Mr McDonald said resource consent notification issues had been raised.
The other main issue was that an acoustic analysis had indicated that Meerkat's proposal needed further work, with potential cost implications.
Cr Guy complained that he had only learned by email from the Mayor Stuart Crosby last Thursday night that the consenting process had raised a number of hurdles - after Mr Crosby had spoken to a Bay of Plenty Times reporter that the number of electronic sirens needed to cover the 20km coastline would cost too much.
Mr McDonald said a full report on the sensible way forward would be prepared for the council by city engineer Howard Severinsen.
It would "properly traverse all the issues and solutions".
He said sirens were of high interest to the community and everything needed to be on the table in order to make an informed decision.
Cr Guy wanted the report to also set out how the council got into this situation, suggesting it needed input from others - not just staff.
Cr Guy did not ask how much the first stage of Meerkat's contract had cost ratepayers.