Dr. Robert Traver, Director of the Villanova Urban Stormwater Partnership (VUSP) and Professor in the Department of Civil and Environmental Engineering at Villanova University recently sent out an update on the activities of the VUSP that we thought we would share. Dr . Traver writes:

Hello all!  It has been a wild ride this year, and my apologies for taking so long to update everyone.   This is to let you know our most recent year end report is available on the VUSP website.

PaSWM - Well the symposium exceeded our wildest dreams.  We received great reviews, and the attendance was only slightly off from the past - approximately 300.  I forgot how energy it takes, but it is simply a great event and thanks for your participation.  We had great speakers and great participants!

Stormwater Control Measure Research -I think overall the work is going well.  Our latest research update is available from the VUSP website.  Our only challenge is to focus on a subset of what is possible.  As of last count, we have MANY rain gardens, multiple porous surfaces, two green roofs, an infiltration trench, a historic seepage pit, a dry and wet detention pond, rain barrels, a SWW and are building a bio swale.  I wish we had the resources to study them all!

319  - We are continuing to focus on the Pervious Concrete and Porous Asphalt (PCPA) Site, the Bio Infiltration Rain Garden, and the In filtration Trench.  We are looking harder at the soil nutrients, and temperature effects.  Dr John Komlos is using this data to look at how long can the soil remove P before it is exhausted.  The first estimate I think is over 20 years for the top several inches.  Dr. Andrea Welker has a problem… the pollutants moving through the PCPA are so low it is hard to measure (Now that is a problem I like!)  She is concentrating on the temperature, flow, and chlorides.  We are also studying the opposite end of the spectrum that being the Infiltration Trench which is real dirty.  The contrast of the sites plus the extreme nature of the IT allows for good comparisons.  Dr. John Komlos is piggy backing on these projects with a study looking at stormwater toxicity which we are hoping will be renewed and expanded (EPA Edison) .  A critical point is all this work would not be moving forward without the student support from the 319 program.

CiCeet - We are still working on a CiCeet grant from NOAA that is allowing us to compare the results of Bio Infiltration/Bioretention sites from Univ. of Maryland and NC State.  The results so far are dramatic.  When viewing the error band for peak flows the results are scattered (though all reduced) but we are amazed at the repeatability and narrow error bands when we simply look at Volume in and out.  I have to bite my tongue; we are even able to relate the performance to a reduction of the NRCS Curve number.  We have submitted a publication to ES&T, which we hope to receive comments on soon, and I put a few of the graphs in the yearend report.  This grant unfortunately dies out in Fall 2010, and we are hoping to continue this work through other sources.  Through this grant, Ryan Lee is working on a more physics based approach to simulating the hydraulics of a rain garden.  All of this work is founded on the continuing 319 data collection efforts.

319 & ET Dr Wadzuk is about finished redesign of the stormwater wetlands using a GGII grant. We hope construction starts soon!  It will be much more circuitous then before with a series of gates to extend the contact time.  I am curious how much better it will work then my original design using a sketch.  The field has advanced!  We build two new rain gardens and soon a bio  swale using an older GGII grant, and as of now we have 11 rain gardens on campus, and are hoping to have four of them instrumented (need four more students!).  Dr Wadzuk is leading the charge, on our ET grant, looking at Green Roofs, Bio Retention/infiltration and a mini stormwater wetland.  The first Thesis on the green roof ET will be out soon.

TVSSI- William Penn - We continue to partner with temple, and this time we are focusing on monitoring and the longevity or performance of Green Infrastructure systems.  We are looking at designing a simple measuring device for rain gardens to help municipality know how they are working.  Dr. Andrea Welker is looking to work with a student to visit many older or recent BMPS (SCMS) and check their status as an effort to educate the work force on ho w they do after construction!

