Owner: City of Carlsbad
Engineer: Molzen-Corbin & Associates
Location of Project: Maljamar, NM
Final Contract Amount: $9,351,098
Completion Date: June 2015
The New Phase I – Double Eagle Waterline Project presented many unique challenges, so the Owner chose to use a qualifications-based selection process to select AUI as the Contractor. The project scope included:
- Over 3.5 miles of 24” water transmission line
- Over 11 miles of 16” water transmission line
- Four jack and bore crossings under state and county roads and 59 jack and bore crossings under other utilities
- Four pressure reducing/pressure sustaining stations in pre-cast concrete structures
- Associated shutoff valves, air release/vacuum valve stations, and appurtenances
Located between Carlsbad and Hobbs, the Project spanned a remote area of about 20 miles. The numerous hills and soft, sandy soil required 4-wheel drive trucks to traverse and limited the ability to get equipment in and out.
The Project area contained dozens of gas and oil lines, from 2” to 16”, running both above and underground. More than one excavation site had in excess of 30 existing utility lines that had to be protected while carefully trenching in the area. Many of the underground lines had to be crossed by the new waterline. All major underground crossings required jacking and boring, and lines were buried up to 13-feet deep, requiring bore pits of 16- to 17-feet. To further complicate the situation, the oil and gas lines running through the Project area had more than 30 different owners.
Approximately two-thirds of the Project area was designated as an “Environmental Area.” This area is habitat for the potentially endangered Sand Dune Lizard and Lesser Prairie Chicken. In addition to providing special precautions to protect these species, any wildlife discovered in the active Project area had to be relocated by the New Mexico Environmental Department (NMED) monitor prior to work continuing. Even rattlesnakes were protected in this area, and some were encountered during the Project. This area was also restricted to having no more than 400 feet of trench open at any one time. Even though the total contract time allowed for the Project was one year, all of the work in the Environmental Area (2/3 of the job) had to be constructed between August 1st and November 30th to avoid disrupting the nesting season of the Sand Dune Lizard. This seemingly insurmountable schedule milestone was met by overlapping crews working 16-hour days, seven days a week, including staggering lunches for crews so that equipment never stopped working.
Because the locations for water were so far apart (only four locations over the 20-mile Project area), and the terrain was not suitable for water trucks, we had to find another way to get water for dust control and backfill to the needed locations. The Project superintendent had our crews weld taps into the existing steel waterline every 5,000 feet. He then used 2,500-foot sections of 2-inch poly hose with a tee installed every 500 feet to have water available anywhere it was needed.
These are just a few of the many unique challenges that had to be overcome to successfully complete the Project. By responding to the challenges with innovative solutions, AUI completed the Project on time and on budget with a high level of quality.