| Action | Amend Regulations to establish requirements for gravelless material and drip dispersal |
| Stage | Emergency/NOIRA |
| Comment Period | Ended on 2/26/2014 |
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35 comments
This is poorly coneived and implented set of regulations that serves only to validate a single private sector claim of product superiority. There is no scientific basis for the claims made that a sownsized system is more likely to function over a period of time.
VDH has no expertise in the evaluation or approval of materials or components. They have no capcity for testing and efficacy of this regulation is based on unsupported documentation provided by a manufacturer. There are other agencies and organizations that have as their reason for being, testing of components and processes.
NSF hasn't developed a standard for these types of units. Any approvals are based solely upon expectations and the manufacturer's unsubstatiated clains.
VDH has a miserable track record of following up and confirming that products approved by Guidance, Memorandum and Policy are as effective as claimed and as approved.
Person should ask for VDH to provide proof that they have the capacity, capabiliy and to determine if a product can deliver the performance defined by th manufacturer.
While not disagreeing that the units addressed in these Reguations have a use, it not apparent to long term educated practitioners that the proposed reductions in area for he onsite systems as allowed will in fact protect the homeowner from a premature failure from insufficent capacity.
The Board should interview the numerous soil evaluators and professional engineers who refuse to allow any reduction in area sizing for use of htese products. It would alos be interesting for the Baord to interview VDH filed staff who have been involved in the failure of systems using these products for a better understanding of how the manufacturer is cooking the books to show his prodiucts are better than others.
Additionally, some manufacturers do not agree with the reduced area guidlelines and will not warranty their products with the reduced absorption area allowed under these regulations.
It is blantantly obvious that the elected representative that mandated and approved the legislation requiring VDH to promulgate these regulations were carrying a torch for ht emanufacturer, not for the publics health or long term well being.
The Regulations specify some VERY MINIMAL standards when using chambers when enhanced flow distribution (EFD) is REQUIRED. However, the regulations do not appear to address instances where EFD is NOT REQUIRED but a designer actually provides EFD. Therefore, a designer might, for example, provide a 600 gallon dose at a rate of up to 84 GPM with no pipe in the trenches (assume typical 2" force main and 4 bedroom dwelling). This would be a ridiculous design and a recipe for a potential premature failure. The regulations should specify a maximum pump dose and a maximum pumping rate for chamber systems. I think chamber manufacturers would probably agree. This needs to be addressed.
Can a septic tank effluent GRAVEL drainfield sized at 400 ft2 be reduced by 15% down to a 340 ft2 gravelless drainfield?
Similarly, can a TL-2 or TL-3 GRAVEL drainfield sized at 320 ft2 be reduced by 15% down to a 272 ft2 gravelless drainfield?
For nearly the past last 20 years in Virginia, drip dispersal field footprints have been equivalent in size to low pressure distribution drainfield footprints. Drip field footprints were increased in size due to slope just as low pressure distribution fields were increased in size. The center-to-center spacing of low pressure distribution trenches is increase by 1 foot for every 10 percent of slope. Therefore, on a 25% slope, the center-to-center spacing of two-foot wide LPD trenches would be increased from 6' to 8' which is a 33% increase in dispersal area. The same 33% increase has been applied to drip dispersal fields. However, this regulation eliminates the slope correction factor which will dramitically decrease the size of a drip dispersal field footprint.
What empirical evidence was used to make this decision? It appears the Virginia Department of Health is making a major change with this regulation with no scientific basis to do so. This is no different than eliminating the requirement to increase the center-to-center spacing for trenches on slopes. Will VDH consider this?
Experiments are done for a reason. Drip was tested in a specific manner for nearly 20 years in Virginia. Apparently the experiment was successful. But now VDH is rescinding the drip GMP protocol and adopting this regulation which is significantly different than what was tested.
Eliminating the slope factor should be a 32.1-163.6 design decision made by a private sector licensed professional engineer. Where does 32.1-163.5 stop and 32.1-163.6 begin?
Please bring back the slope factor for drip dispersal.
Can VDH answer these questions?
1. In the past 12 years how many chamber system drainfields were installed in Virginia and how many of those failed?
2. In the past 12 years how many gravel system drainfields were installed in Virginia and how many of those failed?
3. How many practicing OSEs vs. chamber system manufacturers were on the TAC committee?
4. Why are there so many private sector OSEs who will not allow a reduction for chambers?
5. Why are there so many private sector OSEs who will not allow the use of chambers at all?
6. Why has all the negative anecdotal evidence regarding chambers been ignored?
7. Why does this regulation discriminate againsts gravel manufacturers?
Gravel has proven to be an excellent product. Please level the playing field and give the gravel manufacturers the same reduction.
