Sign up for News

Sign Up Now!

Be the first to know when NAT 2018 Conference registration opens, when sponsorships become available, about new short courses and technical sessions, and much more!

Off-site Field Trips & Technical Tours


Discover new innovations, create meaningful dialogue and get inspired by participating in an off-site field trip and technical excursion.

Tour attendees will have transportation and appropriate food and refreshments while on the tours. Tours usually include an opportunity to leave the busses and get an up-close look at the project with guidance from project managers.


North East Boundary Tunnel Segments Factory
Wednesday, June 27, 2018 | 12:00 PM – 5:00 PM | $25

Busing and onsite lunch provided by DC Water/ Salini-Impregilo-Healy (SIH) Joint Venture

The purpose of this field trip is to visit the concrete tunnel segment factory for DC Clean Rivers’ (DCCR) $580M North East Boundary Tunnel. The NEBT is part of the DCCR Combined Sewer Overflow (CSO) Long Term Control Plan that will reduce CSOs to the Anacostia River by 98% and reduce flooding in the Northeast and Northwest parts of the District of Columbia. The NEBT Project comprises 27,000 feet of 23-foot internal diameter soft ground tunnel ranging in depth from 80 to 160 feet. The project also includes seven deep shafts, five diversion chambers, seven adits, several stormwater inlets, two ventilation control vaults, and an 80,000 cfm above grade and two 3,000 cfm below grade ventilation control facilities.

The field trip is intended for engineers, contractors, and owners. The scope of the field trip is to expose the audience to the process followed to manufacture high quality segments for tunnels operated under severe environmental conditions. The audience will witness the segment manufacturing process. The process elements covered during the tour will include: the preparation of the moulds, concrete batching with fibers and delivery to moulds, the finishing of concrete, the curing of concrete, de-moulding, and the stacking and final finishing of segments, secondary curing, yarding, and testing.

Attendees should wear appropriate seasonal casual clothes and steel toe boots. The site will provide PPE including hard hat, gloves, reflective vest, safety glasses, ear protection, and dust mask. Attendees will need to wear steel toe boots.

  • Maximum registration: 40 people

DC Water 250 MGD Tunnel Dewatering pump station
Wednesday, June 27, 2018 | 12:00 PM – 4:30  | $75

The purpose of this field trip is to tour DC Water’s new 250 mgd Tunnel Dewatering Pumping Station (TDPS) and screening devices constructed at the terminus of Blue Plains Tunnel on top of the 132ft and 76ft internal diameters respectively. The TDPS allowable minimum firm discharge capacity is 225 mgd, which is equal to the capacity of the Enhanced Clarification Facility (ECF). The TDPS is expandable to 500mgd. In addition, the facility will have the ability to dewater the tunnel the system up to the new ECF and be able to discharge ECF effluent to complete treatment and discharge at Outfall 002 or at Outfall 001.

The field trip is intended for engineers, contractors, and owners interested in the processes used for treatment of Combined Sewer Overflows to meet the Water Quality standards. The audience will be exposed to the coarse screens at the tunnel terminus, pumps and their controls, fine screens, grit removal process, high rates clarifies, etc.

Attendees should wear warm, casual clothes. The site will provide PPE hardhats if needed.  No other gear or equipment is needed.

  • Maximum registration: 40 people

Purple Line Tunnel Project
Wednesday, June 27, 2018 | 12:00 PM – 4:00 PM | $75

Visit the Purple Line tunnel project being built by Traylor Bros. Inc.  The tour emphasis will be on shotcrete and SEM/NATM operations.  Tour begins with a presentation in conference room and is followed by site and tunnel visit. 

Attendees should wear warm, casual clothes and steel toe shoes/boots.  The site will provide PPE.

  • Maximum registration: 12 people