Compare actual private-facility and public-sewer connection quotes across initial work, annual operation, major repairs, present value, and equivalent annual cost.
No national average price is supplied. Enter authority-confirmed facts and like-for-like written quotes.
Law and method sources checked 2026-08-23. The synthetic example explains the math and is not market data.
Enter parcel-specific treatment-area, connection, and sewage facts, then apply one horizon and economic basis to both alternatives.
Confirm the parcel with the competent city, county, or district sewer office.
Used to discount future nominal costs.
Applied to annual and future major-repair cost.
Use the authority-confirmed value for the building use and size.
Increase caused by construction, extension, or change of use.
Use the designer- and authority-confirmed capacity.
Drawing distance from the public connection point to the building.
Combine the unit with design, excavation, piping, restoration, electrical work, and any closure scope.
Align the unit, internal equipment, delivery, and lifting scope.
Confirm drawings, drainage plans, inspection, and any resubmission allowance.
Use a site quote for soil, groundwater, rock, shoring, and anti-flotation work.
Confirm inlet, outlet, manholes, venting, and commissioning.
Separate concrete, asphalt, pavers, yard, and landscape restoration.
If gravity flow is unavailable, confirm pumps, controls, power, and standby needs.
Include sewage and sludge removal, removal or sealing, and the closure filing.
Align VAT, equipment access, temporary works, and contingency.
Combine the private drain, public tap, road restoration, old-facility closure, and authority-assessed contribution.
Confirm materials, quantities, design, contractor, restoration, and completion inspection.
Separate private land, roadway, rock, buried utilities, and shoring.
Confirm ownership, diameter, gradient, and manhole quantities across the boundary.
Confirm the connection point, tap or branch, public-asset restoration, and inspection.
Include occupation and excavation permits, traffic control, pavement cutting, restoration, and warranty.
Obtain professional design if invert levels prevent gravity flow.
Confirm Rule Article 28 cleaning, removal or sealing, and filing scope.
Enter only the amount confirmed under the local ordinance, not a national rate.
Align VAT, survey or utility detection, temporary drainage, and contingency.
Scenario basis: 2026, 15 years, 3% discount rate, and 0% cost escalation.
Comparison status
0/2
Lower present value
Awaiting confirmation
Present-value gap
KRW 0
Cost crossover
None in horizon or unconfirmed
Major-repair years: 2031, 2036, 2041
8 initial scopes remain unconfirmed
Major-repair years: 2036
9 initial scopes remain unconfirmed
| Cost measure | Private treatment alternative | Public sewer connection | Private minus public |
|---|---|---|---|
| Initial cost | KRW 0 | KRW 0 | KRW 0 |
| Nominal annual-cost total | KRW 0 | KRW 0 | KRW 0 |
| Nominal major-repair total | KRW 0 | KRW 0 | KRW 0 |
| Nominal lifecycle cost | KRW 0 | KRW 0 | KRW 0 |
| Present-value lifecycle cost | KRW 0 | KRW 0 | KRW 0 |
| Equivalent annual cost | KRW 0 | KRW 0 | KRW 0 |
The facility type and connection duty cannot be assessed before the area, sewer type, and daily volume are confirmed.
The general facility review point is 2 m³/day, and the Article 61(1) contribution screen is an increase of 10 m³/day. Neither is a final determination.
| Year | Private nominal | Private cumulative PV | Public nominal | Public cumulative PV |
|---|---|---|---|---|
| 2026 initial | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2027 (year 1) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2028 (year 2) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2029 (year 3) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2030 (year 4) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2031 (year 5) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2032 (year 6) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2033 (year 7) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2034 (year 8) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2035 (year 9) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2036 (year 10) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2037 (year 11) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2038 (year 12) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2039 (year 13) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2040 (year 14) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
| 2041 (year 15) | KRW 0 | KRW 0 | KRW 0 | KRW 0 |
Law basis: Sewerage Act Articles 27, 34, 37, 38, and 61; Decree Articles 22, 24, and 35 and Schedule 1-6 (serial 18137675); and Rule Articles 22, 23, 27, 28, 30, and 31. Results never override local ordinances, notices, site design, or actual assessments.
