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Bergen County Utilities Authority Little Ferry, New Jersey. Rain Derived Infiltration/Inflow Reduction and Sanitary Sewer Overflow Elimination Program Tenafly Borough Presented by: Leonard A. Faiola, PE Remington, Vernick & Arango Engineers April 5, 2011. Introduction.
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Bergen County Utilities AuthorityLittle Ferry, New Jersey Rain Derived Infiltration/Inflow Reduction and Sanitary Sewer Overflow Elimination Program Tenafly Borough Presented by: Leonard A. Faiola, PE Remington, Vernick & Arango Engineers April 5, 2011
Introduction • BCUA is responsible for its Interceptor Sewers and Treatment Facilities, not municipal sewers. So why is BCUA undertaking this project? • Wet weather flows at the BCUA Little Ferry Water Pollution Control Facility (WPCF) are a problem chiefly due to municipal sewers Rain Derived Infiltration/Inflow (RDI/I). • Sanitary Sewer Overflows (SSOs) from manholes and into basements are prohibited, although are reported by municipalities • Without action NJDEP could prohibit new sewer connections and new land development projects in the BCUA District.
Introduction • On April 15 and 16, 2007, New Jersey experienced a Nor'easter that brought 5 - 12 inches or more of rain. • Storm events as recently as March 2011 also resulted in substantial rainfall and runoff. • These storms activated Rain Derived Infiltration / Inflow. • Caused sewer back-ups into basements, manhole overflows, pump station overload, and other serious problems in BCUA member municipalities. • Caused municipal sewers to surcharge. • Caused a partial by-pass of the BCUA WPCF in Little Ferry into the Hackensack River
NJDEP Requirements • NJDEP required that the BCUA provide assurance that RDI/I will be reduced in order for it to approve the BCUA Wastewater Management Plan (WMP) • WMP approval is required to allow for future land development projects and associated sewer connections in BCUA member municipalities. • An amendment to the BCUA’s WMP incorporating various development is currently being processed by the NJDEP.
Definitions • Rain Derived Infiltration- The leakage of ground and storm water into the sanitary sewer system through defects in the piping and manholes during wet weather. • Inflow- The entrance of storm water into the sewer system from roof leaders, sump pumps, area drains, foundation drains, manhole covers, storm sewer cross connections, leaking water mains and non-contact cooling water.
Inflow/Infiltration Sources into Municipal Sanitary Sewers MUNICIPAL SANITARY SEWER MAIN
Excessive RDI/I • Consequences: • Sanitary Sewer Overflows (SSOs) that include sewage backups into houses and businesses • Damage to property • Pollution of local stream corridors, Hackensack River and its tributaries • Clean-up costs to property owners & member municipalities • Health & safety hazards • Economic hardships • If not reduced- enforcement including fines, prohibitive costs to enlarge municipal collection system and BCUA WPCF in Little Ferry
USEPA Report • USEPA 1990 Report to Congress on its Study Findings for RDI/I • Noted it is important to address the entire area of the sewer system including public and private portion • Recommended municipal programs to assist homeowners to pay for repairs of Private Building Service Connections (PBSCs) and prohibited connections
USEPA Case Studies • Studies across the country show the following: • Private Building Service Connections (PBSC) and prohibited connections are major sources of RDI/I 40 to 80%. • Municipal sanitary sewers are more prone to RDI/I than interceptor sewers
Evaluation Findings • BCUA has conducted a comprehensive engineering study and found that Rain Derived Infiltration/Inflow account for: • On an annual average, approximately 30 MGD of RDI/I is entering the BCUA system from its member municipalities • Peak rate approximately 138 MGD over dry weather for the storm analyzed • As evidenced by the Nor'easter and the BCUA evaluation, the member municipalities have been unsuccessful in removing RDI/I alone.
