(1) Sixty-six percent or more of wastewater measurements taken during a six-month period exceed the discharge limits for the same pollutant parameter by any amount;

(2) Thirty-three percent or more of wastewater measurements taken during a six-month period equal or exceed the product of the daily maximum limits or the average limits multiplied by the applicable criteria established by federal guidelines;

(3) Any other discharge violation the city believes has caused, alone or in combination with other discharges, interference or pass-through (including endangering the health of city personnel or the general public);

(4) Any discharge of pollutants that has caused imminent endangerment to the public or to the environment or has resulted in the city's exercise of its emergency authority to halt or prevent such a discharge;

(5) Failure to meet, within 90 days of the scheduled date, a compliance schedule milestone contained in a permit or enforcement order for starting construction, completing construction or attaining final compliance;

(6) Failure to provide, within 30 days after the due date, any required reports, including baseline monitoring reports, 90-day compliance reports, periodic self-monitoring reports and reports on compliance with compliance schedules;

(7) Failure to report noncompliance; or

(8) Any other violation which the city has reason to believe is significant.