so they will not get any TSS credit. To the extent that they hold moisture and retard runoff, they do peak-discharge work. Since they do not "infiltrate into the ground," they should get no recharge credit. Arguably they make the impervious rooftop act more like a pervious surface (hold moisture in soil, do transpiration) so we would give them an LID credit (i.e., remove the roof from the calculation of impervious surface when calculating required recharge and water quality volumes). [*NPSINFO Editor's note: Green roofs can reduce overall TSS indirectly by reducing stormwater runoff, which in turn reduces the amount of TSS generated by erosion.]

Do these observations make sense to you? If so, as a homeowner I'm unlikely to put in a green roof for stormwater purposes. So the marketing would tilt more toward:

  1. Energy savings
  2. Excellent tool for personal commitment to better water use on site (better than just sending roof runoff to cisterns or rain barrels)

I wonder if the snow load calculations for roofs are stout enough to also pass muster for the soil loadings of green roofs.

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RESPONSE 5b: You're right-most installations have been for municipalities and larger structures. Primarily, roof design for houses have sloped roofs, which requires greater expense for installing a green roof. Also, homes are typically wooden frame structures, whereas larger buildings are steel-framed. You can put a green roof on the top parking deck of any multistory parking lot without fear, but putting on individual homes may require investigating loading capacity and reinforcement in some cases. At a minimum, you need to exceed snow load for the roof.

I think the homeowner market could be developed but should be aimed at additions and new homes. Farmers could benefit from having animal shelters with green roofs, because it will keep interior cool.

  • http://hortweb.cas.psu.edu/research/greenroofcenter/about_ctr.html
  • http://hortweb.cas.psu.edu/research/greenroofcenter/about_ctr.html
  • www.greenroofs.org/minneapolis

We're seeing a 50 percent reduction in annual runoff from roofs and, more importantly, over 90 percent complete capture of storms up to 0.5 inches (the small storms that drive many of the pollution problems).

For more information for bioretention cells, see:

  • www.state.nj.us/dep/seeds/syhart/rgmp1.pdf
  • www.bae.ncsu.edu/topic/raingarden

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RESPONSE 5c: I guess bright folks have already thought about wind damage and danger of falling debris from high-rise roof gardens. Streets in downtown Toronto have been closed this past week because of ice accumulation and falling ice. I see what appear to be shrubs up there and would be interested to learn of any specs securing green roof plants against high winds.

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RESPONSE 5d: I'd also be interested in hearing if there is evidence of ice accumulation causing problems. I'm in Massachusetts, and I'm in a home with pitched roofs constructed in 1950. I agree with a previous poster that as a homeowner, a green roof doesn't stand out as a stormwater option. I would focus on the multitude of benefits that a green roof provides.

The Boston Globe Magazine recently (2/4/07) did an issue on green homes. A Waterville Valley, New Hampshire, house was built into the side of a hill, and the photo shows roof gardens. The magazine gave the architect contact info: Donald Jasinski, Jasinski Architects International, 603-236-2008, www.jasinskiai.com.

You requested a good contact, so I offer George Irwin. I've found him to be a wonderful source of information and very responsive. Here is his contact info: George Irwin, Green Living Roofs, LLC, 1-800-631-8001, www.AGreenroof.com, Info@AGreenroof.com, george@agreenroof.com.

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RESPONSE 5e: It looks like the Twin Cities may be ahead of the curve. Maybe they have some good information to share: www.twincities.com/mld/twincities/living/16761312.htm

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RESPONSE 5f: I hope this addresses some of the other questions. Anecdotal evidence has shown that ice does not accumulate on the green roofs any more than on regular flat roofs. This was also observed during a study conducted at Penn State. I hope to post this final report to our Web site later in the spring.

Flat roofs use rock ballast to prevent the lining from being ripped up by high winds. Extensive green roofs use similar ballast with a little compost added, and they use sedums as plant material. These small rock garden plants do not grow that tall (3 inches max?). Extensive green roofs are the typical installation and are 3-6 inches in depth.

