The phrase "a long backlog" is correct and usable in written English.
It can be used to describe a situation where there is a significant amount of work or tasks that have not been completed or addressed.
Example: "Due to the recent surge in orders, we now have a long backlog of requests that need to be processed."
Alternatives: "a substantial backlog" or "an extensive backlog".
When it reopened, there was a long backlog of departing and arriving flights.
It is to be open to the public starting Monday, though there is a long backlog of reservations.
There is a long backlog in orders for specialized ethanol rail cars to ship the surplus production.
Mobile operators have a long backlog of technologies to sell, and many, such as picture messaging and videotelephony, have been coolly received by customers.
Since the terrorist attacks of 2001, the need for Americans with security clearances to work for the Pentagon and military contractors has soared, with a long backlog building up in the early years of the Bush administration.
(A woman filed her application for citizenship three months too early and, by the time she was told to file again, found herself at the end of a long backlog).
As a result, until the long backlog of visa requests for Mexicans clears, he cannot be employed in America.
According to a cardiologist brought in on an emergency basis to start reading the long backlog of tests in Harlem, approximately half were abnormal and 20 to 30percentt needed immediate medical care.
Indeed, I wrote a while ago about a very sensible plan led by the British government for reforming the court, starting with plans to tackle its appallingly long backlog of cases.
Environmentalists worry that loss of critical habitat will weaken protection, that the FWS's long backlog will result in harmful projects going forward, and that the compensation scheme would bankrupt the FWS.
Critical goals of the agency, such as reducing the unacceptably long backlog for pending claims, would have to be ignored further into the future.
