Grinder Pumps - Sewer Services
Waterfront lots, open space design, and high water table problemsovercome with E/One low-pressure-sewer (LPS) system
With a population of approximately 21,000 people , Hamburg Township is one of Southeast Michigan's fastest growing communities -- a suburban community with a rural recreational atmosphere, including a chain of lakes, several basin lakes and the Huron River. Hamburg Township's central location between the large cities of Lansing, Ann Arbor, and Detroit provides residents with a convenient commute to work .
Approximately 10 miles of the 125-mile long Huron River traverse Hamburg Township connecting the "Chain-of-Lakes," running through Ore Lake, Strawberry Lake, Gallagher Lake, Whitewood Lake and Portage and Base Line Lakes. The inland lakes and Huron River corridor are unique because of their residential attractiveness and scenic amenities.
The Challenge: Preserving the environment without breaking the bank
While the Township's exponential growth over the past decade has brought many changes to the area, Hamburg has worked hard to preserve the rural beauty and quality of the township. Hamburg Township has many new award-winning open space design residential communities that have access to the natural environment often situated on or near waterfronts. This style of land use preserves the naturally occurring space within house lots or provides for recreation and park areas for homeowner use. Providing affordable sewer service to such developments presents unique challenges. Gravity sewer systems require the construction of deep trenches, which can be costly and disruptive to the natural environmental.
Many of the existing waterfront homes in Hamburg Township were constructed on very small lots converted from old summer cottages into year-round residences. The original on-site septic systems that could handle seasonal use proved to be inadequate for year-round usage. Water from the failing septic systems ends up directly in surrounding lakes causing water pollution with the eventual degradation of recreational use and land values. Traditional gravity sewer systems are not appropriate for small waterfront lots due to extensive and disruptive construction, lack of space, and high costs.
Hamburg Township also suffers from very high water tables in many areas. Gravity sewer systems are very susceptible to ground water infiltration. The addition of ground water to the system creates higher operation and maintenance fees for the property owners and requires increased wastewater treatment capacity.
Hamburg Township needed to find low cost sewer system alternatives that would preserve their most important quality of life characteristics, including natural open space designs and waterfront development.
The Solution: E/One LPS SystemsA group of residents on Ore Lake, the first lake at the beginning of the chain of lakes, petitioned the township in the 1980’s for a Sanitary Sewer Special Assessment District. The Special Assessment District allowed the Township to finance the cost of the sewers through bond sales. The residents repay the township over a 20-year period with the assessment being added to the tax bills.
Hamburg Township entered into an agreement with an engineering firm for the design of the sanitary sewers for the Ore Lake residents. The first design was to construct and install a gravity type sewer system and estimated costs were presented to the Township and the Ore Lake residents for their review. Upon review, concern about the high water table and the exorbitant cost of dewatering, forced officials and residents to request alternative designs for the sanitary sewer system.
Alternatives were presented and officials chose to install a low-pressure-sewer (LPS) system, which included a grinder pump station at each home. An analysis of lifetime costs in similar areas showed that a low-pressure-sewer system is more cost-effective and less destructive than a gravity sewer system. Competitive bids were solicited and Environment One Corp. (E/One), a pioneer in LPS systems since the early 1970’s, was selected as the lowest competitive bid.
How Pumps Work
The heart of the E/One LPS system is the GP 2000 grinder pump, which can be installed inside or outside the home. The grinder pump, smaller than a washing machine, grinds wastewater into a fine slurry and pumps it under pressure in small diameter pipes directly into a sanitary sewer collection system to be treated at a wastewater treatment plant.
GP-2010 Grinder Pump
An LPS system has multiple benefits but cost-effectiveness is a major advantage. Installation requires only a shallow trench and small 2- to 4-inch diameter piping. Unlike conventional gravity central sewers, which use 24-inch pipe and require deep excavation, the E/One LPS is not destructive to the landscape's natural or built features and requires less maintenance. Since gravity is replaced by the power of the pump, sewer systems need not run downhill nor require large-diameter pipes, deep trenches, multiple booster stations — or their associated costs.
In addition, the cost of installing an LPS system can be back-end loaded. The up-front cost does not have to be extended until the building site is actually sold. The biggest outlay -- perhaps 40-to-50 percent of the cost – can be deferred until a lot is sold. In some cases land developers using an LPS system have realizedsavings up to 80-90 percent in up-front costs.
The Results
The E/One LPS system has provided the Hamburg Township with continued cost savings over other types of sewer systems. LPS sewer lines are installed using a method called directional boring (or drilling). A hole is dug at the entrance point of the line and the exit point of the line. The small diameter sewer line is then pulled underground eliminating the need to cut large open trenches required for a gravity system. The contractor does not have the problem of dewatering trenches either. All of these things add up to an overall cost savings to both the Township and the property owners.
As Hamburg Township continued to grow, the use of E/One grinder pump stations and low pressure sanitary sewer collection systems has helped developers to improve their property while maintaining the integrity of the land and surrounding bodies of water. The LPS system eliminates the area needed on lots for large on-site septic systems required under the Michigan health codes, allowing residents to utilize more of their property. The relative small size of the E/One grinder pump station also lends itself well to the smaller lot size, as it can be located almost anywhere on the property to serve the home.
GP-2014 - Commercial Grinder Pump
In our experience, the E/One grinder pump has provided service regardless of the size, shape, or contour of the property. Property owners like the fact that the grinder pump is easily camouflaged by planting flowers and other landscape plants around the lid providing a little aesthetic appeal.
The LPS system has allowed development in areas that were previously unavailable due to topography. The E/One LPS system adapts to almost any type of terrain, even steep slopes. The grinders can even pump the wastewater uphill to the sewer collection system, a feat that is impossible with gravity style sewer systems. And because LPS piping is a closed system, installed near the surface, ground water infiltration into the sewer collection system is eliminated, resulting in lower costs for operation and maintenance.
Hamburg Township has expanded its use of E/One grinder pumps based on the standard of quality, cost, and the warranty of the equipment.
The Environment One Corporation has continued to work with the Township to negotiate pricing based upon the large quantities of grinder pumps purchased on an annual basis by the township. This in turn reduces the cost of providing sanitary sewer service to our residents. E/One also provides the Township with a 5-year warranty from the date of installation for each grinder pump station. The quality of the equipment, combined with the warranty provides additional operation and maintenance (O&M) savings, which we can pass on directly to our customers. The quarterly O&M fee to home owners has not increased since the Township built the first sewer district over 15 years ago.
Future plans
At this time 2,100 E/One pumps are in use, representing ten percent of the population of the Hamburg Township. Property owners around Rush Lake, Oneida Lake, and the Huron River have recently petitioned the Township to construct a low pressure sewer system including installation of E/One grinder pump stations to serve their homes. Over the next six to nine months the Township will install an additional 300-plus E/One grinder pump stations pushing the total number of pumps in use to around 2,500.
In addition, planned developments located within Hamburg Township will add an additional 400-plus E/One grinder pumps over the next 2-3 year period.
As the Hamburg Township continues to grow into the 21 st century, E/One LPS sewer systems will continue to play a major part in cutting installation and O&M costs, reducing pollution, and preserving the natural beauty of Southeast Michigan development.
For more information on E-One Grinder Pumps, click here.