Intensive green roofs require deeper soil (> 1 foot) and could support other plants like bushes, and, as with any penthouse garden, there is the potential of a branch breaking off or debris being windswept. Safety design would need to take this into account. Intensive planting requires a stronger root barrier. Extensive green roofs are more practical and require a smaller load-bearing capacity.

As stated, extensive green roofs serve a multitude of purposes: stormwater, reduce air conditioning requirement, reduction of urban heat island effect, aesthetics, potential habitat, and extended roof liner life.

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RESPONSE 5g: Green roofs are a great resource to simulate the evapotranspiration (ET) process of day-to-day stormwater management. You don't need a lot of infiltration to recreate the pre-construction infiltration (like the 0.4 inch mentioned by a previous message). The big problem is the ET. Green roofs, in concert with raingardens, probably do a lot better than large infiltration rock beds at getting back to pre-construction conditions. In Philadelphia, when we capture about an inch of rainfall we are probably gaining a removal of 75 to 85 percent of the rainfall. If this is implemented on a regional scale, it should help reduce impacts of downstream flooding and streambank erosion. Remember that a LOT of the total suspended solids (TSS) is from elevated stream bank erosion, so I would argue that green roofs do aid in TSS removal.

When we really start designing for long-term infiltration, we may find green roofs and rain gardens are more cost-effective when we look at life cycles. I doubt many green roofs will remove enough volume unless we do add the rain gardens. I also agree that green roofs are mostly going to be focused at high impervious sites, not homeowners. For areas where you need more than the 0.4 inch recharge, I would hate to see the use of green roofs discouraged for not meeting TSS or volume reduction.

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RESPONSE 5h: The May 2005 issue of This Old House magazine has an article on green roofs geared toward the homeowner. Unfortunately, it is not on their Web site. It includes a cut-away drawing of layers of roof materials for waterproofing and plant growth.

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POST 6: I am seeking examples of state and local government laws restricting the use of phosphorus fertilizer. Minnesota was the first state to pass legislation restricting the use of phosphorus lawn fertilizer. Part of the law requires that the Minnesota Department of Agriculture reports to the Minnesota legislature in 2007 on how the law is working. I am writing that report. Of interest to our legislators will be the occurrence of other similar legislation passed by other states and local units of government restricting phosphorus fertilizer use. If you know of such legislation, please provide a contact and/or web link for more information.

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RESPONSE 6a: Maryland has been looking into this issue. Last year we had a small conference on urban nutrient loadings. The conference included industry representatives and we learned some interesting things. bIn Maryland we have a law that says that if you are an agriculture operation that makes more than $2,500 per year, than you have to have a nutrient management plan. The law was aimed at farmers but also applied to lawn care companies. As required by the law, Chem-Lawn performed soil tests. The tests showed that almost all of the lawns in Maryland have enough phosphorus; therefore, Chem-Lawn has stopped including phosphorus in their routine fertilizer applications in Maryland.

Based on the conference findings we started to look at a law similar to Minnesota's. At this point we also started discussions with Scotts, the fertilizer company. I think Scotts wanted to head off any legislation. The results of these discussions were that Scotts has agreed to cut the amount of phosphorus in their fertilizer in half. This was calculated based on pounds of fertilizer sold in the region. They plan to make this cut nationwide, not just in the Chesapeake Bay states. They also agreed to begin to market a "phosphorus-free" line of fertilizer. Scotts also indicated that they would work with us to educate people on proper fertilizer use and that we would look at nitrogen and pesticides in the future. Based on this agreement, the push for phosphorus-free legislation has died for now in Maryland. If you are thinking of legislation you may want to talk to Scotts because the steps they are already taking may stymie any of your attempts.

