Arkansas Administrative Code › Agency 007 - ARKANSAS DEPARTMENT OF HEALTH › Division 04 - Environmental Health Services › Rule 007.04.93-005 - Alternative Systems Manual

Current through Register Vol. 49, No. 6, June, 2024
GENERAL POLICY REGARDING ALTERNATE SEHAGE DISPOSAL
				SYSTEM CONSTRUCTION
As mandated by Act 402 of 1977, the Division of Environmental
				Health Protection, Arkansas Department of Health (ADH), encourages studies and
				submission of plans for alternative methods of treating and disposing of wastes
				generated by individual residences. However, the ADH is not obligated to accept
				or approve any system which would pose a threat to the health and safety of the
				citizens of Arkansas. The.concept, applicability and construction requirements
				of each alternate system proposed will be reviewed on a case by case basis. All
				alternative systems are considered to be experimental and will not be approved
				as a uniform plan of development in any municipality, community, subdivision,
				or other developed area. The ADH's acceptance and approval of an alternative
				design does not release the homeowner from any obligation, responsibility or
				liability relating to the system's operation and maintenance or any discharge,
				planned or unplanned. Also, ADH approval in no way constitutes a guarantee that
				the system will function as designed.
No alternative or experimental project will be considered if
				site and soil conditions indicate a standard septic tank/soil absorption system
				is feasible. Systems using subsurface absorption are preferable to surface
				discharges except in situations where groundwater quality would be
				jeopardized.
When the permeability of the ground strata is such that
				subsurface disposal by a conventional septic tank system is absolutely
				unacceptable, consideration will be given to an individual home treatment
				scheme with a surface discharge. Sewage discharges, however, may not be
				approved in subdivisions, built-up areas, or other critical high-use areas.
				Only sites demonstrating sufficient isolation from the populace and providing
				an acceptable location for a surface discharge will be considered. For proposed
				or newly constructed residences, a minimum lot size of three (3) acres is
				required. This should allow enough area for the system's effluent to remain
				on-site. Off-site discharges will only be considered on residences with
				existing, failed sewage disposal systems. All off-site discharges will also
				require a National Point Discharge Elimination System CNPDES) Permit issued by
				the Arkansas Department of Pollution Control and Ecology (ADPC&E).
PLAN REVIEW PROCEDURE
All plans for alternative and experimental sewage treatment or
				disposal systems serving individual residences are reviewed by the
				Environmental Program Services (EPS), Division of Environmental Health
				Protection staff. All plan specifications and ancillary information must be
				submitted in triplicate and a $30 plan review fee is required. Only currently
				licensed Designated Representatives and Sanitarians, employed by the Arkansas
				Department of Health, may submit plans. Each application must be accompanied by
				a statement as to why a conventional septic tank/soil absorption system is not
				feasible and a site evaluation submitted by the Local Sanitarian or Program
				Specialist.
Guidelines for Plan Submissions are provided by EPS and are
				periodically updated. In addition to the plan review fee, the following items
				are required in triplicate:
1.
			 Completed Application for Individual Sewage Disposal System
2. Plot plan and profile
3. Technical specifications
4. Vicinity map
5. Maintenance contract (Mechanical Treatment
			 Plants only)
6. Memorandum of
			 Agreement signed by the owner.
An outline of the alternate system review procedure is as
				follows:
1. After determining that a
			 conventional system is not feasible, the Designated Representative and an
			 Arkansas Department of Health representative decides which Cif any) alternative
			 system is most appropriate. Since the homeowner is responsible for paying for,
			 operating, and maintaining the system, they should be included in this
			 decision.
2. The Designated
			 Representative then compiles the application package following the Guidelines
			 for Submission of Plans for Alternate Sewage Disposal/Treatment Systems CR
			 & R 70 Rev.). The application package along with the $30 permit fee is
			 submitted to the local Health Unit. The County Sanitarian or Program Specialist
			 provides a site evaluation form and a copy of the permit fee receipt to be
			 included in the application package. The application package is mailed to:
Environmental Program Services
Division of Environmental Health Protection
Arkansas Department of Health - Slot 29
4815 West Markham
Little Rock, Arkansas 72205
3. The EPS staff reviews the application
			 package and either approves or rejects the submittal. If approved, the
			 homeowner's set of plans is returned to the Designated Representative, the
			 local Health Department copy is sent to the County Sanitarian, and one copy is
			 retained for the Central Office file. If the submittal is rejected, all copies
			 of the application package are returned to the Designated Representative along
			 with a letter listing the reasons for rejection and the procedure for
			 re-submitting the application.
All alternative/experimental sewage systems must be installed
				by a licensed septic tank installer. Homeowners may not install their own
				alternative/experimental system. Installers may be required to attend special
				training sessions (provided by the Health Department) before being allowed to
				install certain types of alternative/experimental systems.
