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Coles Point Wastewater Treatment Plant. Presentation to Potomac River Basin Commission Friday, October 8, 2010. Master Sewer Plan. Westmoreland County Board of Supervisors approved a Master Sewer Plan for Westmoreland circa 1996.
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Coles Point Wastewater Treatment Plant Presentation to Potomac River Basin Commission Friday, October 8, 2010
Master Sewer Plan Westmoreland County Board of Supervisors approved a Master Sewer Plan for Westmoreland circa 1996. Over 70% of our soils are not conducive to conventional septic systems.
Project Study Areas Westmoreland County BOS submitted six (6) projects to RUS for construction. The BOS was asked to prioritize due to limited funds.
Coles Point Study Area • Coles Point area was selected as the 2nd priority project. • As you saw from the previous aerial view, the creeks and Potomac River created a need for an option other than a point discharge, due to shellfish waters and excessive cost to run a discharge line to the waters of the Potomac River.
Therefore, we elected to construct a spray irrigation system to serve the areas identified in the Master Sewer Plan. The County purchased 137 acres located in Coles Point.
Project Cost • Coles Point funded by RUS for an approximate cost of $6,000,000. • The funding breakdown was approximately 74% grant and 26% low-interest loan.
Wastewater Treatment Plant • The physical plant is a Sequencing Batch Reactor (SBR) permitted at 150,000 gpd. • It is capable of being expanded for increased demand as required. • The plant was initially constructed with two 3.2 million gallon steel storage tanks (a third was just completed this year with stimulus funding.) • This provides us the capacity to hold 180 days of treated effluent.
Wastewater Treatment Plant • Our primary spray period is March thru October when we can spray an inch per day and up to 2 inches per week per field. • 228,000 gpd or 456,000 gpw • During the winter months, we can spray ½ inch per day or 1 inch per week, if the ground is not frozen or snow covered.
Spray Irrigation Fields Our spray irrigation fields total 50 acres with a 200-ft. buffer surrounding them. The fields are planted with Reed Canary Grass that provides a deep root structure and significant nutrient uptake from the effluent. (Although we have had to use commercial fertilizer due to inadequate nutrient levels for the grass.)
Spray Irrigation Fields We are required under our Nutrient Management Plan to add gypsum to the soils in the spring to decrease the sodium effect from the residents’ well-water, which has a hardening effect on the soils. We generally generate 200 round bales of hay annually.
Spray Irrigation Fields • The irrigation system is designed for the application of effluent at levels not to exceed the limits established in the permit. • During the installation of the additional storage tank, we added an additional line to the spray irrigation fields to allow us to spray two (2) fields simultaneously. • This has permitted us to reduce overtime and maximize the discharge of effluent at peak time periods.
Project Outcome • We serve 670 EDU’s in the Coles Point area. • Prior to the installation of public sewer, the area was prone to condemned shellfish waters, primarily due to failing septic systems and the subsequent runoff into the river and its tributaries. • These conditions have been significantly improved in Coles Point.
What have we learned? • We’ve added mixers to our storage tanks to reduce wait time for chlorination residual to reach permitted level. • The addition of the 2nd force main from the storage to spray fields has helped our operations. • Getting DEQ to allow us to use rain gauges to denote 1 inch volume rather than meter readings has greatly improved the farming operation. We have learned a great deal about improving this operation over the past six years.
What have we learned? • We can provide a weather forecast almost as well as the weather channel since it is critical to our operation. • We are generating increased revenues from our farming operation which help towards the O & M expenses. • Running a spray irrigation system requires a lot more diligence than a traditional discharge system. The weather creates the need for us to predicate our schedules around peak spraying periods. Hurricanes are our worst nightmare. Isabel created a situation where we could not spray during peak periods for three (3) months.
Conclusion • We believe the final product of this process enhances the environmental impact upon adjacent waters and recharges the water aquifers. • As I have told a number of visitors throughout the country who have come to see this operation, it requires a lot of skills beyond the traditional plant operations. It is at times very frustrating in dealing with regulatory bodies who do not fully appreciate the problems of these type of operations, and dealing with the many adverse weather related problems.