While I prefer forest to lawns, the fact is that lawns are good at taking up nutrients. Phosphorus for the most part adsorbs to soil and is not very mobile unless you have very high concentrations. Soil loss from lawns is fairly low. Nitrogen, on the other hand, can move. However, in Maryland we have been doing a lot of water quality sampling-especially in early spring before leaf-out. In general, we do not find high nitrogen levels in spring base flow in urban areas that have a sewage system. We do find elevated nitrogen levels in areas that are on septic systems. If nitrogen from lawns were a problem, you would have elevated nitrogen levels in urban ground water.

A few more things we learned from Scotts. The majority of homeowners (>50 percent) do not fertilize their lawns. Of those that do fertilize them, most do it only once or twice a year. I think the biggest problem is the timing of when people fertilize. Most do it in the spring when most of the nutrients go into stem growth (for temperate/cool climate grasses). If you want a lush lawn you should fertilize in the fall because the nutrients will go into root growth. Another problem is the broadcast lawn spreaders. When people use them, a lot of fertilizer goes on to hard surfaces like sidewalks and roads. One of the things I liked about Minnesota's law is that it required people to sweep up after fertilizing. Personally, if you want to ban something it should be broadcast spreaders, especially the ones that do not have the edge bar that allows you to control where the fertilizer goes.

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POST #7: How do I quantitatively compare the water quality benefits gained by restoring streambanks versus maintaining a certain width of riparian buffer? We would like to provide developers with the option of restoring streambanks in exchange for reducing riparian buffer widths.

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This question was excerpted from the following posting:

Has anyone dealt with incentives and how to quantify them in reference to stream restoration practices with stream buffer widths regulations? How do we quantify comparable improvements to water quality: stream restoration vs. stream buffer widths? We are working on a new streamside buffer ordinance. Inside the city and in the urban growth boundary we have several streams that have extensive stream bank problems: as a result of urban development and/or animal problems (man and cow). For new development and re-development, we want to give incentives for the new developers to do stream bank restoration, revegetation or habitat improvements using approved techniques. We think that we could allow the decrease of buffer widths in some areas as a trade off for 'stream restoration' making sure we always have a minimum buffer that could not be disturbed. We are struggling with quantifying this. Some of these streams have more under-cuttings and eroding banks than stable areas. We think we could reduce the soil loss in these streams a great deal with restoration practices. We want to be able to say: "If the developer repairs 2,000 feet of stream (with an approved bio-engineering plan) we will allow the developer to reduce the required undisturbed buffer from 50 feet on both sides to 25 feet on both sides (at a minimum) along a selective 200 feet of development." But we do not want to open it up to the developer to reduce the required 50 feet to 25 feet along the entire area while only doing a small restoration project; this would not be equal. How do we compare water quality benefits with the reduction of stream buffer widths with restoration projects?

RESPONSE #7a: Excellent question. We adopted a stream buffer ordinance about three years ago, and some of the same issues came up. I personally don't think you can really trade "width" for "restoration." This is mostly because the two issues you're discussing, water quality and stream erosion, are related but distinct. I'd encourage you to begin with each objective as distinct, and carefully think through the process issues that are involved. For stream erosion, undercut banks, etc, you need to adopt a minimum buffer width that creates a "buffer" in the erosion-danger zone. The buffer does three things: (1) preserves the trees or grass roots that help stabilize the soils (2) prevents livestock, construction, other disturbances from trampling them, and (3) gives you room for "error" when the stream does begin eroding. I'd encourage you to look for a "stream geomorphologist" to assist in this. The width you need would be based on geologic factors unique to your area, including the depth of future down-cut possible (areas with deep soils have a great potential down-cutting, leaving ever wider bank erosion zones). I doubt you'll get a perfect answer, but for us it turned out to be about 100' both sides of larger creeks to give us room against bank erosion. Once established, this width really isn't tradable. You might be able to make some adjustment dependent on stream geometry (outside of bends will have a higher potential for future erosion than the inside of bends, large bluffs may need more buffer if they are potentially unstable, etc). Be careful, though, because landowners will push the envelope. Better to push back hard against encroachments.