The Health Department may require the Designated
				Representativeto.oversee the construction of projects withunusualor rarely used
				designs.
SOIL ABSORPTION SYSTEMS
Soil absorption systems are designed to infiltrate pretreated
				or conditioned sewage into the natural soil found at the disposal site. The
				pretreated or conditioned sewage then undergoes final renovation in the natural
				soil itself. The type of soil absorption system selected is determined by the
				limitations imposed by the soil, groundwater features and site location. Soil
				absorption systems are designed to have NO discharge of sewage to the ground
				surface. Protecting groundwater from sewage contamination Is a prime concern
				with soil absorption systems. No disposal scheme that has the obvious potential
				to contaminate groundwater will be considered.
Soils vary in wetness and seasonal water tables vary during the
				year. Soil absorption designs must account for wet conditions normally
				encountered in the late winter and spring. Applications are expected to present
				data on the soil type, texture, slope, and depth to rock or the seasonal water
				table. The depth to the seasonal water table (perched or apparent) may be
				determined either by the presence Cor absence) of chroma 2 mottling or by
				actual measurements conducted during the four wettest months of the year. Data
				from the Soil Conservation Service soil manuals is also helpful.
CAPPING FILL SYSTEMS
A capping fill is a modification to a soil absorption system
				used when the effective sidewall (gravel) of the disposal trench is Installed
				within 6 inches of the natural soil surface. A capping fill consists of a layer
				or cap of permeable soil positioned above a shallow absorbtion bed. This
				maintains the separation between the absorption trench bottom and the limiting
				layer and provides an adequate cover over the absorption bed.
The limiting layer can be either bedrock or a seasonal water
				table. The soil separating the trench bottom and the limiting layer can be no
				finer than a sllty clay loam. The slope of the absorption site cannot exceed 12
				percent. Submitted plans must indicate both the original and the finished
				contours.
The disposal site and borrow site must be scarified to destroy
				the vegetative material. Stumps should be left in place at the disposal site to
				prevent extensive disruption of the soi1.
The fill must extend a minimum of 10 feet beyond the edge of
				the absorption field. The fill area must be seeded and watered regularly to
				prevent erosion.
The fill material used must be a uniform loam or sandy loam
				with a maximum clay content of 27 percent. A minimum of 10 inches of settled
				fill must cover the absorption area. The depth of fill above the original
				ground surface is measured after settling. Loam and sandy loam soils can be
				expected to settle from 20 to 25 percent.
Inspection ports must be provided at the end of the first and
				last absorbtion trenches on a level ground system and every other absorbtion
				trench on sloping ground systems.
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SAND-LINED TRENCHES
Some soils encountered in Arkansas are limited in their use
				with conventional septic systems due to excessive permeability or poor
				filtration characteristics. The sand lined trench (SLT) concept is intended to
				enhance the renovation by filtering, slowing down, and spreading the septic
				tank effluent prior to introducing it into the natural soil. This should
				prevent a "spot loading" situation that could jeopardize groundwater quality. A
				SLT design should be considered on sites demonstrating a percolation rate of
				less than 10 minutes per inch or soils with a high stone content with little
				clay.
The basic components of an SLT system are the septic tank, the
				distribution system, and the filter bed. The septic tank requirements are the
				same as with a standard system though special care should be taken to insure
				that the tank has no holes, cracks, or other leaks that would allow the sewage
				to bypass the treatment scheme.
The distribution system consists of a properly constructed dose
				chamber, an acceptable pump or siphon, and either a distribution box or
				pressure manifold. Serial distribution is not acceptable for use with a SLT
				system. The dose pump or siphon must" be capable of delivering a controlled
				dose of septic tank effluent at an application rate of from 0.25 to 0.5 gallons
				per linear foot of trench.
The filtration section of a SLT is illustrated in the
				accompanying drawing. Basically, it consists of a conventional gravel bed or
				gravel-less pipe surrounded by at least 12 inches of filter sand in all
				directions except the top. The gravel bed or gravel-less pipe should be covered
				with 2-4 inches of sand. The entire SLT is then covered with untreated building
				paper or soil fabric before the earth cover is added. At this time, the gravel
				bed design and the gravel-less design are considered equal. When using the
				gravel-less pipe, the drainfield connections and inspection ports designed for
				use with gravel-less pipe systems are required.
The size of the SLT is determined by the number of bedrooms in
				the residence. Each bedroom will require 95 feet of trench. Commercial
				establishments (domestic waste only) may be sized by using 0.75 linear feet of
				trench per gallon of septic tank effluent.
All SLT trenches must be installed on contour. An inspection
				port suitable for monitoring the water level must be provided for each trench
				in a SLT system.
