McAlpine Creek Wastewater Management Facility

Thermal Hydrolysis Process and Biosolids Improvements Project

Program Overview:

Charlotte Water is embarking on a multi-year, multi-phase program to implement a diversified, sustainable biosolids treatment strategy that aligns with CLTWater’s capital investment and operating costs capabilities. A key component of this program is to regionalize solids processing at McAlpine Creek Wastewater Management Facility (WWMF), which will include Sugar Creek, Irwin Creek and future Stowe Regional treatment plant solids.

This program will improve the biosolids quality including enhanced pathogen and odor reduction for land application and other beneficial uses, achieving Charlotte Water goals for environmental stewardship and long-term sustainability, and ultimately diversifying options for biosolids users.

The new treatment process that will be implemented, called thermal hydrolysis, is a more energy sustainable process with a lower total carbon footprint, resulting in lower life-cycle cost for Charlotte Water and the community.

Currently, CLTWater produces biosolids as a Class B product, meaning it can be used safely on agricultural land through our partnership with local farmers. Charlotte Water will continue to offer its high-quality Class B biosolids for land application users.

Centralizing solids processing at the McAlpine Creek WWMF will maximize opportunities for energy production and Class A technology utilization, as well as other resource recovery including nutrient harvesting, a process in which a portion of the nutrients (primarily phosphorus) are extracted from the solids and recovered as a fertilizer product. Class A biosolids can be safely used on lawns and gardens as well as agricultural lands.

Program Goals:

The goal is to advance the level of treatment, diversify product market opportunities, enhance resource recovery and reduce overall greenhouse gas emissions and carbon footprint.

Program Timeline:

Key milestones in the process. Please note future construction schedules are subject to change due to unforeseen delays.

Wastewater Process Map Graphic

  • Biosolids Master Plan – 2012 to 2013
  • Biosolids Market Study – 2016 to 2019
  • Selected thermal hydrolysis process (THP) as the treatment technology – December 2019
  • THP Preliminary Engineering Report – 2020 to 2021
  • Selected Design-Build Team – June 2020
  • THP Improvements Design Development – September 2022 to 2024
  • THP Construction – January 2025 to December 2027
  • THP Facilities Online and Operational – Spring 2028