The Window/Wall Noise Attenuation “E” Designation is related to exterior noise impacts on building occupants. The OER typically requires maximum interior noise levels ranging from 30 dBA to 45 dBA with windows closed and an alternate means of ventilation.

The required interior noise level is obtained by mitigating exterior noise with specialized windows with high OITC ratings.

The alternate means of ventilation must bring fresh air into each building unit while the windows remain close. Air conditioning units and trickle vent units are typical ways to address the alternate means of ventilation requirement. 

Air E designation is generally associated with the HVAC system and boilers. The Air E can regulate that a specific fuel type be used (such as natural gas) and the location of the vent stack.

Similar to the Hazmat "E" Designation, the air and noise designations are addressed in two phases, prior to the issuance of building permits and then prior to the issuance of the certificate of occupancy. Before the building permits will be released the OER must have all documents related to the air and noise E designations. Hydro Tech can work closely with the Architect and MEP engineer to secure the approval for these designations.


Hydro Tech has integrated ArcView with other Windows applications such as AutoCad, Excel, and Access on up-to-date PCs to create cost effective, capable GIS. Hydro Tech uses ESRI GIS products to develop specific applications pertaining to facilities management, groundwater management, and utility applications on desktop PCs. Specific GIS services include:

  • Data Management Planning and
  • Customized GIS
  • Database Development Applications
  • Integration of Software Products to GIS
  • Electronic and Hard Copy Deliverables


Environmental Compliance is one of the most important, yet commonly overlooked, aspects of environmental fieldwork. Federal and State environmental regulations are complex and multi-faceted. Fortunately, every member of our staff has worked with the regulatory agencies, so we are able to provide complete and thorough information to satisfy a variety of client needs.

  • Storage Tank Management 
  • Emergency Planning/Right-to-Know
  • Compliance Audits
  • OSHA Audits
  • O&M Programs
  • Health & Safety Programs
  • SPCC
  • CBS Spill Response Plans
  • Federal/State Closure Reports
  • Permit Expediting
  • RCRA & TSCA Audits
  • NYC "E" Designation