Chapter 21, Article 3, §33 of the General City Laws requires land shown on a plat to meet all health, safety and welfare requirements before it can be approved by the planning board. The section also includes additional requirements for streets and highways, monuments, zoning, parkland and residential units. The Zoning Board of Appeals can authorize an area variance for plats that do not comply with local ordinances, the Planning Board can waive certain requirements and a performance bond or other security can be furnished to the city by the owner as an alternative to the installation of infrastructure and improvements.