Why are we forced to allow a design changes and the private sector licensees do not. I thought we all had the same requirements to comply with. This isn't right.
The proposed regulation is ignoring my rights as a designer. Legislature made everyone get a license and mine is no good. Don't force me to approve a products or allow someone else to change my design that I am responsible for. We shouldn't be a manufactures distributer.
I am writing as a citizen working for VDH. In my 26 yrs or experience, I have learned that smaller septic fields means less time to failure. With all my years of experience, I can not advise a homeowner to keep standard footprint when a contractor can change my permit.
Maybe the homeowner should be made to sign a waiver that they want this product so when it goes bad, I am not to blame for contractor choices.
private sector people get to choose, why can't the public sector ones? Do I have a differenct license?
This regulation is proof that manufactures finally figured out how to take complete advantage of the system. Forcing us to do this is wrong. let us do our job, not rely on contractors.
As a concerned owner and user for one of these systems, I would like to say no to changing the design. We had this done at our home in 2006. Within months, we began having problems. The company did come back and add additional area to our septic (which should have been there according to our permit) and we also paid to have that area installed. Talk to your licensed professional before you agree to any changes by your contractor. In our case, we were told that "these were the only systems being approved by the county".
I feel we were mislead by the county health department and our contractor. No one told us what the impacts making the septic design smaller would do and that it was the at the discretion of the contractor. How could the person responsible for the design not be able to stop this?
Why should the regulations mandate a inspection for drip systems? Is this because one of the sponsers of this nonsense charges almost $2000.00 for "their" start up inspection? This sets a bad precedent about disclosure to the process. Inspections should be detailed in the design so an owner understands what he/she is paying for.
At a minimum, VDH should publish the scientific documentation that warrants an across the board 25% reduction in sizing using gravelless. I understand the concept however I would like to see the track record of theses reductions actually working over a minimum of 10 years. As a private sector AOSE I rarely spec gravelless systems and I NEVER take a reduction. I've had two experiences with gravelless systems. Both times the installer used gravelless technology without designer permission.
1. EHS designed conventional; installer used chambers and took the reduction. EHS approved at inspection. Within a little over a year the system was blowing out the end of the trenches. The homeowners, due to lack of additional money and that they had signed a waiver and felt they were stuck with it, dealt with the failing system for a few years. They finally called us and we added the "left out" trenches plus one additional (used gravel in all) and they owners are having NO problems with the system (almost 2 years later). These were class II conventional soils.
2. AOSE designed conventional using land management; installer used chambers but did not take a reduction; system started failing within a couple months...blowing out of the dbox. These were very heavy Class III soils 80 - 90 mpi. They only way to get this system working again was to put it on time dosing. There are 100's of conventional systems using land management in that area and all are gravel and all are working just fine with standard dosing. Only this one, the only one using chambers, had problems.
Another thing that bothers me about this legislation is the lack of restrictions due to site and soil conditions. For example, what about a repair in nonconventional soils. Would it be appropriate to take a 25% reduction on a site with a very shallow water table (say anything less than 18") with a typical 18" install? What about this gravelless reduction combined with other reductions (for ex. water saving devices or TL-3 treatment).
I think more investigation into this arbitrary reduction needs to be done. More guidelines as to when it's appropriate to take these reductions. Remember, the only person that truly loses when these systems prematurely fail is the Home Owner.
Given GMP #116 was rescinded on the effective date of the Board's emergency regulations, 12/07/2013, what has become of VDH's requirement for manufacturer’s to warranty gravelless material? Suggest the proposed language be amended to include "non-degradable by wastewater effluent" under 12VAC5-610-930.F.2.e., as follows:
2. Gravelless material shall have the following minimum characteristics for general approval:
e. Gravelless material shall pose no greater risk to surface water and groundwater quality than gravel in absorption trenches. Gravelless material shall be constructed to maintain structural integrity such that it does not decay or corrode when exposed to sewage. Gravelless material shall also be constructed to maintain structural integrity such that it will be non-degradable by wastewater effluent.
Given GMP #116 was rescinded on the effective date of the Board's emergency regulations, 12/07/2013, what has become of VDH's requirement for responsibility resting with the person who designed the Substituted System or with the contractor who installed the system (in cases where a VDH permit is modified)? Suggest the proposed language be amended to include "withstand typical construction equipment and residential use loads without deformation, cave-in, subsidence, or collapse" under 12VAC5-610-930.F.2.f., as follows:
2. Gravelless material shall have the following minimum characteristics for general
approval:
f. Gravelless material shall have a minimum load rating of H-10 or H-20 from the American Association of State Highway and Transportation Officials or equivalent when installed in accordance with the manufacturer's minimum specified depth of compacted cover in nontraffic or traffic areas, respectively. All gravelless materials must be capable of withstanding typical construction equipment and residential use loads without deformation, cave-in, subsidence, or collapse.
Owners are going to be subject to potentially reducing the lifespan of an onsite system by "allowing" a contractor to "substitute" a system type. Owners should always insist that the construction bid should cover the Actual design as approved by the Regulatory Agency. Any modifications to the existing permitted system should be obtained in writing that explicitly declares what impacts, if any will occur to the "modified" system.
Given GMP #116 was rescinded on the effective date of the Board's emergency regulations, 12/07/2013, what has become of VDH's requirement for the owner to preserve and maintain the total area required and not disturb the area in any manner that will render it unusable? Suggest the proposed language be amended to include "must be supplied with observation or access ports" under 12VAC5-610-930.F., as follows:
F. Gravelless material is a proprietary product specifically manufactured to disperse effluent within the absorption trench of an onsite sewage system without the use of gravel. Gravelless material may include chamber, bundled expanded polystyrene, and multi-pipe systems. The division shall maintain a list of all generally approved gravelless material. Gravelless material on the generally approved list may be used in accordance with Table 5.4 of 12VAC5-610-950.
9. Gravelless systems must be supplied with observation or access ports, which allow for post construction inspection access to head off clogging events, and future access for cleaning out any sludge accumulation in the absorption trenches. Locate acces ports in or near the middle third of the trench and both upstream and downstream of the absorption area.
The proposed rulemaking is related directly to an effort to consolidate and codify several long-standing GMPs, under which thousands of gravelless drainfield systems have been installed since VDH first began allowing chamber system installations in 1987. Moving gravelless system management from policy to regulation meets the intent of 12 VAC 5-610-448.(A), which addresses codification of technologies that have been granted general approval under a VDH-issued policy. In addition to broadening the single option Virginians have historically had for constructing a drainfield under the regulations, the effort also opens the door to future innovation, allowing VDH to adopt new gravelless technologies under a flexible rule structure.
Benefits of Regulatory Change: The proposed rulemaking will consolidate requirements from GMP 127 and GMP 135 and move parameters such as a maximum 25% reduction into regulation. Infiltrator Systems supports the use a uniform 25% reduction for all soil percolation rates. Industry does not support what is referred to as double dipping, or taking a reduction as allowed for gravelless technology on top of a reduction associated with advanced treatment. In addition to consolidating GMPs, the maximum 50% reduction is eliminated from Virginia sizing options with the withdrawal of GPM 116. Industry believes that these collective changes represent a net improvement to the Commonwealth’s onsite wastewater treatment system regulatory framework. In addition, establishing a single method for sizing gravelless systems simplifies the use of gravelless products while adding a safety factor to designs.
Ubiquity of Gravelless Technologies: Proprietary gravelless drainfield products are approved in all 50 states and 10 Canadian provinces, with over 3 million systems installed over the past 25 years. Approximately 50% of the septic systems installed in North America each year are constructed at reduced sizing compared to stone and pipe systems using gravelless drainfield products. Proprietary gravelless drainfield products make up over 75% of all systems installed in 9 states. In 16 other states, proprietary products make up between 50 and 75% of all drainfields installed. The International Association of Plumbing and Mechanical Officials (IAPMO), allows a 30% sizing efficiency for gravelless technologies.
Third-Party Performance Studies: The use of a sizing reduction for gravelless products compared to the size of a stone and pipe drainfield is a proven method that is supported by independent research. Numerous statistically valid studies have been conducted on this subject, including the world’s largest onsite system field performance study conducted in North Carolina (see below). Large-scale field performance assessments on installed, real-life gravelless drainfield products offer the advantage of a large sample population, differing physiographic and climactic conditions, and a wide spectrum of wastewater flows from the dwelling. Taken as a whole, the weight of scientific evidence from these studies shows that the performance of reduced-size gravelless systems is consistent with that of “conventional” stone and pipe.
Hydraulics Research: The North Carolina Department of Environment and Natural Resources (NC DENR) conducted a field performance study on 900 systems in total, including 303 stone and pipe, 303 chamber, and 306 expanded polystyrene systems in 2005. Study systems ranged in age from 2 to 12 years, gravelless systems were installed at a 25% trench length reduction compared to the length of a stone and pipe system, and all were distributed uniformly within the coastal, Piedmont, and mountain physiographic regions. At a 95% upper confidence level, the NC DENR found no statistical difference in malfunction rates between stone and pipe and gravelless systems.
The North Carolina study is important relative to Virginia’s gravelless sizing policy because North Carolina’s trench bottom area is consistently smaller than Virginia’s, due to daily flow and loading rate policy. With similar coastal, Piedmont, and mountain soil textures between the neighboring states, sizing proven to function satisfactorily in North Carolina will function at least as well in Virginia. For instance, for a 3-bedroom home in a 50 mpi soil, the minimum 3-ft-wide gravelless trench length in North Carolina would be 180 ft, while it would be over 50% longer in Virginia at 284 ft. The additional length required in Virginia provides substantially more bottom area and sidewall for wastewater infiltration.
Longevity Research: Other studies have been conducted to examine gravelless system longevity and treatment capability. The University of Maine conducted a study on chamber systems at least 20, and up to 30 years in age. Regulatory agency records showed that, at a 95% upper confidence level, gravelless systems at a 50% sizing reduction compared to the sizing of a stone and pipe system outperformed stone and pipe relative to number of required repairs.
Treatment Research: The Colorado School of Mines conducted a treatment efficacy study on operating gravel and chamber systems aged up to 11 years. Percolate samples were analyzed from 1 ft beneath infiltrative surface for treatment performance, and effluent ponding was monitored in the chamber and gravel trenches. No significant difference was observed in hydraulic or treatment performance between the gravel and 50% reduced length chamber systems.
Numerous additional third-party studies have been conducted on gravelless technologies and are available upon request from Infiltrator Systems. If interested in reviewing these studies, please do not hesitate to contact me at 800-221-4436, and I can provide them to you.
GMP 135.A (December 12, 2013), GUIDANCE MEMORADEUM AND POLICY, regarding 12VAC5-610-955, pg. 2 Drip Dispersal
“Procedures: Designs for drip dispersal require the practice of engineering. Drip dispersal designs pursuant to Va. Code Section 32.1-163.5 must comply with the emergency regulations; otherwise a professional engineer (PE) can propose drip dispersal in accordance with Va. Code Section 32.1-163.6 and not adhere to the emergency regulations.”
12 VAC5-610 The Sewage Handling and Disposal Regulations is the “Prescriptive Regulation”. By definition, Drip Dispersal is not a “conventional” system and thus design / review is covered by CHAPTER 613 REGULATIONS FOR ALTERNATIVE ONSITE SEWAGE SYSTEMS as a 163.6 submission. Engineering criteria for LPD and now drip are in the 610 regulations. Current application (design) of treatment and dispersal under site and sizing criteria in 613 has evolved from the criteria, the approach in 610 regarding the concepts In ground, Shallow Placed, and Fill systems. Reference to those sections is is incomplete and at best cumbersome.
“12VAC5-613-40.E. All plans and specifications for AOSSs shall be properly sealed by a professional engineer licensed in the Commonwealth pursuant to Title 54.1 of the Code of Virginia unless such plans are prepared pursuant to an exemption from the licensing requirements of Title 54.1 of the Code of Virginia. All AOSS designs prepared by a professional engineer shall be reviewed by the department pursuant to § 32.1-163.6 of the Code of Virginia unless otherwise designated in writing by the professional engineer.”
12VAC5-610-955 B.3. “Except as provided by 12 VAC 5-613, drip systems dispersing septic tank effluent shall comply with the requirements of 12 VAC 5-610-594. Drip systems dispersing of secondary effluent or better require a minimum of six inches cover over the tubing. Cover maybe achieved by a combination of the installation depth and Group II or Group III cover or other approved materials over the drip field”
The first sentence should be removed. I suggest replacing with “Drip systems designed to disperse septic tank effluent require at least 12 inches of soil cover over the soil treatment area”
PE designs under 32.1-163.6 pursuant to the AOSS Regs (613), regarding STE must have an 18” separation to limitation from the point of application and a minimum of 12” cover. The AOSS regulations are silent as to depth of installation of STE and pretreated effluents.
Gravelless products will be reviewed and listed similar to treatment systems per 613 (the AOSS regulations). Why not have proprietary drip systems packages that meet the regulations be reviewed and listed?
Interestingly 12 VAC 5-610-950. Absorption area design. E.1., the requirement of 12” of cover has it’s basis in “frost” protection.
The amended language under 12VAC5-610-950.D.2. bases the minimum area requirement on the width of a trench excavation without knowing the amount "overdig" in that excavation. Suggest the following revisions as "highlighted" below:
D. Sizing of absorption trench area.
2. Area reduction. See Table 5.4 for percent area reduction when gravelless material or low pressure distribution is utilized. A reduction in area shall not be permitted when flow diversion is utilized with low pressure distribution. When gravelless material is utilized proposed, the design width of the trench excavation shall be used to calculate minimum area requirements for absorption trenches.
The amended language under 12VAC5-610-920 proposes to delete the soil-gravel or sand interface and replace it with point of effluent application to the soil absorption area. How might the language better describe the application of effluent to the area over which that effluent is being distributed? Suggest the following revisions as "highlighted" below:
12VAC5-610-920. Distribution methods.
The term distribution methods refers to the piping, flow splitting devices, gravel, and other appurtenances beginning at the point of flow splitting and ending at the soil-gravel or sand interface point of effluent application application of effluent to the soil absorption area. Two basic methods are considered:
By now everyone has heard how great these systems are in other states. It seems quite insincere that a manufacturer has used a loophole in state expectations to potentially promote personal gain. As it stands, the proposed regulations are going to require "zero" input from the licensed designer who works for VDH. As cozy as it seems, VDH employees are being forced to ignore competence and professional experience issues in designing conventional onsite septic fields that are to be replaced by these proprietary "options".
Both the Technical Advisory Committee and Sewage Handling and Disposal Advisory Committees voiced strong and consistent opposition in allowing anyone other than the licensed professional responsible for preparing the desing to make ANY changes. Exploiting VDH to enforce ministerial duties that are less than or in conflict with actual design requirements is not in the public's best interest.
Septic fields function when designed to provide: support to ground and traffic loading, voids for flow equalization, and a point of attachment for fixed film biomass which sees sewage effluent as food and reduces BOD. Chambers sometimes provide two of the three requirements. Some soils provide environments to sustain biomass, but this quality varies and can only be determined by an experienced evaluator. The homeowner can only be assured of functionality by an independent site assessment by licensed Onsite Evaluator who holds their interest in system longevity as a high priority. Long term results are enhanced by installation in adherence to design and regulation, successful 3rd party inspection and periodic maintenance.
The 2006 NC DENR study revealed that failed drainfields were 15% more likely to be constructed from chambers, or if expanded poly 23% more likely, than pipe and rock. This is the same Department which oversees Duke Power’s coal ash storage ponds in NC.
The General Assembly via HB1726 compelled VDH to convene a Technical Advisory Committee. VDH's TAC requested failure data, and inspection reports. Staff and manufacturer were in agreement that no relevant data has been collected revealing any cause for concern. Despite several localities prohibiting or restricting use of CBEP, (e.g. Loudon County) VDH staff has been prohibited from discussing case history or experience, and has been cautioned against advising homeowners considering their contractor’s product substitution proposal. These substitutions result in a foot print reduction without any commensurate changes in organic loading, flow distribution and monitoring. Indeed this product is the only case in which VDH staff may reduce a footprint without recording a variance or lien against the property.
The majority of failed systems in VA share one common ground, they were designed by staff which was prohibited by their employer from exercising design authority over contractor substitutions and commensurate area reduction. In some cases the installations were not promptly inspected and damaged by storm event or erosion. Owners were offered free designs for repairs, and materials under warranty, few if any received indemnification funds.
The Board of Health supported staff recommendations with minimal consideration of the product history. Secretary Romano delivered a product endorsement under GMP135A w/ appendix. As the single largest design firm her staff is compelled to utilize these products despite production by a sole manufacturer and only two nationwide distributors. By most standards this would be considered a monopoly, supported by a quasi-monopoly. The Secretary requires her staff deliver construction permits incorporating these products into every system which does not meet the area requirements of the Sewage Handling Design Regulations. The designer (if licensed) takes full individual responsibility for the design under their DPOR license which certifies competence.
