Specifications include, but are not limited to: Engineering services to design a drinking water treatment facility for the removal of Per- and Poly-Alkyl Substances (PFAS) from the Greenland Well water supply source. 1. Meetings a. Portsmouth Team (assume bi-weekly for four months) b. Greenland Selectboard (assume two meetings) i. Property use and ownership discussions 2. Site Investigation a. Geotechnical Testing b. Test Pitting and Infiltration Testing c. Site Topographic and Boundary Survey d. Hydraulic flow testing to ensure sufficient supply capacity to meet filter backwash requirements. 3. Process Layout a. Granular activated carbon (GAC) filter vessel(s) sized appropriately for PFAS removal rates and well permitted capacity. b. Process piping retrofit from existing pump head through filter/addition and return to existing piping (chemical injection and outlet to system). c. Piping layout shall include: i. Easy access for media load-in and load-out ii. Filter bypass iii. Provisions for potential additional ion-exchange polishing filter. iv. Filter-to-waste piping to exterior for frac-tank or infiltration basin discharge. v. Provisions for connecting the Greenland backup well into the treatment system. 4. Site Plans a. Investigate options for managing backwash and filter-to-waste water during the GAC load-in/conditioning process. b. The option of an infiltration basin shall be considered as this location does not have sewer and is near a wetland and stream. c. Facility access and access road improvements shall be considered and included in the final plans if so directed by the City. 5. Building layout shall include: a. Sufficient space for accessing and working around GAC filter. b. Sufficient space for the potential addition of ion-exchange vessel(s) capable of removing PFAS at the permitted well capacity. c. Optimize use of existing building to minimize footprint of addition. d. Shall meet requirements of all applicable building codes. 6. Plan Review, Certification and Approval a. All plans shall be reviewed and certified by NH licensed Professional Engineers qualified in associated practice areas. b. Plans shall be submitted to and approved by the NH DES Drinking Water And Groundwater Bureau in accordance with NH Code of Administrative Rules Chapter Env-Dw 404.
