There are many ways to answer this question
If you mean will remediation of existing facilities that have suffered an adverse enviromental impact, there are two answers- yes and no.
The US and state governments generally do not allow a facility to escape their legal obligations when there is a recession.
But, that is subject to funding. And if the facility owner does not have the money to complete a project, then he will have to negotiate with the state/federal regulators.
What suffers is a companies committment to new projects that might reduce emissions, unless such projects can substantially reduce permit and/or disposal costs. For instance, if a factory had planned on installing scrubbers on various stacks, they may be likely to postpone the project until capital can justify the project.
In the meantime, the EPA will be headed by a democrat administration. While the administration will pay "lip service" to the special interest groups that got them elected, they may or may not institute new regulations that will ruffle the economy.
The Clinton administration did not pass any new regulations that were beneficial to the environment during the first few years of their term which was recessionary.