River News - January, 2017
Oars and Paddles Winter Art Show
February 25 - March 4 at the Shattuck Gallery
Our fourth annual Winter Art Show will take place during the week of February 25 - March 4 at the Dedee Shattuck Gallery in Westport. This year, our contributing artists decided to try something new: instead of painting and decorating lobster buoys, to transform old oars and paddles into works of art. Over 40 old oars were donated.
This event is a fun distraction from the winter doldrums, and also an important fundraiser for WRWA. The silent auction will take place on Saturday, March 4, 1 to 5 p.m., with the reception from 5 to 7.
Volunteers are welcome for two-hour time slots during the week of the show, greeting guests and managing the gallery show. For a preview of the silent auction, go to our web page:
||Learn how to paint this iconic Westport Scene by Barbara Healy
Brushes and Brews February 25
Enjoy some beer from Buzzards Bay Brewing, and take an art lesson from local artists Pam Clarkson and Barbara Healy at the Shattuck Gallery on February 25,
5 to 7 p.m. The fee is $35, or become a new WRWA member for $50 and get in for no additional charge. Fee covers the cost of all materials, food and refreshments.
Space is limited to 15.
For info, to sign up, email Steve at
. Last year's participants had a blast.
We hope to see you in February!
Do frequent septic system pump-outs
reduce watershed nitrogen loading?
Dr. Joe Costa
As more municipalities and residents come to appreciate the fact that groundwater discharges of nitrogen from septic systems are degrading water quality and living resources in their estuary, we receive this question from time to time.
The Massachusetts Department of Environmental Protection recommends (and we agree) that septic systems should be pumped out every three years to prevent sludge and grease from accumulating in the septic tank to such a degree that it overflows into, and clogs, the leaching field. Replacing a clogged leaching field can cost a homeowner many thousands of dollars. We have long recognized that pumping out the contents of a septic tank also removes some nitrogen that might otherwise discharge to groundwater and eventually reach our estuaries. If this is true, some have asked, would pumping out a septic system annually further help reduce nitrogen to coastal waters?
Intuitively it would seem true that there would be at least a small benefit from frequent pumpout because you are diverting some volume of wastewater from reaching groundwater. If this assumption is true, perhaps the more important questions are "How large is the benefit?" and "Is this a cost effective strategy?" There are a number of assumptions that need to be made to more precisely answer these questions.
First, while it is true that the total nitrogen content of septage (what is pumped out of septic systems) can be quite high, the reality is that septic system sludge (which contains a lot of nitrogen) keeps accumulating in thickness on the bottom of the tank until it is pumped out. However, this nitrogen in the sludge component of septage may be quite refractory; that is, it does not degrade easily.
Many thanks to Dr. Joe Costa, Executive Director of the Buzzards Bay National Estuary Program (BBNEP) for allowing us to republish his article. For more information on the BBNEP visit their website: http://buzzardsbay.org/
Therefore, from a conservative management point of view, we would assume that when a septic tank is pumped out, we are losing only the nitrogen that would have flowed out during the time an emptied 1500 gallon tank is refilling with household sewage.
To contradict this assumption, we would have to find a study that shows nitrogen discharge was lower for weeks and months after the system was pumped out because of increased performance. However, the opposite may be true. For example, the point is sometimes made, as in this technical study by Bounds, 1997 (1) , that the sludge layer provides an important environment for degradation and mineralization of waste, and too frequent pumpouts may adversely affect septic system performance. However, for the purpose of the analysis presented here, we will assume that little denitrification occurs in septic tanks, irrespective of the depth of the sludge layer.
Therefore, using the assumption that septic system nitrogen mineralization and denitrification rate is not affected by pumpout frequency, then, with 50-gpd per person flows and 2-person occupancy (approximate averages for our area), pumping out a septic tank could suspend discharge from the leach field for 15 days. This is 4.1% (15/365) reduction of annual flow and nitrogen discharge.
The Commonwealth of Massachusetts recommends pumpouts every 3 years to protect the leaching field from clogging. Using the above assumptions, this is the equivalent of a 1.4% per capita annual nitrogen reduction. If the homeowner pumped every year instead, he would reduce his nitrogen another 2.7% over normal recommended maintenance pumpout frequency.