If this is an urban watershed, then you also have to deal with the hydrologic changes that drive stream degradation. In some cases, it may be too late to head off the dramatic changes in driving forces. This is far more complex than just controlling the 100-, 10- or 2- year storms. Start by reading the Federal Interagency Stream Restoration Manual at the link below. I'd focus on reading Chapter 2 if that's all you have time for in the beginning-- www.ntis.gov/products/bestsellers/stream-corridor.asp?loc=4-2-0.

On water quality, it all really depends on the orientation of the smaller tributaries and overland flow into the area. If 90 percent of the drainage is brought to the stream via pipes rather than through the buffer, then you really aren't getting much water treatment benefit from the buffer anyway; this doesn't mean buffers aren't worthwhile, it just means you have to be honest about what services they are performing, and what services they aren't.

If instead you bring a lot of water to a narrow buffer, you might be overwhelming the ability of the buffer to restore sheet flow. In that case, you might get rills and gulleys formed that diminish the water quality benefit. You really need to view the treatment that occurs within the buffer as a volume-based process, and consider how the water gets there, how much residence time it will have, flow length, degree of concentration, etc.

Lastly, one of the goals of restoration is usually riparian ecology. This is a very worthwhile goal, but it's not exactly the same as water quality. To some degree, you can trade width for quality of buffer on the ecology front, though there are some hard and fast minimums: you need a minimum corridor width for wildlife to travel, you must maintain continuity (breaks in the buffer limit wildlife migration), and the narrower the buffer, the more influence edge species will have. This kind of trade-off can best be handled by consulting with local ecologists, who will know what key species or groups of species must be considered.

I view these three separate needs as overlays. Add floodplains to the mix and you have a fourth layer. Some of the layers have more flexibility than others, but each has some hard minimums. When trading around on areas, you have to think through the 4 individually, and then imagine the best composite. I doubt you can simplify this down as much as you would want to. Perhaps being hard-nosed on a standard buffer width is the better option. You can use some other vehicle to provide incentives to restoration. By the way, I think a 50-foot buffer is the barest minimum, except for itty-bitty drainages (20 acres or less). I'd be very nervous about dropping any buffer down to 25 feet.

Also, I'm not convinced that "bio-engineering" is a panacea. If you have a stream that is down-cutting, no amount of toe-stabilization will head off the future widening that is bound to happen. You would have to use grade control strategies for that. Streams can increase in width by dramatic amounts (I've heard "four times" to "10 times" their original width being quoted, not sure I know of valid studies on this though). If your goal is to eliminate sediment in stream by reducing stream bank erosion, you need to have a qualified stream geomorphologist on board. If you'd like some hints on finding one, contact me off-list.

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POST #8: You are invited to a free webcast from EPA's Watershed Academy on Implementing TMDLs and Trading Through the National Estuary Program, Feb. 21, 2007, 1-3 p.m. Eastern.

Session Description: The National Estuary Program (NEP), established as part of the 1987 amendments to the Clean Water Act, is proud to be celebrating its 20th anniversary of protecting and restoring estuaries of national significance. The program promotes comprehensive planning efforts and actions to help protect 28 designated estuaries deemed to be threatened by pollution, development, or overuse. The NEP uses a proven approach of: focusing on specific watersheds, using science to inform decision-making, emphasizing collaborative problem solving, and involving the public. This webcast will provide an overview of the NEP and will show how it implements another key Clean Water Act program-the Total Maximum Daily Load (TMDL) program. It will include a case study of the Long Island Sound NEP, which has successfully used its Comprehensive Conservation and Management Plan (CCMP) as the basis for developing a TMDL. The webcast will also discuss the innovative trading program used in Long Island Sound that is reducing nitrogen loads faster and more cost effectively. For more information, visit www.epa.gov/watershedacademy.

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