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Highland Terrace Estate

Project Details

Architect :    Garnett DePasquale
Project Type :    Renovation
Services :    Civil Engineering
Surveyor :    David Saskas
Builder :    Men at Work

Project Summary

The proposed renovations to this existing 12 bedroom estate drove the requirement to replace the existing septic system with a new I/A-OWTS. The project scope also included the construction of a pool pavilion between the existing pool and tennis court which required it's own dedicated septic system. The intent was to to integrate the new septic systems without disturbing existing site features, landscaping and drainage.

Engineering Challenges

Despite being set on a large lot, this project posed several design challenges.
First, there was a limited amount of space as the goal was to fit the main house system where the existing system was located as well as minimizing impact to the rest of the site. This can often prove to be difficult as the new I/A-OWTS system footprints tend to be larger than a traditional system.

The other challenge was to re-use the existing waste lines so that the client did not have to redo the interior plumbing to accommodate the new septic system. This be be especially challenging when trying to limit impact to existing site elements. Additionally, I/A-OWTS systems are often limited in their inlet configurations as compared to a traditional septic system.

Core Design Concepts

Multiple Septic Lines

Especially in larger homes, it is fairly common for houses to be plumbed with multiple septic lines exiting the building to an existing septic system.
When replacing an existing system, we strive to minimize the amount of interior plumbing modifications and overall cost to install for our clients.
Allowable inlet configurations are determined by the manufacturer of the I/A-OWTS in cooperation with the local regulating body and in Suffolk County bends in the waste line's are typically prohibited. While there is some additional flexibility when renovating existing sites, care must be taken to utilize an approved configuration for the specific tank chosen.

Pool Pavilion

When designing a septic system for an accessory structure there are two main approaches - tie the waste line into the main house or propose a standalone system. In this case, the proposed pool pavilion was very far from the main house so a dedicated traditional system was proposed (generally, an I/A-OWTS is not required for accessory structures). The sizing of the system depends on whether the structure is for seasonal or year round use and if there is an intention for it to be used as living space (i.e. bedrooms).

FujiClean CEN-14

There are currently (2) I/A-OWTS technologies fully approved for use in Suffolk County - FujiClean and HydroAction. In this case, a FujiClean CEN-14 with a capacity for 12 bedrooms was selected as it allowed us to save space and cost by having one system for the entire main house as opposed to multiple systems.