In a watershed where 50% of the load is from septic systems, that would equate to a 1.4% annual reduction in total loading. This helps a little in nitrogen management, but it would not be discernible in the water quality data from the estuary because such a decline would be masked by the normal annual variation in water quality that results form changes in summertime precipitation and other variability in weather.
Are frequent septic pumpouts a cost effective strategy compared to sewering, for example? Consider a watershed with 1000 septic systems. If everyone followed the state's guidelines, over a 20-year period, each home would have 7 pumpouts. If pumpouts cost an average of $250, over the twenty-year period, the homeowners would spend $1.75 million. If they pumped every year instead, these same homeowners would pay $5.00 million (this ignores rising costs due to inflation).
What would the extra $3.25 million over 20 years get you? With a 1000 homes with a 2 person occupancy and 5.9 lb per capita assumed watershed loading, the 2.7% annual load reduction would be 319 pounds of nitrogen in the watershed each year.
In the above example, we chose a 20-year period to make possible a comparison to sewer betterments. Some recent 20-year sewer betterments, together with other homeowner costs have been as high as$30,000 per home. With $500 per year sewer fees, over twenty years a homeowner will pay an additional $10,000 (this is a minimum based on the current rates; sewer fees tend to rise with inflation). Therefore, at a $40,000 per homeowner cost, the $3.5 million spent for extra pumpouts would completely pay for sewering 88 homes (including their annual sewer fees). Eighty-eight homes (with two-person occupancy) contribute 1,038 pounds of nitrogen per year. Thus, from a nitrogen management point of view, it would be three times more cost effective to sewer a small number of homes than to pump-out more frequently a large number of septic systems.
Of course, there are all sorts of limitations to this analysis, and many watershed-specific factor come into play. Septic systems need to be maintained in perpetuity, sewer betterments go away after 20 years, and you are left only with maintenance costs. (Of course after 20 or 30 years a homeowner may have to replace or upgrade a septic system and municipalities may have to replace or upgrade their wastewater facility starting a new round of costs.) Another issue is the location of the wastewater facility. If the septic system septage goes to a sewage treatment plant in the same watershed, the benefits may not be as great. Similarly, sewering homes and connecting to a treatment plant in the same watershed would diminish the effectiveness of that strategy. In those situations the treatment plant's performance in removing nitrogen would be an important consideration in the analysis. In addition, the effectiveness of nitrogen removal by sewering (or pumpout frequency for that matter) also depends on whether the septic systems considered in the analysis are in the upper watershed where there is some natural attenuation (loss) of nitrogen, or in the lower watershed where losses are less likely to occur.
Sewering is not the only possible way funds for more frequent pumpouts could be utilized. Another potential use of $3.5 million dollars of private funds spent on extra pumpouts could be used to pay for infrastructure upgrades to a wastewater plant to improve its capacity to remove nitrogen. Again this is site specific solution, but such upgrades could potentially eliminate the equivalent of many hundreds of homes if the plant discharges 10 ppm nitrogen or higher.
Based on the above analysis (and given the stated assumptions), the BBNEP would not recommend annual septic system pumpouts as a cost effective general strategy to manage nitrogen.
Comments about this article should be directed to
(1) Bounds, T.R., " Design and Performance of Septic Tanks," Site Characterization and Design of Onsite Septic Systems ASTM STP 901, M.S. Bedinger, A.I. Johnson, and J.S. Fleming, Eds., American Society for Testing Materials, Philadelphia, 1997.
Merit Scholarship Funds
Available for Local Students
The Westport River Watershed Alliance is pleased to offer a $1,000 scholarship opportunity for graduating high school seniors in the Westport River watershed: Fall River, Dartmouth, Freetown, Westport, Little Compton, and Tiverton. The award was made possible by the generosity of the late Margot C. Boote and Bill Heath, in memory of his parents Ruth and Bill Heath.
The Watershed Alliance is seeking applicants with an interest in pursuing the
environmental sciences, but high achieving students with other academic interests will be considered.
The merit award applications are available on the WRWA website: http://westportwatershed.org/news-events/2012-merit-scholarship/ or by calling the WRWA office at 508-636-3016. Guidance departments in local high schools have applications on file. All applications are due in the office no later than April 1, 2017. The Alliance has a proud record of environmental stewardship. This merit award offers an opportunity to honor students who have demonstrated interest in protecting the environment.
