text: **21.**—(1) Workers engaged in essential or emergency works— 
  (a) related to water supplies and sewerage services; and 
  (b) carried out by, for, or on behalf of a water undertaker, sewerage undertaker, water supply 
  licensee, sewerage licensee or local authority, 
  
  where they have travelled to the United Kingdom in the course of their work. 
  
  (2) For the purposes of sub-paragraph (1)— 
  
  (a) “essential or emergency works” includes— 
  
  (i) inspections, maintenance, repairs, and asset replacement activities, 
  (ii) monitoring, sampling and analysis of water supplies under the Private Water 
  Supplies (England) Regulations 2016(**a**), the Water Supply (Water Quality) 
  Regulations 2016(**b**), the Private Water Supplies (Wales) Regulations 2017(**c**), or the 
  Water Supply (Water Quality) Regulations 2018(**d**); 
  
  (b) “sewerage licensee” means the holder of a sewerage licence under section 17BA of the 
  Water Industry Act 1991(**e**); 
  
  (c) “sewerage services” has the meaning given in section 219(1) of the Water Industry Act 