Mound Septic System (circled) During King Tide - Oct 11, 2021. Windmill Point, Lancaster County, VA

SNAPSHOT: With increased flooding from sea level rise and more intense rainfall, septic systems are starting to fail. For rural areas this is forcing tough choices with significant consequences for residents and rural economies. There are no good outcomes but we’ve got to start addressing this issue because rural areas are facing a growing crisis as septic system failures increase.

A new Virginia law requires climate change impacts to be considered in septic permits and the Virginia Department of Health is figuring out how to do that. We’re the first state in the country to attempt this and it’s not easy. A work group has been meeting with a goal of producing new draft septic regulations by Fall of 2022.

But the reality is very complicated so, continuing our series of posts trying to put complex climate change adaptation policy issues “on the ground,” let’s examine a couple of sites in Coastal Virginia.

BACKSTORY: Let’s start with basics. You can only live in a house if you have a way to get rid of sewage, either through a pipe leading to a waste treatment plant (as happens in most cities and towns) or to an on-site septic system (as happens in more rural areas).

In the United States, 26 million households (about one-fourth of all households) use septic systems. In Virginia, about 1.1 million households use septic and in other coastal states, the numbers are high as well. In North Carolina about 48% of all households use septic and in South Carolina about 40% of households use septic.

There are basically two types of septic systems - conventional systems that cost in the range of $10-$20,000, or advanced onsite septic systems (AOSS), with costs in the range of $30-$40,000). Conventional systems use a drainfield to treat sewage effluent, requiring at least 18” of unobstructed dry soil beneath the drainfield to let the effluent flow through, allowing removal of bacteria and nutrient pollution.

Conventional Septic System with drainfield shown

Conventional septic systems are designed to last decades, 30 - 50 years, with proper maintenance. When conventional systems fail the current fixes are: replacement, [either with conventional septic, or advanced systems] or connection to sewage systems. For many coastal areas with increasingly soggy ground and in areas where soils won’t drain well, conventional septic will not work. In rural areas far from sewage utility pipes, connection to sewage systems is impossibly expensive.

Climate Change Impacts

As climate change brings more rainfall and rising tidal waters, these septic systems flood and fail. To illustrate these challenges of septic failures and climate change, let’s look at a site in rural Virginia. The residential lot we’ve selected is along a section of Windmill Point Road (state route 695) in Lancaster County, VA, at the point where the Rappahannock River flows into the Chesapeake Bay.

On a normal day things are fine. The picture below shows this area with the house’s advanced, mound septic system mound circled in red:

Advanced septic (red circle) on a normal day.

The mound system on this lot was installed in 2013 (replacing an earlier, conventional septic system installed around 1981) and met all the existing permitting requirements. The mound system gave the treatment field the vertical separation needed (18” of dry ground beneath the drain field) and the system was at least 70 feet from the high tide line (to prevent leakage of sewage or nutrients into surrounding waters.)

But the permits do not anticipate future conditions and with higher tides, the system is being regularly inundated, causing the pollution treatment capacity to fail, liberating bacterial and nutrient pollution from the flooded septic field.

On October 11, 2021, this region experienced a high tide event after a new moon, as a strong wind from the north stacked the water up. As a result the water was about 1 1/2 feet higher than the normal projected tide levels, producing “minor flooding.”

The Windmill Point tide station showed the water levels on October 11 in the chart below.

Flood tide level (green line) v. normal tide (blue line) for Oct 11 (in red circle). click for larger version.

The result of this minor flooding is shown in this drone photo taken Oct. 11, 2021. The circled septic system, a mound system, is barely above the flood water level but probably not fully functioning. The two properties to the right in this picture show no evidence of a mound system, meaning with even less flooding than this they have no functioning septic systems.

The situation in the picture above was repeated 9 times on higher tides in October, 2021, and 6 times in November, 2021, due to a series of fall “nuisance flooding” events. The resulting leakage of sewage into surrounding waters is a health problem but also an economic one: the oyster aquaculture sector in nearby creeks in Lancaster County brings in $16 million per year. When fecal bacteria are detected in oyster grounds, they are shut down for harvest until the water clears. Increasing septic failures are threatening the county’s emerging oyster harvest sector.

Flooding and Septic Systems

With sea level rise and increased rainfall intensity, we are seeing more threats to septic systems. When flooded by rain or tides, septic systems cannot function and release untreated sewage into surrounding waters, dumping bacteria and untreated nutrient pollution, and often causing sewage to back up into residences and businesses, eventually rendering structures uninhabitable.

The future impacts, as outlined in a recent publication by Virginia Institute of Marine Science staff, are dire: “With accelerating sea level rise, failing septic systems will become a significant stressor to individual property owners, and may force them to retreat from the coastline, disrupting communities and creating significant economic losses both to the relocating population and the deserted localities.”

In coastal areas, the rising tidal levels don’t need to cause flooding across the top of the ground to trigger septic failure. Much of the coastal shallow groundwater is tidally influenced and connected underground to the surrounding tidal water. When the tidal water rises, so does the groundwater, rising up into the septic field, compromising conventional septic systems or causing failure, as illustrated below.

Rising groundwater levels can cause septic failure

The only options left are the advanced onsite septic systems (AOSS) such as the mound system used in our Lancaster County example. However, in some areas, such as the property we’re looking at, even a mound system is insufficient in the face of higher water. Also, mound systems require pumps to move water up into the mound and during periods of power outrages these systems will fail, without generator backup (adding to the cost of an advanced system).