The field of designers is concerned and surprised that the conflict of interests revealed within this process has not attracted the attention of the AG, or the press.
who pays for this in the end; the owner does! Indemnification will protect agency staff from any wrong doing or lack of guidance provided during the consultation for designing the septic design. Only the manufacturers win this game. The broke of unfunctioning system will be paid for by the consumer.
Based on my years of experience drainfields with chambers have a much higher rate of failure (with or without a reduction. The regulations should require an INCREASE in drainfield size when using chambers.
Why is EZFlow (or any other similar product) better than gravel? It's NOT. There should be a 1:1 substitution with this product.
It's amazing how we've completely lost all leadership in the health department. The manufacturers and private sector now run the sewage and water programs. I feel so sorry for the homeowners that get stuck with these products.
In the past I have kept my mouth shut and not bad-mouthed any proprietary products. Those days are over. I'm prepared to accept the consequences of violating the unwritten gag order.
Everyone knows that this is one of the dumbest regulations ever proposed. But what do you expect from an agency that has no leadership. Get over it. Yes, this regulation will hurt homeowners. There will be more malfunctions. And, we may need to boil our drinking water to be safe. Or, we can just move to a state that has better environmental leadership.
Give a 50% reduction for the use of gravel and then let's see what VDH does next when the gravelless manufacturers cry foul.
Proposed Text:
8. Gravelless material may be substituted for gravel in accordance with this chapter, provided that the certifying licensed professional engineer or onsite soil evaluator approves the substitution. The certifying licensed professional engineer or onsite soil evaluator shall identify the substitution on the inspection report submitted in accordance with 12VAC5-610-330. A new construction permit pursuant to 12VAC5-610-310 is not required for the substitution.
Recommended Changes:
8. Gravelless material may be substituted for gravel in accordance with this chapter, provided that the certifying licensed professional engineer or onsite soil evaluator approves the substitution in writing prior to system construction. The certifying licensed professional engineer or onsite soil evaluator shall identify the substitution on the inspection report submitted in accordance with 12VAC5-610-330. A new construction permit pursuant to 12VAC5-610-310 is not required for the substitution.
Justification: Per the Code of Virginia, only licensed professional engineers and licensed onsite soil evaluators may provide soil evaluations and designs for onsite sewage disposal systems. Likewise, any modification or alteration to the DESIGN may increase personal liability to the licensed professional who prepared the design.
Regulatory permits issued by the Virginia Department of Health do not require a license.
Proposed Text:
12VAC5-610-950. Absorption area design.
A. The absorption area is the undisturbed soil medium beginning at the soil gravel or sand interface which is utilized for absorption of the effluent. The absorption area includes the infiltrative surface in the absorption trench and the soil between and around the trenches when trenches are used.
B. Suitability of soil horizon. The absorption trench bottom shall be placed in the soil horizon or horizons with an average estimated or measured percolation rate less than 120 minutes per inch. Soil horizons are to be identified in accordance with 12VAC5-610-480. The soil horizon must meet the following minimum conditions:
1. It shall have an estimated or measured percolation rate equal to or less than 120 minutes per inch.
2. The soil horizon or horizons shall be of sufficient thickness so that at least 12 inches of absorption trench sidewall is exposed to act as an infiltrative surface; and
3. If no single horizon meets the conditions in subdivision 2 of this subsection, a combination of adjacent horizons may be utilized to provide the required 12-inch sidewall infiltrative surface. However, no horizon utilized shall have an estimated or measured percolation rate greater than 120 minutes/inch.
4. Any substitution that decreases the "Area Required per Bedroom" or "Area Required per 100 gallons" listed in Table 5.4 shall be supported by saturated hydraulic conductivity or percolation testing.
Justification:
The 25 percent reduction in area is removing a factor of safety established by the Virginia Department of Health. "http://www.vdh.virginia.gov/EnvironmentalHealth/ONSITE/gmp/documents/2010/GMP-035-dde.pdf".
If the proposed regulations are to start removing Agency factors of safety in the DESIGN of onsite sewage systems, then actual field test data should be an industry minimum to provide support for the removal of safety factors.