BCUA Approach • The BCUA has developed a comprehensive plan to: • Reduce excessive RDI/I • Eliminate SSOs • Assure capacity in the BCUA Interceptor sewer and treatment facilities • Assure adequate and future capacity of yourMunicipal sanitary collection systems • Complete without costly BCUA WPCF or additional municipal sewer construction
BCUA’s Role The BCUA constructed interceptor sewers and a WPCF in Little Ferry to replace failing individual municipal sewage treatment plants in the 1950’s due to serious water pollution in Overpeck Creek and the Hackensack River The BCUA will again assist its member municipalities, such as Tenafly Borough, to collectively accomplish what they could not do individually.
Reduction Goal A goal of 30% reduction in RDI/I over a 20-year period is reasonable and attainable based on tasks and established case studies.
Initial Steps • The following outlines the initial steps required to achieve this goal: • Presentation at municipal Mayor and Council meetings to obtain acceptance and cooperation • Approval of the local municipal government to undertake corrective work within their municipality • Execution of the Agreement with municipality • Approval/agreements with impacted property owners for access to perform property/basement assessment and where required install corrective measures
Proposed Tasks • The following subsequent tasks are proposed by BCUA: • Engineers will request voluntary permission of property owners to enter their property to conduct inspection of basement plumbing and home exterior to locate sources of RDI/I • Identify RDI/I connections to the sanitary sewer system • Identify leaking PBSCs through internal CCTV inspection. • Repair/replace leaking PBSCs at no direct cost to property owners or the municipality
Proposed Tasks- (continued) • BCUA shall redirect sump pumps out of the municipality’s sanitary sewer
Proposed Tasks- (continued) • BCUA shall assist to redirect roof leaders out of the Municipality’s Sanitary Sewer
Proposed Tasks- (continued) • BCUA shall assist to redirect foundation drains out of the Municipality’s Sanitary Sewer
Proposed Tasks-(continued) Where necessary, install a storm water sewer in the municipal right-of-way for sump pump discharge from homes Repair manhole leaks and adjacent pipe shears of municipal owned sewers Repair municipal owned sewer mains by grouting, lining, or replacement All at no direct cost to the homeowner or the municipality.
BCUA Repairs • BCUA will enter into an agreement with Member Municipalities to make the necessary repairs to reduce RDI/I where sewer system leaks on municipal rights-of-way are located. • The BCUA will also enter into a agreement, on a voluntary basis, with private property owners for repairs to be made.
Actions • The BCUA has/is conducting the following: • Implementing a Public Information Program to facilitate voluntary compliance including a rain barrel sales initiative as an incentive to disconnect roof leaders from sanitary sewers.
Actions-continued • Prioritized Tenafly Borough Meter Basin Areas based on previous RDI/I studies. • Identified sources of RDI/I within the Tenafly Borough through previous RDI/I studies. • BCUA to publicly bid and contract for the necessary repairs/rehabilitation both on municipal right-of-ways and within private properties.
Findings to Date • Total estimated RDI/I is 825,000 gpd based on previous studies • This is approximately 43% of total sanitary sewer flow • Manholes located in low, flood prone areas contribute to excessive Inflow • There are numerous locations of sewer crossings at streams, many of these are siphons
Tentative Schedule • Tenafly Borough • Mar/April 2011- Public Meeting with Mayor/Council • April/May 2011- Execution of Agreement w/Municipality • May/July 2011 - Obtain property owner permission to conduct basement plumbing assessment • May/Dec 2011 - Conduct street sewer and door to door home field investigations • Jan 2012 - Report on findings • Feb/June 2012 - Obtain agreement w/property owners to conduct corrective work • July 2012 - Initiate remediation of RDI/I sources
In Summary • The project objective is to reduce RDI/I by a goal of 30% which in turn will: • Help reduce sewage related costs • Improve the health and safety of residents by helping to eliminate sewer back-ups into basements • Improve municipal ratable base by ensuring sewer capacity for future land development projects • Forego costly sewer and plant expansion for rate payers • Improve the local water environment by helping to reduce manhole overflows and plant bypasses
In Summary-continued • The project objectives can be achieved by: • Providing a framework for the municipalities to do what they cannot do by themselves • Focusing on repairing or replacing leaking building laterals • Focusing on disconnecting prohibited connections such as sump pumps and roof drains • Focusing on manhole repairs and adjacent pipe shears
Questions & Answers “Any Questions?”