DESIGN STANDARDS FOR WASTEWATER TREATMENT WORKS IN THE LAKE GEORGE BASIN March 2015 www.dec.ny.gov Foreword The Clean Water Act (CWA) was enacted to restore and maintain the chemical, physical and biological integrity of the nation’s surface waters. This was to be done by reducing direct pollutant discharges into waterways, financing municipal wastewater treatment facilities, developing technology necessary to eliminate the discharge of pollutants and by managing polluted runoff. In New York State, Article 17 of the Environmental Conservation Law (ECL), “Water Pollution Control,” was enacted to protect and maintain both surface and groundwater resources. It authorized the creation of the State Pollutant Discharge Elimination System (SPDES) Program to protect New York's water resources. Pursuant to ECL Article 17 Section 1709, surface water discharges of sewage or treated sewage effluent to Lake George or other surface waters within the Lake George drainage basin are prohibited. Subsurface discharges of less than 1,000 gallons per day from an On-site Wastewater Treatment System (OWTS), without the admixture of industrial or other waste, are regulated by the New York State Department of Health (NYSDOH) and administered by local municipalities. Subsurface discharges of 1,000 gallons per day or more from an OWTS, without the admixture of industrial or other waste, must be covered by a SPDES permit issued by the New York State Department of Environmental Conservation (NYSDEC). Design standards for large Publicly Owned Treatment Works (POTWs) have been updated independently by the Great Lakes-Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers (GLUMRB) and the New England Interstate Water Pollution Control Commission (NEIWPCC). Design standards for small individual residential systems are updated by NYSDOH, local county health departments or watershed organizations. These Design Standards for Wastewater Treatment Works in the Lake George Basin (Design Standards) are being updated by NYSDEC to meet the needs not addressed by the large and small systems design standards (refer to Appendix A for the applicable technical standard). Over the last 20 years, OWTS technologies have increased in the level of treatment provided and in complexity of design and operation. It is appropriate that the Design Standards are updated now to remain current with the needs of the wastewater treatment system design professionals. Numerous references to the GLUMRB’s Recommended Standards for Wastewater Facilities, (Ten States Standards), 2004 and NEIWPCC’s Guides for the Design of Wastewater Treatment Works -Technical Report-16, 2011 (TR-16), appear in this manual. Ten States Standards has been adopted by NYSDEC as New York State’s official standards for municipal wastewater treatment and collection facilities according to 6 NYCRR Part 750-2.10(g)1. Ten States Standards may be viewed at: http://10statesstandards.com, and is available in print from Health Education Service, Inc., P.O. Box 7126, Albany, New York 12224, i 518-439-7286. Health Education Services (HES) may be accessed online at http://www.healthresearch.org. TR-16 is also an acceptable design standard for municipal systems of any size, or any non-municipal, intermediate sized systems that treat only sanitary wastewater. TR-16 addresses standards for alternative collection systems such as vacuum sewers, low pressure/grinder pump sewers, septic tank effluent (pump) and septic tank effluent (gravity) sewers (STEP/STEG). NYSDOH regulations for residential wastewater treatment systems discharging less than 1,000 gpd are entitled “Appendix 75-A, Wastewater Treatment Standards – Residential Onsite Systems.” Design guidance for residential onsite systems are published under the title Residential Onsite Wastewater Treatment Systems Design Handbook. The NYSDOH Design Handbook is available from HES. Both documents are on the NYSDOH website. ii Table of Contents Foreword ........................................................................................................................................................ i List of Acronyms ....................................................................................................................................... viii List of Tables ............................................................................................................................................. xiii List of Figures ............................................................................................................................................ xiv Disclaimer ............................................................................................................................................... xv Introduction........................................................................................................................................ Intro - 1 Purposes of These Design Standards: ............................................................................................ Intro -1 How to Use These Design Standards: ............................................................................................ Intro -2 A. Facility Planning and Permitting..................................................................................................... A - 1 A.1 Introduction ............................................................................................................................. A - 1 A.2 Planning and Permit Application Process ............................................................................... A - 1 A.3 Obtaining a SPDES Permit for a Wastewater Discharge ........................................................ A - 3 A.4 State Environmental Quality Review (SEQR) ........................................................................ A - 5 A.5 Asset Management .................................................................................................................. A - 5 B. Project Evaluation ........................................................................................................................... B - 1 B.1 Introduction ............................................................................................................................. B - 1 B.2 Site Evaluation ........................................................................................................................ B - 1 B.3 Separation Distances ............................................................................................................... B - 1 B.4 Soil Evaluation for Subsurface Discharge .............................................................................. B - 5 B.4.a Deep Soil ............................................................................................................................. B - 7 B.4.b Percolation Testing ............................................................................................................. B - 8 B.5 Locating Facility Relative to Flood Plains ............................................................................ B - 10 B.6 Design Criteria ...................................................................................................................... B - 12 B.6.a Wastewater Characterization ............................................................................................ B - 12 B.6.b Design Flow ...................................................................................................................... B - 15 iii B.6.c Infiltration, Inflow, Non-Sanitary and Prohibited Flows .................................................. B - 20 B.6.d Treatment Considerations and Effluent Limits ................................................................. B - 22 B.7 Groundwater Monitoring and Monitoring Well Requirements ............................................ B - 22 C. Sewers and Sewage Pumping Stations ............................................................................................ C - 1 C.1 Introduction ............................................................................................................................. C - 1 C.2 Building Sewers ...................................................................................................................... C - 1 C.3 Conventional (solids handling) Gravity Sewers, Manholes and Pump Stations ..................... C - 2 C.3.a Conventional Gravity Sewers ............................................................................................. C - 2 C.3.b Conventional Sewer Manholes ........................................................................................... C - 4 C.3.c Sewage Pumping Stations ................................................................................................... C - 5 C.4 Effluent Sewers ....................................................................................................................... C - 9 C.4.a Septic Tank Effluent Gravity (STEG) Sewers .................................................................. C - 13 C.4.b Septic Tank Effluent Pump (STEP) Sewers ...................................................................... C - 15 C.4.c Septic Tank Effluent Manholes and Cleanouts ................................................................. C - 16 C.5 Conventional Force Mains .......................................................................................................... 17 C.6 Small Diameter Solids Carrying Sewers: