HR Generalist/Employee Relations/Payroll

HR Generalist
SewerAI is hiring an HR Generalist to help scale our People function and support an exceptional employee experience as the company continues to grow past 100 employees. This role adds dedicated, experienced capacity across People Operations, HR administration, the employee lifecycle, and HR compliance.
You bring 4+ years of hands-on HR experience, whether as a generalist or in a specialty area, and you thrive in a fast-paced startup environment where priorities move quickly and every team member plays a meaningful role. You will work closely with the Head of People and partner with the Recruiting team to keep People processes, employee support, and HR operations running smoothly as the organization scales.
At SewerAI we Demand Greatness — holding ourselves and each other to a high standard while supporting one another in doing meaningful work that impacts the communities and infrastructure we serve. This position is designed with a clear path into a more senior HR role over time.
Core HR & People Operations

Support day-to-day HR activities across the full employee lifecycle.
Coordinate payroll inputs and changes in partnership with Finance, ensuring accuracy and timeliness.
Own HRIS data integrity — records, reporting, and system hygiene — and generate People reports and dashboards for leadership.
Build and maintain accurate headcount data in Rippling, keeping records current and reporting-ready, and ensure employee data accuracy across People systems such as Rippling and Carta.
Coordinate offboarding logistics and equipment returns.
Support HR compliance initiatives, audits, and documentation across applicable federal and California requirements.
Maintain People policies, documentation, and internal People resources, and support and maintain the People intranet workspace in Notion.
Administer engagement and pulse surveys and prepare clear reporting on the results.
Support the company's 360 performance review program, including coordination, communications, tracking participation, and supporting leaders through the review cycle.
Assist in training managers on HR procedures, policies, and People processes to ensure consistent and compliant practices across the organization.
Provide day-to-day employee relations support and escalate sensitive matters to the Head of People with sound judgment.
Support employee engagement activities, internal People programs, onsites, offsites, and company travel logistics.
Partner with Recruiting on joint initiatives such as employer branding, candidate experience, and hiring events.
Office & Systems Support

Handle office duties including mailings, shipments, and company swag — including new-hire welcome materials — ordering, packaging, and distribution.
Manage equipment ordering and coordinate with IT to support employees across the company.
Core HR operations — benefits, payroll, 401(k), leave, and HRIS — run accurately and on time without leadership intervention.
Employees receive timely, accurate support across HR, benefits, equipment, and internal processes.
People leadership is freed from execution to focus on strategy, employee relations, retention, and manager development.
5 years of hands-on HR experience, as a generalist or in a specialty area (e.g., benefits, HRIS, compliance, or employee relations).

• Working knowledge of HR compliance, ideally including California employment requirements.
• Comfortable owning HRIS, payroll coordination, and benefits/401(k) administration.
• Technology savvy and comfortable across multiple systems — experience with Rippling, Carta, Notion, and Google Workspace (Docs, Sheets, Slides, Drive, Calendar), or the ability to quickly become proficient.
• Makes effective use of HR and AI tools (e.g., Notion, HRIS, and AI assistants) to work more efficiently and improve People processes.
• Strong judgment and discretion with confidential and sensitive information.
• Able to be in the office at least 2 days per week and reside within a 40-mile radius of Walnut Creek, CA.

Growth Opportunity
This role is designed as a pipeline into a more senior HR position. As SewerAI grows, it will take on deeper ownership across benefits and compliance strategy, policy administration, employee relations, People program design, and cross-functional partnership with Finance, Recruiting, and leadership.
The chance to help shape People Operations at a fast-growing company.
Join the fastest-growing team in wastewater tech and help modernize critical infrastructure with AI. You'll own high-visibility projects, influence how our brand meets the market, and see your work drive measurable impact for customers and communities.
We are committed to providing a workplace free from discrimination or harassment on the basis of age, disability, sex, race, religion or belief, gender reassignment, marriage/civil partnership, pregnancy/maternity, or sexual orientation. All your information will be kept confidential according to EEO guidelines.