Categories Ministerial Decision Ministry of Regional Municipalities and Environment: Ministerial Decision 421/98 Issuing the Regulation of Septic Tanks, Soakaway Pits, and Holding Tanks 1998/421 421/1998 98/421 421/98 Post author By admin Post date November 30, 1998 You do not have a valid subscription to view this content, please view our pricing page to subscribe or login if you already have a paid account. Username or E-mail Password Remember Me Forgot Password Tags Ministry of Regional Municipalities and Environment ← Royal Decree 83/98 Amending Some Provisions of Royal Decree 64/83 Establishing the Omani Banking Institute → Royal Decree 90/98 Adopting the Organisational Structure of the Ministry of Social Affairs, Labour, and Vocational Training