▁industrial ▁zone . ▁In ▁ 1 8 7 0 , ▁the ▁authorities ▁suggested ▁that ▁past ure ▁lands ▁to ▁the ▁east ▁of ▁the ▁city ▁be ▁all otted ▁for ▁construction ▁of ▁oil ▁ref iner ies . ▁By ▁ 1 8 7 2 ▁there ▁were ▁almost ▁si xty ▁ref iner ies ▁in ▁B aku ▁producing ▁k eros ene . ▁A ▁law ▁was ▁passed ▁prohib iting ▁construction ▁of ▁any ▁new ▁plants ▁in ▁the ▁city , ▁and ▁alloc ating ▁a ▁new ▁district ▁outside ▁the ▁city ▁limits ▁for ▁ref iner ies . ▁ ▁Foundation ▁and ▁growth ▁ ▁By ▁ 1 8 7 4 ▁there ▁were ▁ 1 2 3 ▁ref iner ies ▁in ▁what ▁would ▁become ▁known ▁as ▁" Black ▁City ". ▁The ▁ref in ery ▁district ▁was ▁about ▁ ▁from ▁the ▁sh ipping ▁ports . ▁An ▁industrial ▁area ▁plan ▁was ▁completed ▁in ▁ 1 8 7 6 . ▁Some ▁of ▁the ▁far ms ▁and ▁past ures ▁of ▁the ▁neighbour ing ▁village ▁of ▁K esh la ▁were ▁z oned ▁to ▁accommod ate ▁rep lac ements ▁for ▁fact ories ▁that ▁had ▁been ▁dis m ant led ▁in ▁the ▁city . ▁The ▁new ▁industrial ▁zone ▁was ▁ ▁from ▁resident ial ▁areas . ▁To ▁prevent ▁further ▁poll ution , ▁the ▁new ▁z oning ▁law ▁prohib ited ▁oil ▁ref iner ies ▁from ▁being ▁built ▁within ▁the ▁resident ial ▁area . ▁By ▁ 1 8 8 0 , ▁there ▁were ▁ 1 1 8 ▁industrial ▁business es ▁function ing ▁in ▁the ▁Black ▁City ▁area . ▁ ▁Most ▁of ▁the ▁B aku ▁oil ▁workers ▁lived