Recommendation
c. Placement and alignment. Pressure percolation lines shall be placed so that the holes face vertically downward upward except the distal hole. All pressure percolation piping shall be placed at the same elevation, unless throttling valves are utilized, and shall be level. The piping shall be placed in the horizontal center of the trench and shall maintain a straight alignment. Normally the invert of the pressure percolation lines shall be placed 8-1/2 inches above the trench bottom. However, under no circumstance shall the invert of the pressure percolation lines be placed closer than 16-1/2 inches to the seasonal water table as defined in 12VAC5-610-950 A 3. When the invert of the pressure percolation lines must be placed at an elevation greater than 8-1/2 inches above the trench bottom, landscaping over the absorption area may be required to provide the two inches of gravel and six inches of fill over the pressure percolation lines required in subdivision 7 a of this subsection.
Justification
This will help in limiting hydraulic scouring of trench bottom while allowing the line(s) to drain in freezing applications.
Table 5.4 conflicts with local ordinances for minimum sizing. owners may be subject to larger size septic fields that what this table allows. Our local ordinance has been tested for more years than these new systems
I have little to no confliect with the material covering drip technology. The systems have been well proven locally and nationally to be a viable and now reliable system. Technological advances with control systems have made the drip systems reliable and safe. I am not comfortable with some of the gravelless systems using open chambers in certain situtations and conditions.
I object to any unauthorized substitution of materails within any permit AOSE or PE derived; additionally the health departments issuing permits should be using licensed employees and grant the employee similiar latitude or accept the full responsibility for substitutions in code obsolving liability for the permit issuer.
I believe gravel substitutions have been widely accepted with past legislation specifically pipe bundled styrofoam peanuts and tire chips. I see absolutely no reason they should be granted any reduction in footprint unless the reduction is given for gravel and pipe. I'm sure its very possible to produce a pipe replacement system that can provide more biological treatment but I've yet to see one thats been proven.
My primary concerns with chamber systems are the lack of pipe (splash plates are a unacceptable in my opinion) within the trench with pump systems, dosing volumes equal to gravel are excessive, and the installation of chambers in various soil classes, specifically soils with high mica content.
It is my belief the chamber systems work very well in many soils with gravity flow systems. I don't feel there has been enough hardline data collected from the state and complied by the state to permit the proposed reduction in footprint that essentially strips all of the built in safety factor. I want to see more data collected from systems installed in a variety of soils within the state of Virginia from West to East including Valley and Peidmont soil not just coast plain. Maybe the reduction in footprint should require a physical water or K-Sat test to insure the entire area of install is suitable (not an average rate across a large site).
As a designer and AOSE I don't perscribe systems with a one size fits all approach, I would be a fool to do so. No one system will work under all the conditions found in my area. I don't feel chambers have the ability to be used in every soil condition and in every design situation. I strongly object to any contractor or installer substituting ANY product without the explicit and written consent of the AOSE/ designer or VDH employee. The VDH employee issuing a permit (who should be DPOR licensed) is accepting responsiblity for that system and should have the right to determine exactly what can be used in its construction.
There have been enough failures reported to be associated with gravelless chamber systems to warrant the state to examine all facts and data on the installed and functioning systems and failures to determine if this is a real threat to public health or a rumour. The information is available from Virginia local health departments (Venus, Carmody, RME) and manufacturers, its important to look at the data from both entities as it relates specifically to Virginia and the various soils, conditions and environments in Virginia. A thorough examination of the data still requires field work to check the longterm viability of these alternative products, field study must not be left out. The Great State of Virginia has spent millions of dollars requiring the data collection of alternative systems, now is a good time to put that money to use and help make an educated decision that truly serves the taxpayers, environmental and public health.
VDH must have a great deal of faith in these gravel replacement products to require their OSE's to add the statement to all permits that gravelless material may be used in accordance with Table 5.4 (reductions). This decision should involve the permitting VDH OSE and a homeowner who has had the opportunity to be educated regarding the choices-particularly when it comes to reducing area. The contractor is given a blanket "go ahead" to make the decision to use the material of his choice, but will be relieved of responsibility for that choice. Who is running the show here? The contractors... the manufacturers?
I started designing with chambers years ago when they first publsihed the GMP, and my GMP 135 systems are still working today. There is lots of opposition to the rules that came from that house bill last year, but its worked here in the Richmond area over the long haul. I stay the course.