Washington D.C. has truly transformed over recent years and continues to grow. EPRO was recently involved in a critical project located in an up-and-coming area of the city, called Florida Avenue NE. This corridor has multiple land uses and several critical public transit connections and is also experiencing a high level of new development.

“This project was an adventure for me,” explains Daniel Hammill, EPRO’s technical support specialist. “From setting up a new EPRO spray pump on location, exposing and handling unexpected underground streams, and on-the-spot project design changes, EPRO’s technical team and approved applicator Osprey Contracting Company stepped up to the challenge presented to us and provided successful solutions for the project.”

The project, the 1 Florida Ave NE condos by Aria Development Group, is under construction. Plans call for 388 apartments which will be situated on the site of a former Exxon gas station at the corner of North Capitol Street and Florida Avenue NE.

A non-detensioned tieback being sealed with EPRO’s e.roll reinforcement detail.

Gas stations can often cause contamination issues to the surrounding soil. Here, one of the underground storage tanks had leaked into the soil, causing a complete exposure pathway from the groundwater to the indoor air. Testing revealed that ethylbenzene, xylenes, naphthalene, and TPH-GRO‘s (Total Petroleum Hydrocarbons – Gasoline Range Organics) were all present. This meant that the groundwater and soil were both impacted, so the new below-grade construction had to have a solid waterproofing system that was also effective at vapor intrusion mitigation.

“As the project began to unfold,” says Hammill, “we discovered there was flowing water coming in from an unanticipated underground stream that was running directly across the bottom of the elevator pit. This flooded the area where the under slab and pile caps had to be detailed.”

He adds, “EPRO’s technical team, Osprey’s experienced application team, and the GC, HITT Construction, were able to determine how to safely and efficiently redirect the stream’s flow to allow for a warrantable waterproofing installation.”
With such a complicated project, the selected systems had to be versatile enough to cover several different site elements: an underslab vapor intrusion barrier, waterproofing for elevator pits, and pre-applied/post-applied waterproofing wall systems.

“This site location was difficult,” explains Kevin Leasure with Osprey Contracting Co. “It’s right in downtown D.C. and on a corner. Logistical challenges drove the design of the building, and it needed multiple levels, plus there was lagging involved. In addition, the job was going to require both a robust under slab and vapor intrusion system and complicated waterproofing details; it felt like every system possible would be used.”

EPRO stepped in with the right products and expertise to advise the team on the best way to protect the site. A total of 47,000 square feet of product was applied: Geo-Seal EV40s with passive low-profile venting for vapor mitigation; e.base, e.spray, Geo-Seal Bond B at the elevator pits; 12,500 square feet of E.Proformance Slip Sheet at shoring for the blindside walls, and 7,500 square feet of the post-applied E.Proformance Wall system for the double-formed walls.

Application of EPRO’s E.Proformance Shoring system in conjunction with rebar on a busy job site.

E.Proformance is ideal for below-grade building foundations not subjected to constant hydrostatic pressure but require waterproofing protection and a single source warranty for both waterproofing and contamination such as methane gas, volatile organic compounds (VOCs) or aeromatic hydrocarbons. And Geo-Seal EV40s consist of an EVOH membrane combined with a robust geotextile layer to provide a single-sheet vapor intrusion barrier that is chemically resistant and easy to install while also providing improved protection during the installation process.

“The variety of systems that EPRO could offer that could fit each unique condition made our job much easier,” says Leasure. “It was also helpful that EPRO made project specific details available, as well as helped plan a lot of complicated transitions.”
Hammill acknowledged, “While we understand that waterproofing and vapor barriers aren’t the most exciting aspect of a project, we and our approved applicators know that we are the most critical piece of the puzzle in keeping the building dry and safe for everyone living and working there in the future.”