Senior Environmental Scientist III

Are you driven to grow, lead, and make a meaningful impact? At Apex, we’re building more than a consulting and engineering firm—we’re creating a place where your career accelerates, your contributions matter, and your potential is fully realized.

Here, you’ll work on projects that shape communities, protect the environment, and create lasting impact, all while being empowered with the autonomy and flexibility to do your best work. Fueled by high quality delivery, exceptional client retention, and strategic acquisitions, Apex Companies continues to rank among the fastest‑growing firms in the AEC industry, recently recognized by the Zweig Group for our industry‑leading growth.

Our success is grounded in strong leadership, a collaborative culture, and a shared commitment to delivering exceptional outcomes.

As we continue to grow, we’re focused on building a team of high‑performing professionals who are ready to lead, collaborate, and push what’s possible. At Apex, you don’t just join a company, you help shape what comes next.

We have an exciting opportunity for an outstanding individual to join our team as a Senior Environmental Scientist III at our headquarters in Fullerton, California
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This is not a "job" – it is a career with a rapidly‑growing organization in a dynamic industry that recognizes excellent performance and provides opportunities for growth and advancement. It offers a chance to develop valuable engineering and technical skills under industry‑recognized leaders and to contribute to environmental and community improvement.

• Responsible for assisting municipal, utility, industrial, and commercial clients with stormwater planning and compliance efforts associated with Phase I and II Municipal Separate Storm Sewer System (MS4) Permits, the Construction General Permit (CGP), and Industrial General Permit (IGP).
• Interpret complex regulatory permits, assist clients with regulatory compliance, prepare technical reports, conduct environmental compliance inspections and sampling, and complete high‑quality deliverables on time and within budget.
• Lead environmental sampling, testing, and observations (primarily surface water, stormwater, groundwater, wastewater).

• Interpret regulatory permits and formulate compliance strategies.
• Prepare comprehensive approaches, work plans, technical reports and documents (watershed management plans, stormwater management plans, annual reports, non‑stormwater discharge source assessments, adaptive management plans, compliance guidance documents, compliance reports, rain and sampling event summary reports, SWPPPs, WQMPs, etc.).
• Execute/manage field investigations.
• Manage workload of other Environmental Scientist staff.
• Prepare/Monitor Project Budgets.
• Meet with clients regarding work and performance of team, and regarding current and future work.
• Perform construction site and facility environmental compliance inspections (QSP, QISP, FOG).
• Conduct environmental sampling, testing, and observations (primarily surface water, stormwater, groundwater, wastewater, along with soils and sediments).
• Make field observations and perform data measurement and collection assignments.
• Data management and analysis (compilation, manipulation, and evaluation of data).
• Develop and implement monitoring and reporting plans and field studies.
• Perform regulatory and water quality data analyses.
• Participate/lead in technical presentations.

• BS in Environmental Science, Civil or Environmental Engineering, or a related field.
• 5+ years of professional work experience.
• Knowledge of stormwater permitting and planning; water quality monitoring; BMPs; and environmental compliance inspections.
• CPSWQ/CPESC certification.
• QSD or QSP and QISP certifications.
• Able to read, interpret, and analyze plans, technical manuals, and permits.
• Strong analytical skills.
• Ability to pay attention to detail with a high level of accuracy.
• Demonstrates a strong work ethic.
• Excellent writer and communicator.
• Proactive approach/self‑starter/takes initiative/positive attitude/team player.
• Proficient in Microsoft Office Suite.
• Ability…