Lambert Polinder serves as a member of the general board for Waterschap Vallei en Veluwe since June 2019, participating in significant decision-making regarding policies, laws, tax rates, and budgeting. Additionally, Lambert assists SGP-fractie board members as a commission member. With extensive experience in the agricultural sector, Lambert has held roles such as environment lawyer for Agrifirm since June 2013, where legal representation and advice for agricultural clients is provided. Previous positions include team leader at Agrifirm Exlan and various advisory roles, including owner of Polinder Advies, focusing on environmental and spatial planning issues. Lambert's educational background includes a BSc in livestock farming and biotechnology from CAH Dronten and an SVM diploma in agricultural real estate management.