The Central Pollution Control Board (CPCB) is a statutory organization in India that functions under the Ministry of Environment, Forest, and Climate Change. Its primary responsibility is to promote cleanliness of streams and wells in different areas of the States by preventing and controlling water and air pollution. Let's examine each option to identify the function that does not fall under the scope of the CPCB:

(1) To collect data relating to water pollution: This is a crucial function of the CPCB as it helps in understanding the extent and impact of water pollution in different parts of the country.

(2) To lay down standards for sewage and emissions: Setting and enforcing standards for sewage and emissions are important functions of the CPCB to regulate and control pollution levels.

(3) To organize cleanliness drives to clean water and land: While cleanliness drives are essential for maintaining a healthy environment, they are not explicitly mentioned as a primary function of the CPCB. Such activities may fall under the broader initiatives of the government or other related organizations.

(4) To organize comprehensive mass awareness programs against pollution: While raising awareness about pollution and its impact is crucial, this function may not directly fall under the specific responsibilities of the CPCB, as its primary role is to regulate and control pollution through data collection, setting standards, and monitoring compliance.

Based on the analysis, the function that does not align with the primary role of the CPCB is (3) To organize cleanliness drives to clean water and land.