Buffalo Sewer Authority는 버펄로 시로부터 유입되는 강우 유출과 오염물의 양을 줄이기 위한 계획을 추진한다. 뉴욕의 합류식 하수도는 환경보호국과 New York State Department of Environmental Conservation (DEC)에 승인됐다.

이 계획은 환경보호국이 Buffalo Sewer Authority에 공표한 법규 명령을 포함하고 있다. 계획 승인에 따라 당국은 나이아가라 강과 강의 지류의 수질을 향상시키는 몇몇 프로젝트를 시행할 계획이다. 이 프로젝트는 지역 수도로 들어가는 미처리 하수 범람을 증가시키는 빗물을 흡수하고 저장하기 위해 녹색사회기반시설을 사용한다. 당국은 2년동안 프로젝트에 3억8천달러를 투자하기로 결정했다.

빌딩의 하수와 거리의 빗물을 나르는 합류식 하수도는 폭우가 오면 완전히 뒤덮혀지고 미처리 하수를 지역수로 보낸다. 폭우와 해빙기간동안 합류식 하수도의 폐수의 양은 하수 처리를 위한 플랜트 수용량을 초과하면 미처리 하수를 포함한 폐수를 직각적으로 근처 수역으로 배출한다. 이러한 범람은 빗물과 산업폐기물, 유독성 오염, 쓰레기, 사람에게 유해한 물질을 포함한다. 매년 버펄로 시의 합류식 하수도는 17억5천만 갤런의 양을 나이아가라 강과 강의 지류로 범람한다.

DEC의 승인에 따라 당국은 Bird Island 폐수 처리 시설의 배출과 합류식 하수도의 범람을 허락한다. 1999년의 승인은 합류식 하수도를 관리하기 위한 장기간 제어 계획 개발을 요구했고, 당국은 2004년 장기간 제어 계획을 제출했지만 적절하지 않아 승인되지 않았다.  

2012년 3월 9일 환경보호국은 공표한 규정에 맞는 승인 가능하고 하수 처리 개선을 보증하는 장기간 제어 계획 제출을 당국에 요청하고 구체적인 실행 계획 개발을 요구했다.

환경보호국과 New York State Department of Environmental Conservation은 당국이 녹색사회기반시설 프로젝트의 계획에 포함되도록 장려했다.

The Buffalo Sewer Authority's (Authority) plan to reduce the amount of sewage and stormwater runoff that flow from the city of Buffalo, N.Y.'s combined sewer system has been approved by the Environmental Protection Agency (EPA) and the New York State Department of Environmental Conservation (DEC).

The plan has been incorporated into a legal order issued by the EPA to the Buffalo Sewer Authority. Under the approved plan, the Authority will implement a series of projects that will improve water quality in the Niagara River and its tributaries, including projects that use green infrastructure to soak up and store stormwater that would otherwise increase overflows of raw sewage into local waterways. The Authority has committed to investing $380 million on these projects over 20 years.

Combined sewer systems (CSS), which carry sewage from buildings and stormwater from the streets, are overwhelmed during heavy rain and send untreated sewage into local waters. During periods of heavy rainfall or snowmelt, the volume of wastewater in a CSS can exceed the capacity of the plant that receives the wastewater for treatment. 

When this happens, CSSs discharge excess wastewater containing untreated sewage directly into nearby water bodies. These overflows not only contain stormwater and untreated human and industrial waste but also toxic pollutants and debris. It is estimated that Buffalo's CSS contributes over 1.75 billion gallons of combined sewage overflows (CSO) to the Niagara River and its tributaries each year.

Under a permit issued by the DEC, the Authority discharges from its Bird Island wastewater treatment plant outfalls and from CSO points into the Niagara River, Black Rock Canal, Erie Basin, Buffalo River, Scajaquada Creek, Cazenovia Creek, and Cornelius Creek. Its 1999 permit required it to develop a Long Term Control Plan to manage its combined sewage. Further, the Authority submitted a Long Term Control Plan in 2004, which was found to be inadequate and not approved.

A March 9, 2012, a compliance order issued by the EPA required the Authority to submit an approvable Long Term Control Plan to the DEC that would include sewer system improvements to ensure that CSOs complied with technology and water quality-based requirements. The legal order also required the Authority to develop a detailed implementation schedule that would take finances into consideration while meeting water quality standards. Both the EPA and the DEC encouraged the Authority to incorporate green infrastructure projects into its plan.

On January 10, 2014, the Authority submitted its final revised Combined Sewer Overflow Long Term Control Plan to the EPA and the DEC for review and approval. The plan was approved on March 18, 2014. The EPA is now issuing an amended compliance order memorializing its and DEC's approvals of the Authority's Long Term Control Plan and implementation schedule with a 2034 final compliance deadline. The Authority has already invested over $50 million in completed and ongoing construction projects under its approved Long Term Control Plan.

In addition to these projects, $93 million will be spent on green infrastructure for between 1,315 and 1,620 acres of impervious surface throughout Buffalo. Projects will include vacant property demolitions, vacant lot modifications to allow for infiltration, pervious pavements, rain gardens, downspout disconnections and rain barrels. The Authority will also invest $41 million in upgrades at its Bird Island Wastewater Treatment Plant to increase the treatment capacity for sewage and stormwater runoff and to ensure that all discharges receive adequate disinfection. Other projects will increase the system's ability to collect and transport wastewater. The Authority estimates that total costs will be approximately $380 million over 20 years.

[출처 = Waterworld / 2014년 4월 14일]