Human Health Risk Assessor

The experienced Risk Assessor will work with Leidos Project Managers and Senior Staff and interface with multiple Leidos offices. The Risk Assessor should be comfortable working in a team environment, and demonstrate excellent written and strong verbal communication, as well as organizational skills. Frequent collaboration with the project manager and project team members is expected. The successful candidate will be dedicated to working full-time in support of document preparations and will be an initiative-focused, goals-oriented individual, requiring some supervisory oversight to start. This position is flexible regarding work location (on-site Leidos office locations in Reston, VA; Twinsburg, OH; or St. Louis, MO or remote location). Must be able to obtain access to, and conduct work on, U.S. Government installations. U.S. Citizenship or U.S. Permanent Resident status is required. The salary range for this role is anticipated to be between $85,000 and $100,000 annually. Primary Responsibilities: Assist in conducting human health risk assessments, including development of conceptual site models, selection of appropriate toxicity values, calculation of cancer risks and noncancer hazards, and analysis of uncertainties associated with the risk evaluations. May assist in conducting ecological risk assessments. Provide technical support in evaluating and interpreting quantitative and qualitative environmental sampling data acquired during site investigations. Support preparation of technical reports, including work plans/sampling plans, human health and/or ecological risk assessments, remedial investigation (RI) reports, feasibility studies (FS), proposed plans (PP), and records of decision (ROD). Willing and able to work on a variety of risk assessment- and non-risk assessment-related tasks. Willing and able to travel periodically to Leidos offices and/or project locations. Required Education and Experience: BS degree in Environmental Sciences, Earth Sciences, Biological Sciences, Chemistry, Toxicology, Ecology, or related scientific field. 4 to 10 years of professional experience in the performance of human health risk assessments of exposures to chemicals in environmental media. Working knowledge of EPA human health risk assessment guidance and methods within the framework of the CERCLA RI/FS/PP/ROD process. Ability to compile, manage, and interpret environmental investigation and monitoring data for organic and inorganic chemical parameters. Some experience working with federal environmental regulators. Proficiency in MS Office tools (Excel, Word, Outlook, PowerPoint). Preferred Qualifications: MS degree with 2 to 6 years of professional experience conducting human health risk assessments. Knowledge of environmental statistical methods (e.g., calculation of UCLs, trend analysis) and software tools (e.g., EPA ProUCL, SAS, etc.). Knowledge and experience with EPA online calculators for determining cancer risks, noncancer hazards, and screening levels/preliminary remediation goals. Knowledge and experience with data and/or risk analyses of per- and polyfluoroalkyl substances (PFAS). Understanding of data validation qualifiers indicating usability. Professional experience working with radiological data, as well as human health radiological risk and dose assessments in accordance with the EPA, DOE, and NRC regulatory framework is a plus, but not necessary. Working knowledge of EPA ecological risk assessment guidance and professional experience in conducting ecological risk assessments is a plus, but not necessary. RCRA and CERCLA process documents knowledge (Corrective Action Plans/Reports; RI/FS/PP/ROD). Professional experience working on federal contracts is preferred. Professional experience working with state regulators is desired, but not necessary. At Leidos , we don’t want someone who "fits the mold"—we want someone who melts it down and builds something better. This is a role for the restless, the over-caffeinated, the ones who ask, “what’s next?” before the dust settles on “what’s now.” If you’re already scheming step 20 while everyone else is still debating step 2… good. You’ll fit right in. Original Posting: August 22, 2025 At Leidos , we don’t want someone who "fits the mold"—we want someone who melts it down and builds something better. This is a role for the restless, the over-caffeinated, the ones who ask, “what’s next?” before the dust settles on “what’s now.” If you’re already scheming step 20 while everyone else is still debating step 2… good. You’ll fit right in. Pay Range: Pay Range $72,150.00 - $130,425.00 The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law. Originally posted on Himalayas