Taking advantageof full flow: Wet weather flow management by in-stream storage

Henrico’s collection system conveys an average annual flow of 170 ML/d (45 mgd) to its WRRF, which has a current capacity of 284 ML/d (75 mgd). The system is a separated sewer system currently serving approximately 36,000 ha (89,000 ac) and 330,000 people in an urban region just north of Richmond, Va. The wastewater collection system is similar in nature to other urban collection systems and...

As with most urban counties, Henrico County experiences a steady increase in population. There is a potential for new development in the eastern end of the county and continued buildout and redevelopment in the western end. The comprehensive master plan to ensure the most effective wastewater conveyance includes many stages. However, the two main parts are to build additional in-line storage in...

The FEP significantly reduces costs, when compared with increasing downstream conveyance system piping, while providing the necessary storage to handle peak wet weather flows as well as operational flexibility in conveyance. This type of combined flow conveyance and peak-flow equalization facility is normally used in combined sewer systems and not in separated sanitary sewer systems. The...

The second phase of the in-stream master plan includes the planning and design of a 113 million L (30 million gal) in-system wastewater storage facility called the Upham Brook Trunk Sewer and Storage Facility. (See Figure 2, above.) This facility will be built on a site located more than 24 km (15 mi) upstream of the WRRF. The facility is currently planned to use prestressed concrete reinforced...

Odor control, on any wastewater equalization system that includes an equalization pipeline system, is always a key design consideration. The odor control systems for the FEP have been divided into two phases.

Planning a project this large and complex led to several insights. First, deliberate planning and implementation provides justification and results. This is exemplified in this project via how the designers are seeking to tie the sewer system plan to the land use growth plan to ensure system reliability as well as the most cost-effective plan. This staged and multifaceted approach also provides a...