Saturday, December 19, 2009

We've Read the Reports, Have You?

The four WWTF are licensed to discharge 16M gal per day of improperly/incompletely treated effluent which is causing a Phosphorus loading problem in the Assabet River.

Why can’t we get an answer to the question of estimated impact of .1mgl discharge level vs. 1.0mgl during the winter months(Nov-March)?

Lowering the Assabet River level by 7.4 ft by removing the Ben Smith Dam resulting in a 25-30ft wide 1-2 ft deep river has hugh consequences including:

Loss of Public Safety water source for both towns of Stow & Maynard.

Loss of critical water source for orchards, farming, golf courses, etc.

Lowering the water table impacts ponds, wells, and perhaps the entire watershed.

Destroys year round recreational uses of canoeing, kayaking, fishing, motor boating, bird watching, etc..

Would destroy the most beautiful and scenic part of the Assabet River in exchange for a 25-30 ft wide stream with hugh “brown fields” of toxic materials quickly overgrown with loosetrife such that the river wouldn’t even be visible in 2-3 years.

Substantial negative impact on the value of the homes and property along the Assabet.

Reduction in impoundment volume(411acft =>22acft) or 95% would have enormous impact on 454 ac of impoundment area affecting wetlands, wildlife, and water recharge.

Exposing a 159 yr old toxic and trash dump site would result in hundreds of acres of “brown fields” with 5 metals exceeding RCS levels, and two, arsenic and lead which exceed acceptable landfill reuse. In addition , there is mercury, VOC’s & PCB’s, and who knows what else.

The study estimates clean up costs including sediment removal of 68kyd3 at $12M. It ignores the Sediment Study of The Assabet River estimate of 759kyd3 of sediment which could result in a cost of greater than $100,000,000!!! (759kyd3 is approximately 42,000 10 wheeler dump truckloads). Removing large amounts of material would create a lake or series of ponds or impoundment areas, Stow’s very own “Big Dig” and who would pay for it?

Errors/Omissions in the
Assabet River, MA Sediment and
Dam Removal Feasibility Study

Pg 19 Estimated Impoundment length is 2.15 mi. vs. 5.5mi length of Assabet River from Ben Smith Dam to Gleasondale Dam. This conflicts with Estimated Decrease in Average Water Surface Elevations Pg. 38 and Fig. 2 Assabet River Elevation Profile both of which clearly shows the Ben Smith Dam impacts the water level the entire 5.5 miles.

Pg 19 Impoundment Area from USGS Report is shown as 145.8AC. On Pg. 40 of the USGS Sediment Studies in the Assabet River, Central MA 2003 the Impoundment area is shown as 590,000M2 which is 19,065,597 ft2 or 454 AC an error of 3X.

Pg 10 “ Modeling limitations due to the complexity of sediment – phosphorus flux behavior meant that quantitative predictions of DO and biomass levels could NOT be made and the results of implementing different scenarios could only be qualitatively assessed.” Despite this disclaimer the study quantitatively estimated that removal of the Ben Smith Dam would improve P flux by 10%.

Pg 29 “The amount of open water increases after dam removal; from 20.8 acres to 70.2 acres.” Ridiculous. The present open water which in most areas is 200-400ft. and as broad as 600 ft. N of Crow Island is anticipated to become 25-30 ft. wide or a reduction from 70 + acres to 20 acres.

P.10 “CDM modeled six scenarios 1)…….6)reduction in phosphorus levels in WWTF discharges during the non-growing season”. Modeling just one variable lowering P levels to 1.0 mgl and .1mgl resulted in 60% reduction. Modeling a single variable of lowering P levels to .1mgl year around should be estimable and straight forward. But the study excludes the results even though it purports to have done the modeling. Elsewhere, in the study it states that “P in sediments put there during the winter can contribute over 50% of the summer P flux”. This would suggest that reducing winter P levels from 1.0 mgl to .1mgl(or a 90% reduction) could reduce winter contributions by 90% x 50% or 45 %.

The study estimates clean up costs including sediment removal of 68K yd3 @ $12.8M(Pg31&33). This does not include any legal, consultants fees, etc. The Sediment Studies estimated 580KM3(P.21) of 759K yd3 of sediment in the Ben Smith impoundment. Five of the 18 test sites in the Ben Smith impoundment showed incidences of toxicity of 50 or 100%. Toxic levels of arsenic and lead exceeded land fill levels, mercury and VOC’s were not evaluated and the study warned “incidences of toxicity presented in this report may be understated”.(Pg 39).
If the cleanup were to involve all 759Kyd3 of sediment the costs could exceed $100,000,000. The Corps of Engineers moderator commented this could be the biggest sediment removal project EVER! Larger even than the Boston Big Dig, and he doesn’t know where you could dispose of that much contaminated material.

The Bottom line - potentially $100,000,000 + of costs, annihilation of the Assabet & its surroundings and we’d be left with an even bigger impoundment!


Given that the estimate of a 10% P. Flux change by the removal of the Ben Smith Dam was based upon “phosphorus flux modeling which was too complex to handle specific combinations of dam removal, dredging and reduced levels of WWTF discharges”;(Pg 9) and given that there are numerous substantial omissions and errors in this analysis; and given that the catastrophic impacts on the Town of Stow and their residents have not been evaluated – “The removal of the Ben Smith Dam cannot be justified or recommended based upon this flawed report and the horrific impact on and costs to the town of Stow and its residents.” What is clear is the WWTF with their 16M gal/day discharge are directly responsible for the P flux problem and should be required to immediately move to a .1mgl level of discharge year round to determine if this will resolve the problem they’re creating. If after a 2-3 year “healing period” they may have to reduce their phosphorus discharge level even further to address the problem they are causing.

Anyone is free to use any or all of the above in their response.

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