SIZING A SAND-LINED TRENCH
				SYSTEM
Residential
Non-Commercial
Number of Bedrooms
Linear Feet of Sand-Lined Trench
Multiply the Estimated Sewerage Flow (gallons/day) by
						  0.75
1
95
2
190
3
285
4
380
A list of sources for approved sand is provided in Attachment
				1.
2 Sand-lined Trench Details -Either is acceptable -Both
				must be dosed -Use 95 linear feet/bedroom
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UNDERDRAIN SYSTEMS
Underdrains may be used in relatively level areas to lower the
				seasonal water table in order to use standard absorption trenches or capping
				fill systems. Underdrain systems are intended to be used on soils that meet the
				hydraulic conductivity requirements for standard systems. The minimum
				separation of absorption trenches Is 10 feet on underdrain systems. The
				underdrains are similar to curtain drains and are situated between the
				absorption trenches (see drawing).
The underdrains are from 6-12 inches wide and up to six feet
				deep. A four inch perforated PVC Pipe is placed in the bottom of each
				underdrain and covered with at least 12 inches of sand. The underdrains are
				backfilled with the original material. The ends of the PVC pipe are connected
				to the sump or discharge line.
The discharge from an underdrain systems is considered treated
				sewage and must be retained on-site or meet NPOES requirements for an off-site
				discharge. Road or highway ditches are not an acceptable route of
				discharge.
Underdrain System
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WISCONSIN SAND MOUND SYSTEMS
Sand mounds are an alternate method of on-site sewage disposal
				pioneered by the University of Wisconsin. The state of Wisconsin has adopted
				this system as a standard means of soil absorption. Since the soils encountered
				in Arkansas are markedly different from those in Wisconsin, sand mounds are
				considered an experimental system. Since the requirements established by
				Wisconsin are as up to date as any available, all sand mound submissions must
				comply with the current site, design and construction requirements established
				by the Wisconsin Department of Industry, Labor and Human Relations. Information
				may be obtained through the Department's main offices in Madison.
The purpose of the sand mound is to renovate the septic tank
				effluent by passing it through an adequate sand fill (see Attachment 1) and
				introducing this renovated wastewater into the natural soil
over
a broad area. They may be used to overcome such soil/site limitations
				as permeable soils at sites with a high seasonal groundwater table, rapidly
				permeable soils over cracked or creviced bedrock, and slowly permeable soils at
				sites with or without a seasonal groundwater table near the surface. The
				minimum depth of a soil over cracked or creviced bedrock is two feet. The
				maximum elevation of seasonal groundwater at the proposed site is two feet from
				the natural soil surface. No sand mound installation will be approved in a
				flood plain or a filled site. They will not be approved for installation on top
				of a failed conventional system.
Wisconsin sand mounds have been evaluated for several years In
				Arkansas. The life expectancy of a properly constructed and maintained mound
				appears to be 7-10 years. Therefore, when mounds are utilized, a site for a
				second mound or alternative must be included in the proposal.
Most of the problems encountered with existing mounds were a
				result of:
1. The use of inappropriate
			 fill material. Current specifications call for a clean sand from the list of
			 approved sources in the appendix section of this document. Previous use of
			 ungraded sand, concrete sand, and "river sand" have proven unsatisfactory. The
			 source and a sample of the sand to be used should accompany the plan
			 submittal.
2. Construction errors
			 have resulted in many sand mound failures. The most common construction error
			 is in the assembly of the pressure distribution manifold. The pressure
			 generated by the dose pump are generally greater than those normally
			 encountered with residential water systems. The proper preparation, priming and
			 gluing of the PVC pipe joints, is critical. Other construction errors observed
			 include inadequate site preparation, the use of rubber tired vehicles in
			 constructing the mound, too steep of a side slope, corrosion of electrical
			 connectors made inside the dose chamber, and inadequate measures to prevent
			 erosion of the newly constructed mound. Most of these errors were not
			 intentional, but resulted from the installers lack of familiarity with this
			 type of system.
3. The original
			 Wisconsin design called for a single large dose of effluent to the sand mound.
			 This resulted in overloading the gravel bed and a change to 3 to 4 doses per
			 day was made.
4. The placement of a
			 mound on an unsuitable site has caused several failures. Areas that are too
			 steep (over 8% slope), have rock-out crops or demonstrate an irregular terrain
			 and should be avoided.
Due to the complex design and construction requirements of this
				type of system, the Designing Engineer or Designated Representative will be
				responsible for overseeing the construction.
Typical Sand Mounds
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SURFACE DISCHARGING SYSTEMS
As of April 1, 1991, all off-site sewage discharges from
				individual homes are subject to National Pollutant Discharge Elimination System
				(NPDES) Permit requirements. Individual homes with discharges remaining on the
				owner's property are not subject to these requirements. All commercial
				operations are subject to NPDES permit requirements.