Mark Bertness will present
"How will salt marsh die-off and
sea level rise get along?"
Professor Mark Bertness from the Department of Ecology and Evolutionary Biology at Brown University will give a talk on the subject of our already deteriorating salt marshes, and what the consequences of sea level rise might be on them. It will take place on Thursday, March 2 at 7 pm in the Manton Room the Westport Public Library. Admission is free.
Much of Professor Bertness' studies has been on salt marshes, particularly from Cape Cod to Long Island Sound. His findings have found a correlation between depletion of
predator species like blue crabs and the prevalence of excess numbers of purple marsh crab, which feed on the roots of the cord grass that hold the salt marshes together.
|Professor Mark Bertness of Brown University has conducted extensive research implicating the loss of predators of the purple marsh crab in the degradation of our salt marshes.
Registration is Open for WRWA's Summer Coastal Ecology Program
The Westport River Watershed Alliance is again offering a variety of fun, hands-on summer science program for kids ages 3-16.
The Coastal Explorers
*Monday- Friday 9 a.m. to 1 p.m.
*Weeks of July 11-15 & July 25-29.
Children discover marine life, create eco-crafts, learn about coastal habitats and enjoy games on the beach. The program fee is $160 for WRWA members, $200 for non-members.
*Monday-Friday 9 a.m. to 1 p.m.
*Weeks of July 18-22 and August 8-12.
This program delves deeper into understanding our environment by learning about food chains and the creatures that make up our watershed ecosystem. Participants will head out on WRWA's skiff to explore the Westport River. The cost is $180 for members and $220 for non-members.
*Monday through Thursday 9 a.m. to 2 p.m., Friday 9 a.m. to 3 p.m.
*Week of August 1-5.
Participants learn about the ecology of the Westport River, visit coastal
habitats and spend three days paddling on the Westport River. The kayaking/paddle
boarding portion of the program is led by certified instructors from Osprey Sea Kayak
Adventures, and includes all equipment and instruction. The fee is $360 for members and $400 for non-members. Register online at:
or call 508-636-3016
Chris Smither and Dar Williams
Will Headline 2017 Summer Concert * July 15
Tickets on Sale Now from WRWA and Narrows
Mark your calendar for our annual summer concert at the Westport Rivers Vineyard. Dar Williams and Chris Smither will be performing on Saturday, July 15, 2017 at 6 p.m. These well-known and profoundly talented singer-songwriters will be on-stage on the beautiful Westport Rivers landscape for an outdoor evening concert to benefit the Watershed Alliance.
Like last summer's very successful Tom Rush show, this year's concert is co-presented with The Narrows Center for the Arts and sponsored in part by Westport Rivers and Buzzards Bay Brewing.
Tickets are $40 for WRWA members, $50 for non-members, and will be $60 the day of the show. Don't wait too long-last year's show was a sell out, with over 600 guests enjoying the great music and pastoral setting on a beautiful summer evening.
Get tickets on the Narrows website at
, and at the WRWA office & website
or by phone 508-636-3016.
River Center Update
We will be appearing before the Board of Health to present our innovative plans for waste water treatment and disposal in February.
On February 9th, we will be hosting a meeting with Head neighbors to show our latest plans and report on River Center progress at 7 pm at the Westport Public Library.
Still Time to Get Your 2017 Calendar
WRWA is happy to present the 2017 photo calendar. The beautiful photos taken within the Westport River Watershed were provided by contest winners Mark Goulding, Greg Stone, Amelia Tripp, Barry French, Betsy Szel, Laurie Wenham, Laurie Marinone, and David Cole.
The calendar has accurate tide graphs for the entire year and is on sale for $20.
Photo Calendars are available at WRWA headquarters, on line at www.westportwatershed.org,and at Lees Market, Partners Village Store, Country Woolens and AS Deams.
Save Us Your Lees Receipts!
Lees Market has generously continued their support of local non-profit agencies by
donating a percentage of sales back to the community. The Watershed Alliance has received over $50,000 from this program since 1989. Please save up your market
receipts and drop them off at 1151 Main Road, or mail to
Westport River Watershed Alliance
* PO Box 3427 * Westport, MA 02790. Thank you, Lees Market!