ARRA -Rain barrels and Rain Gardens - Well we almost finished our Rain Barrels and Rain gardens ARRA project, we are at the 99% mark but halted by the snow.  I believe we installed 28 Barrels and 6 new rain gardens on campus.  Note this is not a research project, but one to reduce NPS pollution and to be a good neighbor ( and some employment).  I am tempted to throw in a pressure transducer in the barrels, but I think I will wait till I find an undergraduate to work on it for a course.  I see many potential projects on campus, but one step at a time.

EPA III Green Highways  — EPA Stormwater Regs - We have met and given sem inars at EPA III on Stormwater Green Infrastructure, and are looking at how  we can aid and get more involved with the green highways program (I have been contacted to conduct a free webinar through EPA on the subject in April).  We continue to see this as a great need, and many of our projects translate well.  I also presented testimony in DC to EPA regarding proposed national stormwater regulations.

Villanova Center for the Advancement of Sustainability in Engineering.  Well, one last thing.  The College of Engineering has created VCASE in order to bring together say Energy and Stormwater, etc.  The College has granted me a course release for VUSP and to create the VCASE.  So I am now Director Squared.  This organization will allow us to diversify and I hope bring more resources to our research.

Rob

Robert G. Traver, Ph.D., PE, D.WRE

Visit VUSP on the web.

admin General bioretention, BMPs, economic stimulus, federal stormwater regulations, green highways, green infrastructure, green roofs, infiltration, Nonpoint source pollution, pervious pavement, porous pavement, rain barrels, rain garden, stormwater legislation

As previously noted in our September posts, PA DEP has convened a BMP Manual Revision Committee. In their notification to attendees, they noted that

… recommended updates may include edits to existing portions, complete omissions, or additions of new material.  All changes much be justified through acceptable principles of engineering or science.  If unable, to do so, subgroups may bring new ideas before the bigger committee for consideration and feedback.

Following is PA DEPs statement on the focus of this  Sub-Group, as presented at the first Committee Meeting:

The BMP Manual needs more emphasis on Volume Reduction Computations for vegetated systems such as swales, rain gardens, green roofs, constructed wetlands, naturalized basin, soil amendments, landscape restoration, floodplain restoration, etc.

Evapotranspiration accounts for more than half of the annual water budget in natural areas.  However, it is seldomly included in SWM designs or computations.  Can the  group develop an acceptable method or model that takes ET and the other benefits of vegetated systems into account.  (Also see Subgroup Topic B)

• Does the BMP manual provide sufficient info for native plants and their incorporation into vegetated BMPs?   Where are the gaps and how can they be addressed?   Should the planting recommendations for rain gardens and other vegetated BMPs be modified?  (i.e. plant density, spacing, species selection, etc.)  How and why?
• How can the BMP Manual be updated, as a whole, to provide a better focus on green infrastructure?  Are there areas that conflict with Green Infrastructure initiatives?
• What additional incentives should be incorporated into the manual to encourage green infrastructure and vegetated BMPs?
• What additional credits (or modification to existing credits) should be incorporated in the manual for “green” and non-structural BMPs?

Vegetated swales vs. underground piping.  Intuitively, we know that runoff traveling across a stable and vegetated channel has more opportunity for volume control and water quality treatment than with piping.  Since there are no incentives for volume reduction, practitioners seldomly make the effort to provide vegetated swales unless they are trying to meet water quality protection guidelines.

• What specific volume reduction criteria or other credits can the subgroup develop for vegetated swales?  (above and beyond the credit that is given with check dams)
• What has been done in other states and can be utilized in PA?  (i.e. Washington State, Delaware, etc.)

Some vegetated BMPs require a different modeling approach.  For instance, Green Roofs.   CN methodology has been utilized for Green Roofs, but this is more of a “bastardization” of the CN method since green roofs do not behave like natural ground.   (e.g., S, Ia, etc.)   There has been a lot of research done with green roofs in recent years which hopefully can shed light on this issue and provide designers with an approach for computing both volume and peak attenuation - as well as water quality.

admin BMP Manual Revision BMPs, constructed wetlands, floodplain restoration, green infrastructure, green roofs, naturalized basins, non-structural BMPs, PA BMP Manual, rain gardens, vegetated swales, volume control