To insure on-site retention of sewage effluent, a minimum lot
				size of three acres is required on all proposals Involving a surface discharge
				system. When a surface discharge system Is proposed to replace an existing
				failed sewage disposal system, the three acre minimum lot size may be waived.
				This does no£ relieve the owner from meeting NPDES requirements.
When a surface discharge system fails to function properly or
				does not consistently meet the discharge requirements, the discharge of sewage
				must stop Immediately. The owner will be allowed to use the septic tank, or
				mechanical treatment plant as a holding facility until adequate repairs are
				made. The sewage from these holding facilities must be pumped by a licensed
				septic tank cleaner and disposed of at an NPDES permitted f ac i 1 i ty.
The current maximum pollutant levels are listed below. Some
				streams and drainages may have more stringent limits.
Effluent
						  Characteristics
Effluent 30 Day Average
Limitations Daily
						  Maximum
Monitoring Measurement
						  Freauency
Requirement Sample Type
Flow (must be monitored & reported)
Monitor
1,000gpd
2/year
estimate
5 Day Biochemical Oxygen Demand (BOD)
20 mg/1
30 mg/1
2/year
grab
Total Suspended Solids
20 mg/1
30 mg/1
2/year
grab
Fecal Coliform (colonies)
200/100ml
400/100ml
2/year
grab
pH
6.0 - 9.0
6.0 - 9.0
2/year
grab
All off-site discharges must be adequately disinfected prior to
				discharge. The requirements for disinfection are discussed at the end of this
				section.
It is the responsibility of the homeowner to adequately
				maintain the sewage treatment system and to insure that the effluent limits are
				met. The homeowner is also responsible for all costs relating to monitoring and
				record keeping. An approval by the Health Department is no guarantee that the
				design is capable of meeting the established limits. Sewage discharges into
				lakes used as a primary or secondary water supply or bodies of water used for
				body contact sports are not acceptable and will not be permi tted.
Alternative/experimental systems are not intended and will not
				be approved as a uniform plan of development in any subdivision, residential
				area, or any developed or high use areas. Only sites demonstrating sufficient
				isolation from the populous will be considered. Any reduction in the approved
				lot size or any increase in the sewage load will void Health Department
				approval.
AEROBIC TREATMENT PLANTS
Commercially available aerobic package treatment plants
				designed for individual family dwellings are frequently used in place of site
				built treatment facilities. These provide a commercially designed and tested
				device along with a performance warranty and maintenance service. Being
				premanufactured, they can be installed in a relatively short time and weather
				delays are not common. A list of approved treatment plants is provided In
				Attachment 4 and the requirements for becoming approved are discussed in
				Appendix I of this manual.
Aerobic treatment plants are required to meet the same
				permitting and discharge requirements as other treatment schemes. Being a
				mechanical device, regular, routine, maintenance is absolutely necessary for
				continued performance. Owners of aerobic treatment plants must maintain a valid
				service contract with a certified individual or company. Licensed aerobic
				treatment plant distributors and sewage treatment plant operators certified
				through training provided by either the Arkansas Department of Pollution
				Control and Ecology or the Arkansas Environmental Academy meet this
				requirement. Licensed distributors must provide factory certified maintenance
				personnel and service. It is the responsibility of the homeowner to pay for all
				maintenance, effluent testing and records keeping.
Health Department surveys have noted a high malfunction rate
				for aerobic treatment plants. A lack of routine maintenance appears to be the
				major problem. It is very important for the homeowner to understand the
				maintenance requirements and the costs relating to those requirements before
				selecting an aerobic treatment plant.
INTERMITTENT SAND FILTER
Intermittent sand filters used with properly sized and
				maintained septic tanks or aerobic treatment plants are capable of producing a
				high quality effluent to meet state discharge requirements. Disinfection is
				required on all surface discharge systems. The disinfection requirements are
				stated in another section of this manual.
Following pretreatment (e.g. septic tank.) the effluent is
				pumped through a distribution grid ponding the surface of the filter sand. The
				pretreated effluent 1s renovated as it percolates through the filter sand. The
				effluent is collected by 4 inch perforated PVC pipes located An a gravel bed
				under the sand filter. The effluent is then routed to the disinfection
				apparatus just prior to discharge.
The successful use of sand as a filter media is dependent on
				the chosen size and uniformity of the grains. Filter media size and uniformity
				are expressed in terms of "effective size" and "uniformity coefficient". The
				effective size of the sand media affects the quantity of sewage that may be
				filtered, the filtration rate, the depth particles penetrate, and the quality
				of the effluent. A sand media that is too coarse reduces the retention time to
				the point that adequate renovation is not attained.