On a broader scale, flooding septic systems are an indicator of significant climate change impacts that call into question the future ability to live on these parcels. In very low lying areas such as the one in Lancaster County, the mound system may be above the frequent flood level, but eventually flooding on the property and its access roads will make living there impossible. In one respect, failing septic systems due to rising tidal waters and rising groundwater, are early warning signs of areas that will eventually be uninhabitable regardless of the sewage disposal problems. A projection of what this property in Lancaster County (indicated by red arrow) will look like in 2060, in these images provided by Old Dominion University :

Windmill Point in 2060 (property at red arrow).

With projected rates of sea level rise (~2’ by 2060), this property will be underwater most of the day, as will Windmill Point Road. At this point, the properties will be uninhabitable. This raises a whole other set of difficult decisions about whether new or replacement septic systems should even be allowed in this part of coastal Virginia.

These are some of the issues being discussed during the deliberations about how to regulate septic systems in the face of climate change.

Problems Reach Across the Coastal Region

The situation in Lancaster County is not an isolated problem. In Mathews County, on the next peninsula south of Windmill Point, is the community of Bavon. Along Willow Cove Lane, there are mound systems serving two properties.

Mound systems installed in Bavon, Mathews County. Phragmites is in foreground (tall plants with feathery ends).

These mound systems are bordered with phragmites, an invasive plant that shows up at the upper edges of tidal of wetlands, meaning these mound systems are in a very wet area.

Thee mound systems are so large, they can be spotted in Google Earth. The two septic mounds shown in the photo above are circled in red.

As with the systems in Lancaster County, these systems will begin to be increasingly inundated by 2060, when an additional 2 feet of sea level rise is expected. At that point, the mounds will be the “high points” in a flooded community. This image from the Old Dominion University viewer shows the entire community under water most of the time (dark and light blue) by 2060 with the septic mounds the only features poking above the water level, shown in light green.

Bavon in 2060, with the septic mound (green dot inside red circle) still peeking above the water.

This again illustrates how these advanced septic systems may allow people to continue to live in soggy areas, landscapes that we may need to begin retreating from in the near future. The longer-term consequences of keeping people on land that is going underwater is what the Virginia Department of Health is grappling with as they include climate change in septic regulations. But, as with all of our work on adaptation and retreat, there are no simple solutions.

“Grandfathered” coastal residences - what do we do?

People are living on land that will eventually flood due to past government decisions made: roads are constructed allowing people to settle near the water, septic systems are permitted and installed allowing them to live there, building and occupancy permits are issued, government underwriters back mortgages (VA, Fannie Mae, HUD, etc.) without regard to future conditions, flood insurance is available, etc. etc. Government for decades has enabled and encouraged people to settle on dry land that is now starting to flood. To be fair, until recently when these development decisions were made, we didn’t consider climate change: its only within the last few years that we had guidance specific enough to inform those decisions.

With climate change, we’ll need to start taking future conditions into account before taking these actions, but what are the consequences for people already there, living on Windmill Point or in Bavon?

When their conventional septic systems fail, property owners will ask to be allowed to install an advanced system or be hooked up to sewage systems. If sewage hookups are not available and the landowner is denied a replacement septic option, based on future conditions, is that a “takings?” In other words will government denial of a septic permit because of climate change impacts cause a landowner to lose the use and value of his/her land? Will this government decision “take” away the landowner’s right to continue to live on the land?

We can anticipate a number of lawsuits on this issue as we face a long and contentious period of change as we try to address these future conditions.

Environmental Justice

As the septic issue unfolds, it quickly becomes apparent that there are a number of environmental justice issues involved. Sewer hookups, when they are available, are expensive. The AOSS systems that are used when conventional septic systems fail cost at least twice as much as conventional systems. For people living on rural properties who are “land rich and cash poor,” these costs are prohibitive. Stories are starting to describe this dilemma.

There are government programs that can help with these costs but the use of public funds raises question about whether we want to continue supporting people to live on an increasingly dangerous landscape? In many areas, septic failures are a harbinger of loss of the entire residence in coming decades. In those cases where rising coastal waters are triggering septic failures, would it make more sense to buy these at-risk properties out and relocate residents, rather than spending $40,000+ on a new advanced septic system? But what is the equity in doing this when a higher income person facing the same decision down the creek CAN use his/her own funds to install an advanced system on their own and be allowed to stay in their home?

And there are numerous legacy justice issues. When many freed slaves settled on their land in Virginia after Emancipation, the good farmland that drained well was already taken, leaving marginal lands for the newly emancipated slaves. In many cases, these poorly draining lands are where septic failures are concentrated, meaning the impact of septic failure may be falling disproportionately on rural African Americans. This issue was explored in an unpublished paper prepared by Virginia Department of Health employees.

Other issues complicate the equity of solutions. For example, many rural properties have been inherited without probate and deeds being recorded, leaving no proof of property ownership. For government assistance programs, such as qualifying for septic replacement, this is a barrier because funds for septic can only go to the land’s legal owner. These “heirs” properties are disproportionately concentrated in the African American community. While efforts are being made to address this issue, it is still a big hurdle for many landowners.

Next Steps?

The impacts of climate change on septic systems is the rural equivalent of the “nuisance flooding” that gets a lot of attention in urban areas, where media outlets are concentrated. Except where this flooding is triggering septic failure, there is more than a nuisance involved - it is actually threatening peoples’ homes and causing a health and environmental problem. The solutions are expensive and complicated and quickly involve decisions on retreating from dangerous and unhealthful situations.

This issue needs much more attention and discussion than it is getting. We need to begin putting more resources toward the problem and paying close attention to he regulatory deliberations in Virginia on rewriting septic regulations.

More press on septic issues.

Bay Journal - “Septic system failures expected to increase in Virginia”

Washington Post - “Climate change is wrecking septic tanks”

Coastal Star - “Rising seas threaten wastewater systems”