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The Morrisville Municipal Authority has been reaching out to the people and municipalities in our service area to evaluate plans for building a new wastewater treatment facility (WWTF) to replace our aging and increasingly obsolete sewage treatment plant (Plant).

Mindful that the future project will be costly and complex, we are presented with the opportunity to plan, design, and build a far more efficient; cleaner; and, ultimately less-costly-to-operate facility.  A detailed feasibility study and subsequent work of engineers and economic consultants support the construction of a new facility on a new, larger, site.  The difference in the initial cost of construction between the current Morrisville location and a new site — about $80 million vs. $100 million — can be partly managed by up-front involvement of additional interested parties; grant funding not available in building at the current location; additional customer connections in the first several years of operation; and, inclusion of “green energy” technology as just one part of reduced operational expenses.  Reduction in comparative operational expenses will offset at least part of any additional debt service which might be associated with the higher initial cost.  The result is cleaner, better finished water for an increasingly larger customer base in this corner of Lower Bucks County.


The original Morrisville Sewer Plant is now over 60 years old.  It was built from 1954-1956 as a 2.4 million gallon per day (MGD) facility serving the new Morrisville sewer system.

The Plant was modified in 1964 to accept and treat sanitary sewage flow from Lower Makefield Township and Yardley Borough.  Plant capacity was increased in the early 1970’s to 5.6 MGD and again in 1986 to the current permitted treatment capacity of 7.1 MGD (with a calculated hydraulic capacity of 8.7 MGD).

Expansion of the Morrisville Plant over the years was done in stages — piecemeal — including conversion of older tanks and infrastructure.  This created two (2) separate “plants” or processing trains; one designated the “North Plant” and one designated the “South Plant.”  Both currently use what is known as a “UNOX” process, which involves supplying pure oxygen — made onsite –to closed, activated sludge, reactors.  That process was at one time considered state-of-the-art because it could treat sewage about four times faster than conventional aeration tanks.  Unfortunately, it also is an energy hog (oxygen production uses a lot of electric in compressors and controls) and it prevents easy inspection and cleaning of the treatment tanks.  It and other parts of the current Plant are functionally obsolete.


Discussions about the long-term outlook of the Morrisville Plant began to build in the last 8-10 years.  As the Plant continues to grow older, testing and regulatory expectations have become more stringent.  Morrisville’s Plant requires ever-increasing levels of maintenance to maintain effluent quality, compared to newer systems.  The basic science and engineering of wastewater treatment has not changed dramatically, but the control and efficiency of wastewater plants has.

Treatment needs also continue to advance.  In 2003, the Authority took ownership of the old Warner Industrial Park infrastructure (the Kmart warehouse area) and began to accept pre-treated leachate from Waste Management landfill operations in 2007.  Those arrangements were prescribed by the Pennsylvania Department of Environmental Protection (PaDEP).  The Authority also treats sanitary sewage from mobile home parks in Falls Township, along Old Bristol Pike.  (Any added costs related to those various operations are paid by those users).

Viewed collectively, it is clear that change or replacement of aging and increasingly obsolete infrastructure is essential.


From about 2008 till 2014 the Authority spent $5.7 million in capital repairs and improvements at the Sewer Plant (and has spent almost $4.0 million more since then).  Even with that commitment, by 2014 the North UNOX no longer was providing consistent treatment.  The reactor was taken out of service; emptied; cleaned; and, repaired as needed.  The South UNOX also was fully reconditioned immediately thereafter.

A very important note:  The proliferation of synthetic materials (“disposable” diapers, personal hygiene, and cleaning products) in the last few decades contributed dramatically to the failing efficiency of the Morrisville Plant’s UNOX reactors.  They are just one of several significant, structural, deficiencies in the current Plant driving the need for a complete rebuild.


Those circumstances led to PaDEP intervention in early 2015.  The Morrisville Authority is obligated to develop a “corrective action plan” (CAP) to address treatment issues we have identified.  That became the foundation of a frank discussion among Authority staff and professional consultants, in which the Authority was advised to consider building new treatment facilities, either at the existing location or on a new site.

The Authority directed its long-time consulting engineers, Pennoni Associates, to prepare a feasibility study, which was completed promptly in November, 2015.  It since has been supplemented, and the Authority has conducted dozens of meetings with its municipal partners, their professional consultants and staffs; is in the process of completing the mandatory “Act 537” report to the PaDEP pursuant to the Pennsylvania Sewage Facilities Act; and, has undertaken an economic study, all to evaluate the best alternative(s) for replacing the existing Sewer Plant.

Anyone interested in additional background information is welcomed to speak to the executive director, and is encouraged to attend the regular monthly meeting of the Board of Directors at 7:30 p.m. on the third (3rd) Thursday of each month.