Uniform application to the sand media is addressed by pumping
				the pretreated sewage through a pipe manifold system. This uniformly loads the
				filter with a relatively low volume of sewage that can be repeated several
				times during the day. This regime allows for maximum filter retention time and
				the use of small effluent pumps while optimizing treatment. The distribution
				apparatus normally consists of a 1½ to 2 inch schedule 40 PVC manifold
				with 1¼ inch laterals with 3/16 inch holes drilled every 30 inches. The
				laterals are spaced from 30 to 36 inches apart. All joints and connections must
				be properly glued.
The filter bed is covered with 6 to 18 inches of earth to
				eliminate the nuisance odors associated with septic effluent. Based on normal
				operating conditions, life expectancy of these systems is seven to ten years.
				Costs to provide the required maintenance for the filter bed are extremely high
				due to the necessity of removing and replacing the earth cover. This factor
				should be considered by the designer when selecting a treatment scheme since
				the homeowner will be financially responsible for operation and
				maintenance.
Dosing tanks equipped with a properly sized sewage effluent
				pump are essential for all sand filter beds. This will permit the proper
				distribution for the effluent over the entire sand filter area. Recommended
				dosage volumes and pump or siphon sizes can be determined from the design
				criteria presented in the tables provided below.
ISF's situated on sites where ground water contamination is
				possible will be required to use a 30 mil, or thicker, liner. A list of
				approved liners provided in Attachment 3.
DESIGN CRITERIA FOR INTERMITTENT SAND
				FILTERS
Waste Water
150 gallons/day/bedroom
Volume Loading Rate
1.25 gallons/square foot/day
Dose Volume
From 20 to 25 percent of estimated
						  gallons/day
Application Rate
10 gallons/minute/bedroom - minimum
Maximum Bed Length
50 feet
Distribution Manifold Distribution
						  Laterals
1.50 inches diameter, 3/16- inch-holes on 30 inch
						  centers, laterals 30 to 36 inch center to center
filter-Sand
See Appendix IV
Septic Tank With Earth Covered Intermittent Sand Filter
				Bed
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LAGOON SYSTEMS
Small, shallow sewage lagoons serving an individual residence
				will be considered on sites demonstrating a sufficient isolation. Like other
				surface discharge systems, lagoons are not for use in subdivisions or other
				densely populated areas. Lagoons must be located at least 100 feet from the
				owners house and at least 300 feet from any other residence or other high-use
				area. Sewage lagoons should not be situated where they would block a drainage
				area and create ponding in the surrounding area. Lagoons should be located at
				least 100 feet from property lines or other areas readily accessible to the
				public. All trees located within 100 feet of the lagoon must be removed and not
				allowed to re-establish. Sunlight and wind are vital for proper lagoon
				operation.
All treatment schemes utilizing lagoons must provide adequate
				pretreatment with either a conventional septic tank or an approved aerobic
				treatment unit. Filtration and chlorinatlon are required on lagoons with an
				off-site discharge. Lagoon effluent discharged off-site must meet all NPDES
				requirements.
The following chart indicates the side length of lagoons
				required for various sized residences. For residences with more than four
				bedrooms, the formula below on the chart may be used to calculate the side
				length. Note that lagoons are not recommended for residences with less than 2
				bedrooms or with an estimated daily flow less than 300 gal Ions per day.
Lagoon Sizing Chart
Number of Bedrooms
Estimated Gallons/Dav
Side Length 3' Working Depth
(Square Lagoon)4' Working Depth
1
150
Not Recommended
2
300
35'
30'
3
450
42'
37'
4
600
49'
42'
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In general, the construction requirements for an individual
				sewage lagoon are similar to the Soil Conservation Service construction
				guidelines for stock ponds or tanks. The berm or levee should have a 2:1 or a
				3:1 slope depending on the soil properties at the site. The berm should also
				have a relatively flat surface at the top approximately one foot wide. The
				height of the berm is determined by the difference in elevation between the
				natural ground surface and the bottom of the lagoon. The bottom of the lagoon
				should be above the wet seasons' groundwater level. This will prevent seasonal
				groundwater from occupying the working depth and thus overloading the system.
				The designed working depth on an individual home lagoon should be about three
				feet with a maximum (or overload) depth not to exceed five feet. On a typical
				installation, the bottom of the lagoon would be about two feet below the
				natural ground surface. This may vary allowing for different soil properties
				and lagoon size limitations.
Lagoon Profile
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After construction, the berm should be sodded or seeded with a
				suitable grass cover, and a fence must be constructed around the lagoon to
				prevent entry by children or pets. A gate providing access for maintenance and
				sampling is required.
At least two feet of water should be added to the lagoon before
				the Initial use. This will establish aerobic conditions in the lagoon which
				will aid in proper operation. A properly operating Lagoon will be green in
				color and present no odor. Hhen a lagoon goes septic, the water will turn dark
				and begin to stink. If the water level in the lagoon is below two feet, make-up
				water should be added to dilute the effluent and to reinstate an aerobic
				environment. If, after the addition of make-up water, the lagoon is still
				septic, add lime on a daily basis until the lagoon again becomes green and
				ceases to cause odors.
