Sustainability (or “green”) engineers can fall into several engineering disciplines: mechanical, electrical, environmental, civil, or structural. Whatever their current position, though, all have the same goal: find and implement ways to reduce the use of non-renewable resources and minimize an organization’s environmental impact. Private companies and public-sector agencies have hired more sustainability engineers over the past few years. Many in upper management now believe that sustainable business practices will increase productivity, reduce costs, and boost energy efficiency. What an engineer actually does for an organization can vary wildly. While a sustainability engineer at Toyota might work on cooling large industrial buildings with rooftop gardens, her colleague at a city agency might spend time making sure all the air conditioners in an office meet regulations. Or, in a more extreme example, someone working in hazardous-waste management needs different expertise than someone working exclusively on a residential electric grid. Regardless of the size or sophistication of the company, an engineer’s job requirements may include developing energy-optimization models, keeping abreast of (and implementing) new technologies, ensuring that any sustainability plan is followed, and crafting short- and long-term goals. A successful engineer also takes human behavior into account when developing programs and helping promote more energy-efficient habits. Monica Watkins, Deputy Chief for Engineering for the City of Baltimore’s Housing Authority, is a mechanical engineer with an MBA and over 18 years of local utility experience in the areas of gas engineering and construction, energy accounting and billing, and electric policy, rates and regulations. She also is a member of the Association of Energy Engineers, a Certified Energy Manager (CEM) and a Certified Measurement and Verification Professional (CMVP). Reducing energy and water consumption is a key part of her department’s primary mission, as well as improving environmental conditions for housing authority residents. “The opportunity was there for us to look for ways to conserve energy and to do it most effectively,” she said. “We focused on five of our properties where we could change our inefficient lighting, both within the dwelling units and site wide. We looked at the most efficient use of all of our water fixtures and toilets and changed those out, and we looked for opportunities to make better use of our heating systems, as well.” Her mission comes with significant challenges, including problematic infrastructure, aging buildings and older streets. Underground utilities prevented her from sinking the equipment for a geothermal system into the ground, for example. Watkins manages a staff of 19 who are responsible for everything from environmental monitoring to analysis and energy conservation. While the department collects and extrapolates much of its data from utility management software EnergyCAP, it also relies on a variety of other software tools. Sustainability engineering groups in general must become wizards with Excel, especially if they’re dealing with enormous datasets (such as survey results). One of the big upsides to sustainability engineering is that its successes are quantifiable, especially in terms of energy and money saved. It’s clear when initiatives are working. “We have a success rate that averages 90 percent across the developments that are metered right now,” Watkins noted. Her successes may keep multiplying as her department transitions even more buildings to an energy-efficient model.