Septic systems in Newcastle, OK

Newcastle is in McClain County, south of OKC across the Canadian River. City sewer covers part of town; a 2022 state funding request by the City said its commercially zoned area was still without wastewater service (Oklahoma Watch ARPA request record).

Local facts for Newcastle

• Inside city limits, owners on a street with a public sewer within 300 feet of the property line must connect within 60 days of official notice (Code section 53.03, Newcastle Code of Ordinances).
• Septic tanks are otherwise not allowed inside city limits, except where sewer connection is not required; then a septic, total retention lagoon or other DEQ-approved system may be used, and a successful percolation test is required before installation (section 53.04).
• Property outside city limits can connect to city sewer only after annexation and City Council approval (section 53.02).
• The City's trade permit schedule lists $100 for a new septic tank and $50 for a septic repair, plus a $4.50 state fee (adopted Apr 8, 2024, Newcastle Trade Permit Fees). This is on top of DEQ's own fees.

Tip: If you get a sewer connection notice in Newcastle, the 60-day clock starts from the notice; ask the City about timing before paying for a septic repair.

State rules

DEQ rules apply across McClain County: inspection before backfill, certified installers, and the 2-year aerobic maintenance rule (rules, aerobic guide). Local contact: City of Newcastle.

Costs

See the sourced cost table and what each service involves.

Local facts checked Oct 23, 2026.