A sewage lagoon is not a maintenance free system. The area
				around the lagoon should be kept mowed and no trees or shrubs should be allowed
				to establish on the berm. Woody plants tend to block wind and sunlight and
				their roots cause leaks in the lagoon berm.
DESIGN FOR CRITERIA FOR ROCK PLANT
				FILTERS
The Rock Plant Filter (RPF) is a method of providing secondary
				treatment to septic tank effluent. A RPF is essentially an artificial marsh
				that relies on the action of microorganisms on the rock media, absorption by
				the roots of aquatic plants and microbes working together to achieve treatment.
				The top surface of the filter must be open to the air, but odor problems are
				not anticipated. A RPF system may be considered on sites where low soil
				permeability prohibits the use of a conventional residential septic system.
				Sites demonstrating a slope greater than 8% will not be considered. The
				characteristics and shape of the proposed RPF site will determine which of the
				two bed designs is most applicable. No variations from the bed designs shown
				below will be considered. A typical cross section has been included to better
				explain the design concept. Discharge from a RPF must be retained on this
				owner's property. This requires at least a 3 acre lot. This requirement may be
				waived on repairs to existing, failed septic systems. All off-site discharges
				must be chlorinated prior to discharge. All off-site discharges require an
				NPDES Permit from the Department of Pollution Control and Ecology.
Primary treatment for the RPF system is accomplished with a
				conventional septic tank. Residences with 1 or 2 bedrooms will require a 1,000
				gallon tank (minimum) and residences with 3 or 4 bedrooms will require a 1,250
				gallon tank. The septic tanks used must comply with all requirements outlined
				in Health Department regulations. When replacing an existing, failed septic
				system, the existing concrete septic tank may be used if it is in good repair,
				adequately baffled and meets the standard sizing criteria for subsurface
				absorption field systems. If the RPF is installed at an elevation higher than
				the outlet of the septic tank, an approved dose chamber and pump will be
				required.
The RPF itself is essentially a shallow, completely level,
				rectangular gravel bed with septic tank effluent ponded at a designed depth of
				one foot and with a total gravel depth of 18 inches. The gravel used must be
				clean, washed creek gravel and may range in size from 1/2 inch to 1 1/2 inches.
				Do not use crushed stone. Also, do not use pea gravel on the surface or any
				other part of the RPF. The RPF beds are to be installed on contour and level.
				The plants from the accompanying list are planted at regular intervals with the
				roots below the level of the ponded effluent. As suitable plants are
				determined, they will be added to the list. All soil must be washed from the
				plants' roots prior to planting in the RPF. All installations will require a
				plastic bed liner. A single layer, 30 mil plastic liner with inlet and outlet
				boots, is required. A list of suppliers for approved liner materials is
				provided in Attachment 3. Multiple layers of a liner material less than 30 mils
				is not acceptable. Roots projecting into the RPF trench must be trimmed even
				with the trench wall or bottom to prevent damage to the liner. The RPF must be
				constructed to prevent any surface water or groundwater from entering the
				filter bed. This would wash soil into the filter, thereby clogging the bed.
				This would also reduce the residence time of the sewage in the RPF.
The inlet and outlet devices for a RPF must be designed to
				insure even distribution and collection and to reduce the possibility of
				clogging. Both the inlet and outlet devices are to be installed at the same
				level to pond the septic tank effluent at a one foot depth. The inlet and
				outlet devices consist of a 10 foot, 4 inch perforated PVC Pipe with a standard
				"T" fitting in the center. These are installed within one foot of the ends of
				the bed. The ends of all pipes must be capped.
All RPF beds must have a border to exclude surface runoff and
				prevent loose soil from being washed into the filter bed. This border must
				extend at least 4 inches above the surface of the soil around the bed and
				extend at least 4 inches below the surface of the soil around the bed and
				extend at least 4 inches below the soil surface. The border may be constructed
				of either treated landscaping timbers nailed together or of treated lumber. Any
				other border material must be approved by the agency prior to use.
Before planting the plants, the filter must be ponded to the
				designed working depth to provide water for the roots. The filter may be ponded
				slightly deeper after planting to insure that water is available for the new
				plants. This is easily done by capping the outfall pipe. The minimum number of
				plants required is on the accompanying chart. The plants are to be planted on
				staggered, 18 inch intervals. All soil is to be removed from the root ball just
				prior to planting. It may be desirable to apply a water soluble fertilizer
				after planting to start plant growth. It may be necessary to either flood the
				bed or add water with a "soaker hose" for a period of time after the plants are
				installed. Aquatic plants need plenty of water to survive and grow. Yearly
				maintenance is accomplished by removing the dead plant material (not the roots)
				each spring and preventing grass or weeds from being established in the
				RPF.
