Septic Installation & Cesspool Conversion in Nanawale Estates

We install septic systems and convert cesspools in Nanawale Estates, roughly 20 to 25 minutes from our equipment yard in Keaau. Nanawale is younger ground than most of Puna. The subdivision is built on lava from 1840, not the centuries-old flows under the subdivisions closer to Keaau, and that shapes most of what septic in Nanawale involves.

Nanawale Estates Basics

  • Population: 1,652 residents in 595 households in the 2020 Census, up from 1,426 in 2010 and 1,073 in 2000.
  • Housing units: 625 in the 2010 Census.
  • Location: Hawaiian Beaches to the north, Pahoa to the west and the Nanawale Forest Reserve to the south. Hilo is about 20 miles north.
  • Elevation: about 420 feet at the census reference point.
  • Lots: two Nanawale Estates lot listings we read were 0.18 acre, about 8,000 square feet each.
  • Association: the Nanawale Community Association. Listings show modest annual dues and a mix of paved and dirt roads.
  • Lava hazard zone: Zone 2 where we checked it, on the State-hosted version of the USGS lava hazard map.
  • Lava under your lot: the 1840 lower Puna eruption, according to USGS.

Built on the 1840 Flow

USGS states it directly: “Nanawale Estates is built on the lava flow” from the 1840 eruption. That eruption began May 30, 1840 and lasted 26 days. Most of the activity centered just southeast of Pahoa, and lava reached the sea, building new coastline. A Lahainaluna School engraving from November 1840 shows lava entering the sea at Nanawale.

Lava that young has had little time to weather into soil. For comparison, the USDA describes the Opihikao soils mapped in the Puna district as just 2 to 10 inches of organic material and a little ash over pahoehoe. When the engineer’s test pit shows fractured rock, the leach field has to be built as a soil replacement system: we cut out rock and backfill until there’s 3 feet or more of fill between the effluent and the water table.

Small Lots on Young Rock

This is where Nanawale gets tricky. The state’s wastewater rule wants 10,000 square feet of land behind each system, and an 8,000 square foot lot falls short. The saving clause is the recording date: parcels recorded before August 30, 1991 aren’t held to that minimum. Puna’s subdivision lots date from 1958 to 1973, according to a district history, so many Nanawale lots may be covered. The engineer pulls your parcel’s record to be sure.

Even with the exception, a small lot leaves limited room for:

  • keeping the tank and leach field 5 feet off the house and the lot lines, or 9 feet if it’s a seepage pit
  • a catchment tank, if you have one
  • the disposal area itself, which on rock is dug out and rebuilt with fill

Put those together and an 8,000 square foot lot on young pahoehoe can be one of the harder layouts in Puna. Hawaii’s typical conversion range is $20,000 to $50,000, and a small lot on fresh rock pulls toward the expensive side. Our cost guide shows the breakdown.

Lots Near the Water or the Forest

Nanawale borders the Nanawale Forest Reserve to the south, and the 1840 flow it sits on runs down to the sea. If your lot is near the ocean, nothing in the system can sit within 50 feet of the certified shoreline. Low-lying ground close to the water may also leave less room above the water table. Your engineer measures that and picks the fix, whether it’s extra fill or an aerobic unit. There’s no rule that coastal Nanawale lots must have one.

On wooded lots, the question is usually clearing. We need a path for the excavator and room to work around the disposal area, so tell us what’s growing between the road and your cesspool.

Close Call in 2018

During the 2018 lower Puna eruption, lava from fissure 8 ran in a channel toward Kapoho, east of Nanawale. In June 2018 the USGS Hawaiian Volcano Observatory warned that lava could break out of the channels and threaten the community of Nanawale, which it counted at 675 homes and 1,384 residents. The lava kept spreading into Kapoho Beach Lots and the Four Corners area instead, and did not reach Nanawale.

What that means today:

  • Nanawale sits near the 2018 flow field, so it’s worth knowing your hazard zone before a large investment. The point we checked is Zone 2.
  • Kapoho, just down the coast, has its own DOH priority listing. The 2017 report flagged about 220 Kapoho cesspools for their effect on the Waiopae tide pools. Nanawale wasn’t named, but you can check your own parcel on the UH Cesspool Prioritization Tool. Our priority map guide shows how.

Roads and Access

Nanawale lot listings describe private roads, some paved and some dirt. On dirt roads, an excavator trailer and a tank delivery need dry weather and room to turn. We check your road on the first visit and schedule heavy deliveries around the rain.

Deadlines, Sewer and Paying for It

Hawaii gives every cesspool owner until the start of 2050 to get off the cesspool. The Health Department can move that up for a remodel that adds bedrooms, a cesspool pumped three or more times in a year, or one that overflows repeatedly. Nobody has been allowed to install a new cesspool since 2016.

The County’s 2022 Puna wastewater study listed Nanawale Estates only as a possible future location, subject to community review. It wasn’t among the ten communities identified first. Plan on an individual system unless the Department of Environmental Management tells you otherwise.

Ways to pay: the Hilo USDA office handles Section 504, which offers 1 percent, 20-year repair loans capped at $40,000 for very-low-income owners and grants capped at $10,000 for those 62 and over. See if you qualify. The state’s Act 204 loan program is expected to open late this year.

Lower Puna Neighbors

We also work in Pahoa, Hawaiian Beaches & Shores, Leilani Estates and the Kalapana area. Everything else in the district is on our Puna septic services page.

Get a Nanawale Estimate

Tell us your lot size, your road and how close you are to the water or the forest edge. We’ll come look at the rock and tell you what fits. Request a free estimate

Frequently Asked Questions

My Nanawale lot is about 8,000 square feet. Can I get a septic permit?

Possibly. The 10,000 square foot minimum doesn’t bind a lot recorded before August 30, 1991. Your engineer checks the record and whether the tank and field fit inside the setbacks.

Why is the rock in Nanawale so close to the surface?

Because the ground is young. USGS says Nanawale Estates is built on the 1840 lava flow, which has had little time to form soil.

Did the 2018 lava reach Nanawale?

No. USGS warned in June 2018 that lava could threaten Nanawale if it broke out of its channels, but the flow spread into the Kapoho area instead.

Is Nanawale part of the Puna sewer plan?

Only as a possible future location subject to community review, according to the County’s 2022 study. Check with DEM, but expect to need your own system.

Do I need an aerobic unit if my Nanawale lot is near the ocean?

Not automatically. Keep the system 50 feet back from the certified shoreline, and let the engineer’s groundwater measurement decide the treatment level.