A private sewage facility proposal may lead with the tank or treatment unit price. A public-sewer proposal may lead with a pipe or tap price. Neither headline necessarily includes design, filing, inspection, excavation, spoil removal, private drains, manholes, pavement restoration, electrical controls, pumps, closure of the old facility, public charges, tax, or long-term operation.
This calculator puts a new or replacement private sewage facility and a public-sewer connection on one scope. It compares initial cash, nominal lifecycle cost, present value, equivalent annual and monthly cost, major-repair years, and a cumulative-cost crossover. Every market cost starts at zero because Korean site conditions and local rules vary too much for a defensible national default.
This is a planning aid, not a determination of the legally required facility, connection duty, filing acceptance, design capacity, construction compliance, or originator contribution. Local notices, ordinances, site design, written assessments, and competent-authority decisions always control.
Public-sewer connection is not merely an optional upgrade selected because its lifecycle cost is lower. First confirm the treatment and drainage area, whether public-sewer service has commenced, the separate or combined sewer arrangement, the approved connection point and invert level, private-land and road crossings, and whether gravity flow is feasible. If the authority confirms that connection is unavailable, the calculator keeps the arithmetic visible but does not treat the public option as comparison-ready.
An unknown authority status is useful information rather than a reason to invent a value. Enter provisional quotes if needed, read the generated consultation questions, and return after the city, county, or district and the designers have confirmed the common project basis.
The private-drain distance is recorded as a quote condition; the calculator does not multiply it by a generic unit price. Thirty-eight metres through an open yard is not equivalent to thirty-eight metres through rock, a public road, a congested utility corridor, or land without equipment access. Require every bidder to price the same endpoints and restoration standard.
| Scope group | Private facility | Public connection | Review point |
|---|---|---|---|
| Design and filing | Facility plans, installation or change filing, completion | Drainage plans, connection filing, completion | Before contract |
| Earthwork and drains | Base, excavation, spoil, inlet and outlet | Private drain, manholes, public tap and branch | After survey |
| Restoration and power | Yard or landscaping, pump and controls | Road permit, pavement, pump and controls | After drawing |
| Old-facility closure | Removal or compliant closure during replacement | Cleaning, removal or sealing, and closure filing | Before works |
| Charges and operation | Tax, transport, cleaning, power, inspection | Contribution, fees, tariff, private-drain upkeep | Authority check |
A zero amount is not automatically missing. It may mean included elsewhere, reused, owner-supplied, not applicable, or forgotten. The separate scope checkboxes therefore matter as much as the amount. Mark one only after the proposal states included, excluded, separately priced, or provisional and identifies the VAT basis and rates for variations.
Initial costs occur in base year zero. Annual operation occurs in each year and grows at the entered nominal escalation rate. A major repair occurs at every multiple of its confirmed cycle through the selected horizon. Each future amount is discounted to the base year and added to initial cost.
annual cost in year t = base annual cost × (1 + escalation)t-1
major repair in year t = base repair cost × (1 + escalation)t
present value = nominal cost in year t ÷ (1 + discount rate)t
equivalent annual cost = present value × capital recovery factor
At a zero discount rate, equivalent annual cost is present value divided by the horizon. The crossover year is the first year in which the sign of the cumulative present-value gap changes. No crossover within the horizon does not prove that one option is universally better; it describes only the entered period and assumptions.
A lower number is not labelled a completed comparison until both alternatives have confirmed written quotes, annual costs, major-repair assumptions, and every initial scope, and the authority status makes both alternatives available for comparison.
The optional sample is fictional and exists only to verify the mechanics. Both escalation and discount are zero. The private option has KRW 15,000,000 initial cost, KRW 600,000 annual cost, and a KRW 2,000,000 repair every five years. The public option has KRW 25,000,000 initial cost, KRW 200,000 annual cost, and a KRW 1,000,000 repair every ten years.