Management practices to enhance on-retention of the sewage
				effluent are encouraged.
AQUATIC PLANTS CONSIDERED FOR USE IN ROCK PLANT FILTERS
Scientific Name
Arrow Arums
Peltrandra virginica
Arrowhead
Sagittarida latifolia
Cattail
Typha latifolia & T. angustifolia
Giant Reed
Phragmites australis & P. communic
Pickrelweed
Pontederia cordata
Canna Lily
Canna flaccida
Call a Lily
Zantedeschia aethiopica
Bull Rush
Scripus americannus
Elephant Ear
Calocafia esculentia
Ginger Lily
Hedychium coronatum
Sweet Flag (Calamus)
Acorus calamust & A. americanus
Spatterdock
Nuphar luteum
Lobelia
Lobelia siphilitics & L. cardinalis
Soft Rush
Juncus effusus
Water Plantain
Alisma plantago aquatica
Blue Water Iris
Iris versicolor
Yellow Water Iris
Iris pseudacorus
Sizing Criteria
Number of Bedrooms
Estimated Flow (150 gpd/bedroom)
FiIter Size (ponded)
Dimensions
Minimum Number of Plants
2 (Min)
300
210 Ft.
10.25'x20.5'xl.5'
50
3
450
269 Ft.
11.4'X22.B'xl.5'
63
4
600
310 Ft.
12.4'x24.8'xl.5'
75
*For additional bedrooms, add 50 ft. to filter size and 12
				plants.
Rock/Plant Filter
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				here to view image
DISINFECTION OF SEWAGE EFFLUENT
All effluent from individual home treatment systems must be
				adequately disinfected prior to the point of surface discharge. Any proven
				conventional disinfection method will be given due consideration. Approved
				disinfection methods Include:
1.
			 Positive contact, dry feed chlorinators
2. Hypochlorlnators
3. Ozone units
4. Ultraviolet light units
Tablet feed, erosion chlorinators are the most widely used.
				Only commercially available chlorinators will be considered. Design and/or
				performance data must be included in the plans submitted. Chlorinators proposed
				for installation must be capable of automatic operation and must provide a
				controlled chlorine dosage proportional to the effluent flow rate. A minimum
				dosage of 10 ppm chlorine and a contact time of at least 30 minutes during peak
				flow periods is required. When tube feed, tablet type chlorinators are
				proposed, they shall be designed to deliver a continuous, unhindered gravity
				feed of the tablets. Some tablet types have a tendency to wick, and swell in
				the tubes. This results in a stoppage of the chlorine tablet feed.
A chlorine contact chamber must be provided following the
				chlorinator to insure adequate disinfection of the effluent. The chamber must
				be well baffled to prevent any direct path for flow between chamber inlet and
				outlet. The minimum acceptable size is 25 gallons for most residences. The
				sizing of the contact chamber for other types of establishments will be done on
				an individual basis. The point of discharge from the chamber must be well above
				the high water level of the receiving stream or ditch. The chamber discharge
				elevation must also be below its influent elevation to prevent filter
				flooding.
Proposals for ozone and ultraviolet light devices must be
				accompanied by installation, operation and performance data supplied by the
				manufacturer. This should include laboratory tests results demonstrating the
				capabilities of the units.
OTHER WASTEWATER DEVICES
The devices disussed In this section are neither soil
				absorption nor treatment systems. They are special use system designed for low
				use applications or to reduce the amount of sewage going into another type of
				system.
HOLDING TANKS
Holding tanks are only economically feasible on buildings with
				small daily flows. Examples are office buildings or small stores (not grocery
				or food service) with employee toilets and lavatories only. Holding tanks will
				not be considered for residences (full or part time) due to the quantity of
				wastes generated. Since all wastes will be stored on-site until pumping, a
				1,000 gallon or ten day capacity whichever is larger, will be the minimum size
				allowed. Holding tank systems must be readily accessible for pumping in all
				seasons and weather conditions. A gravel or paved surface for the pumping truck
				must be adjacent to the tank. The pumper truck must be able to drive to within
				10 feet of the service riser. To facilitate pumping, a 12 inch diameter riser
				will be required on all holding tanks.
Proof of a notarized contract with a licensed septic tank
				pumper will be required before a permit to operate is issued. The contract must
				provide for pumping within 24 hours of notification and state where the sewage
				will be deposited. Unlike septage, holding tank contents
cannot
be land applied. The only acceptable method of
				disposal is deposition into a municipal sewage treatment plant with which the
				septic tank pumper has permission to dump. In some areas of the state, it is
				difficult to find a treatment plant willing to accept holding tank wastes. This
				should be explored before proposing this type of system. The owner of the
				structure being served by a holding tank is ultimately responsible for the
				proper disposal of the holding tank contents.
