Essroc Cement Corporation operates a cement plant in Clark County, Ind. For more than one hundred years, Essroc has burned coal to produce cement at the facility. In 2014, Essroc decided it wanted to switch from coal to liquid waste derived fuel (LWDF). LWDF is hazardous waste amalgamated from various sources. Essroc’s facility was in an area zoned M-2 which permits a variety of industrial uses including cement production.

In December 2014, Essroc sent a letter to the Clark County Planning Commission (planning commission) asking for a letter stating that Essroc’s operations were “permitted as a matter of right” and would remain so if it switched to burning LWDF. Essroc also sought assurance that burning LWDF would not require Essroc to seek rezoning to an M-3 hazardous waste disposal district. The Planning Commission issued such a letter in January 2015.

In reliance on the letter, Essroc sought to modify its Part 70 air permit and obtain a Resource Conservation Recovery Act permit for a hazardous waste treatment and storage facility. After the permit applications were submitted, a group of concerned citizens began opposing the project. The planning commission then revoked its original letter and determined that Essroc would be processing and storing hazardous waste at the facility and that such use required M-3 zoning.

Essroc appealed the second letter to the Clark County Board of Zoning Appeal which affirmed. Essroc then sought judicial review in the Clark Circuit Court which also affirmed. Essroc appealed and the Court of Appeals affirmed in Essroc Cement Corp. v. Clark Cnty. Bd. of Zoning Appeals, __ N.E.3d ___, No. 10A04-1709-PL-2199, 2019 WL 1716776 (Ind. Ct. App. Apr. 18, 2019).

Essroc first challenged whether M-3 zoning was required to burn LWDF. The court held that it was because burning LWDF did not fit into any of the permitted uses in an M-2 district. Storing, processing, and recycling of hazardous waste, however, is expressly permitted in an area zoned M-3. The court determined that burning LWDF involved storing, processing, and recycling hazardous wastes. The court also rejected the argument that burning LWDF was an “accessory use” to Essroc’s permitted M-2 use.

Although zoning boards are not generally permitted to revoke their own decisions, there is an exception if the zoning board makes an error of law. The court held that the Planning Commission made an error of law and thus properly revoked its original determination that M-3 zoning was not required. The court also declined to address the argument that the planning commission estopped from revoking the first letter because Essroc had spent $1.2 million in reliance on the first letter. That issue could not be considered on judicial review because estoppel was not an issue that was raised during the planning commission proceedings. The court also noted in a footnote that estoppel is not generally applicable against government agencies.