Private option, 15 years
KRW 30,000,000
Public option, 15 years
KRW 29,000,000
Cumulative direction changes
Year 15
Private cost is KRW 15,000,000 initial, KRW 9,000,000 for fifteen annual charges, and KRW 6,000,000 for repairs in years five, ten, and fifteen. Public cost is KRW 25,000,000 initial, KRW 3,000,000 for annual charges, and KRW 1,000,000 in year ten. These values are not Korean market benchmarks, quoted prices, or a recommendation.
Sources were rechecked through the Korean National Law Information open API on August 23, 2026. The Sewerage Act is ID 001815, master text 276803, effective October 1, 2025. Its Articles 27, 34, 37, 38, and 61 provide the principal context for drainage connection, private-facility installation and changes, completion inspection, qualified design and construction, and originator contributions.
The Enforcement Decree is ID 005369, master text 286151, effective June 3, 2026. Articles 22, 24, and 35 and Schedule 1-6, serial 18137675, inform the drainage filing, important-change, general daily-volume, facility-standard, and contribution review signals. The Enforcement Rule is ID 008578, master text 287447, effective June 22, 2026. Articles 22, 23, 27, 28, 30, and 31 inform drainage documents, connection standards, private-facility filings, closure work, and completion procedures.
Outside a sewage-treatment area, the Decree contains a general 2 m³/day boundary used to prompt review of a sewage-treatment facility or septic tank. Special environmental areas and the actual sewer arrangement can change the analysis, so the calculator never decides the required facility. The 10 m³/day increase is a screen associated with Sewerage Act Article 61(1) and Decree Article 35; it does not prove exemption below that amount because other works, development activity, local ordinances, and actual assessments may still matter.
Enforcement Rule Article 28 is also important when an old facility is closed: confirm removal of sewage and sludge, physical removal or sealing against renewed inflow, supporting documents, and surface reinstatement. Put those tasks into the quote rather than assuming that a sewer tap price includes them.
Check old contents and unit removal, foundation and buoyancy work, inlet and outlet levels, pump controls, backfill, and yard restoration. Replacement of the body may be an important change under the Decree, so confirm change filing and completion sequencing before work begins.
Road occupation, traffic management, pavement cutting and reinstatement standards, the public tap, buried services, and working-hour restrictions may matter more than a simple per-metre pipe rate. Obtain the approved connection drawing before accepting a total.
A higher public-connection initial cost may be offset by avoided cleaning, power, inspection, repairs, or renewal, but public service charges, pump electricity, and private-drain maintenance are not automatically zero. Test the actual holding period and rerun discount and escalation assumptions before relying on the ranking.
No. It is a general review signal outside a treatment area, not a final classification. Confirm the area, sewer type, special environmental status, building facts, and authority interpretation.
No. The screen does not exclude other works, development activity, local formulas, or another lawful assessment. Enter only the amount confirmed by the authority.
Yes, after a written proposal confirms that it is included elsewhere, reused, owner-supplied, or not applicable. Zero without a scope answer remains ambiguous.
Use one internally consistent nominal basis for both alternatives and keep the assumptions with the decision record. Rerun reasonable downside and upside cases when no organisational benchmark exists.
No. That calculator plans recurring cleaning dates, local cleaning charges, and penalty references for an operating facility. This page compares capital projects and their long-run costs.
Put the parcel, building use, confirmed daily volume, approved connection point, invert, private-drain distance, and closure requirement on one project brief. Copy every initial scope line into both quote requests and require included, excluded, separate, or provisional status plus the VAT basis. Ask the authority for the filing, completion, road-restoration, connection, and contribution sequence. Only then compare present value and equivalent annual cost and retain the assumptions with the written decision.
The useful result is not merely the lowest number. It is a visible list of costs and responsibilities that would otherwise appear after contract signing.