All holding tanks must be watertight. A Schedule 40 sanitary
				tee must be provided for the inlet. An alarm float must be installed in the
				holding tank to indicate when 757, of the capacity has been reached.
				Information on the float alarm system's brand name, manufacturer, use and
				installation must be provided at the time plans are submitted. The alarm
				itself, either audible, visual, or both, must be installed inside the structure
				being served and in a visible location. The name of the licensed pumper and his
				telephone number must be displayed on the alarm.
Since all waste from a holding tank system are pumped, water
				saving devices are strongly recommended. These can substantially reduce the
				daily volume of effluent produced and therefore will reduce the frequency and
				cost of pumping.
The use of holding tanks for establishments with a small daily
				waste flow have generally been successful. Some of the problems encountered
				have been the lack of a suitable disposal site, groundwater infiltration that
				greatly increased pumping frequency, alarm failure, failure of employees to
				respond to the alarm and the inability to pump the holding tank in very
				inclement weather. The owner of the building to be served should be aware of
				these potential problems.
Typical Holding Tank
Click
				here to view image
COMPOSTING AND INCINERATING
				TOILETS
A composting toilet is a device specifically designed to retain
				and process body wastes and, in some cases, household garbage by biological
				degradation. The process may be either thermophilic or mesophj.lic depending on
				the design of the toilet. Thermophilic devices are normally smaller and require
				some type of energy input to maintain the desired temperature. Mesophilic
				devices rely on the heat produced by the biological process to maintain the
				required temperature. Whether or not a device can accept household garbage is
				dependent on it's design and intended use. An incinerating toilet is a device
				designed to reduce body wastes, both urine and feces, to an ash residue.
				Needless to say, a significant input of energy is required. The type of energy
				used is dependent on the design of the device used.
Only manufactured composting and incinerating toilets which
				have been tested and approved. Each application requesting approval of a
				composting or incinerating toilet must also provide for the disposal of the
				homes1 greywater. Household greywater wastes,
				exclusive or urine and feces, must be handled and disposed of in a manner
				approved by the Arkansas Department of Health. The preferred method of handling
				greywater is through a conventional septic tank and absorption field. Since the
				use of a composting or incinerating device will reduce to volume of household
				wastes, a 35% reduction in the absorption field size will be granted. Other
				methods of treating and/or disposing of greywater will be reviewed on a case by
				case basis. Only those methods which adequately protect the health of the
				homeowner and the public will be considered. All methods utilizing a discharge
				of any type must be capable of producing an effluent meeting current discharge
				standards. When the discharge cannot be expected to be retained on-site,
				easements from affected property owners will be required.
Some manufacturers claim the stabilized compost is safe and may
				be used as a soil additive in gardens. The actual health risks associated with
				this composted material have not been adequately assessed. The stabilized
				compost from a composting toilet must be buried onsite or deposited in an
				approved sanitary landfill. The ash from incinerating toilets requires no
				special handling since any pathogen would be destroyed in the incineration
				process.
A list of approved composting and incinerating devices is
				provided in Attachment 2. All composting and incinerating devices must be
				evaluated by an ANSI approved laboratory under NSF standard 41.
APPENDIX I
Requirements for the Approval of Aerobic Treatment
				Plants For Distribution In Arkansas
Aerobic treatment units may be used for treating domestic
				sewage waste, provided that each unit is installed, operated and maintained in
				conformance with the following provi sions:
1. Aerobic systems designed to treat up to
			 1,500 gallons of sewage waste per day shall be listed by a third party
			 certifying program approved by the Arkansas Department of Health. Aerobic
			 treatments units shall be in compliance with standards for Class I systems as
			 defined by ANSI/NSF International Standard Number 40, revised July 1990. An
			 approved third party certifying program shall comply with the following
			 provisions in order for units which it has certified to be approved for use in
			 Arkansas:
(a) Be accredited by the American
			 National Standards Institute.
(b)
			 Have established procedures which send representatives to distributors in
			 Arkansas on a recurring basis to conduct evaluations to assure that
			 distributors of certified aerobic units are providing proper maintenance, have
			 sufficient replacement parts available, and are maintaining service
			 records.
(c) Notify the Arkansas
			 Department of Health of the results of monitoring visits to manufacturers and
			 distributors within 60 days of the conclusion of the monitoring. Approved
			 distributors must be reported by the manufacturer to the certifying
			 agency.
(d) Submit completion
			 reports on testing for review by the Arkansas Department of Health.
(e) Provide a registered certification mark
			 or seal which must be affixed in a conspicuous location on the units it has
			 certified. This mark or seal will alert persons evaluating or maintaining the
			 unit that the unit is in compliance with ANSI/NSF Standard 40.