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Environment Bay of Plenty On-Site Effluent Treatment Schedule 1 Regional Plan 2006

89

Schedule 1 — System Design Requirements for New Conventional On-Site Effluent Treatment Systems to Meet Minimum Requirements for Permitted Activities

This schedule specifies various design options for on-site effluent treatment systems which meet the minimum requirements for permitted activities.

For new subdivisions, the overall lot (section) size must take into account the area required for the house, garage, drive, hard surface areas (paths, out buildings), garden areas, plus the treatment area, required to accommodate the initial soakage field system plus reserve area and incorporate buffer clearances and setbacks required by the district plan. For existing subdivided development, the selection and design of the pre-treatment and soakage field system may be constrained by the available space on the lot (section) in which to locate the treatment area.

In accordance with Rule 3 of the plan, new systems to be installed after the On-Site Effluent Treatment Regional Plan 2006 becomes operative are permitted activities only if, among other requirements stated in the rule, the system meets certain minimum design standards as specified in the following tables.

Advisory Notes:

1 The conventional on-site wastewater pre-treatment unit must be sized according to the formulae provided in Table 5.

2 Conventional on-site effluent treatment systems with a total score between 1 and 4 (inclusive) from Table 6 are permitted activities, provided that the minimum requirements for trench length set out in Table 7 are met (including the reserve area requirement that shall be kept free from inappropriate development (buildings and impervious surfaces).

3 Conventional on-site effluent treatment systems with a total score of 5 or more from Table 6 are discretionary activities, unless the systems can be modified in accordance with the modification factors set out in Table 8 and thereby meet the minimum requirements for permitted activities.

4 Where permeability testing is to be undertaken to assist in confirmation of soil category for design purposes, then such testing shall be carried out in accordance with AS/NZ 1547:2000, “Soil Permeability Measurement – Constant-head Test”.

Schedule 1 On-Site Effluent Treatment Environment Bay of Plenty Regional Plan 2006

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Table 5 – Septic Tank Capacities

A: Number of Bedrooms Minimum Tank Capacity/Size (Litres) 1 to 3 2700 4 to 6 3300 Notes: 1. Effluent outlet filter installation is the preferred septic tank design approach for all conventional on-site effluent treatment systems 2. As volume measured from outlet invert to septic tank base (i.e. liquid volume), if a garbage grinder is installed in a conventional effluent system, an effluent outlet filter should be installed at the outlet of the septic tank to protect the soakage field, and the tank size should be increased to the larger size to accommodate the extra solids produced.

B: Households (Blocks of Units/Flats) (Refer to Table 9) For 10 persons or more the capacity (C) may be determined by the formula C = (P x A) + 2000 litres where P = the number of persons to be served and A = the daily wastewater flow allowance in litres/person/day

C: Institutions (Refer to Table 9) For flows greater than 700 litres per day the capacity (C) may be determined by the formulae

as set out below: Motels/Hotels - without restaurant C = (P x A) + 2000 litres - with restaurant C = (P x A) + 3000 litres Community halls, schools, rural C = (P x A) + 2000 litres factories, shopping centres, camping grounds where P = the number of persons to be served and A = the daily wastewater flow allowance in litres per person per day


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Table 6 – Factors Restricting Choice of Conventional On-Site Effluent Treatment System

Select one item from each of numbered sections below and put the score in “1st score” column to find out first score.

On-site effluent treatment systems with a total score between 1 and 4 (inclusive) from Table 6 are permitted activities provided they meet the requirements of Rule 3 of the Plan. On-site effluent treatment systems with a score of 5 or more from Table 6 are discretionary activities unless the systems can be modified in accordance with the modification factors set out in Table 8.

Factor 1st Score

2nd Score (if

necessary) 1 Pre-Treatment Level

(Maintenance access should be provided) (a) Single stage septic tank with approved

effluent outlet filter (b) Two stage septic tank and approved

effluent outlet filter (c) Greywater only

2 2 1

2 Depth to Highest Groundwater Table

Conventional On-Site Effluent Systems below bottom of soakage field land treatment area4

greater than 1500 millimetres between 1200-1500 millimetres between 600-1200 millimetres between 0-600 millimetres

0 1 2 4

3 Soil Category (Refer to Table 10)

1 gravel, coarse sand; rapid draining; 2 coarse to medium sand; free draining; 3 medium-fine and loamy sand; good

drainage; 4 sandy loam, loam and silt loam; moderate

drainage; 5 sandy clay-loam, clay-loam and silty clay-

loam; moderate to slow drainage. 6 sandy clay, non-swelling clay and silty

clay; slow drainage. 7 swelling clay, grey clay, hardpan; poorly

or non-draining.

2 1 1 0 0

4 4

4 See ‘Definition of Terms’ for definition of ‘Treatment Area’


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5 A restrictive soil horizon may be a change in soil textural class or some other change which severely reduces drainage.

4 Restrictive Soil Horizon5 (barrier to soil soakage)

Restrictive drainage soil horizon within 2 metres of soil surface. Restrictive drainage soil horizon deeper than 2 metres of soil surface.

4

0

5 Slope less than 15 percent slope (8.5o) greater than 15% (8.5o)

0 3

6 Barrier to Horizontal Soil Soakage Within 3 metres

(For example vertical cuttings, retaining walls, building walls etc. in the soil profile)

greater than 3 metres and greater than 45

degrees from the toe of a wall/embankment less than 3 metres or less than 45 degrees from the toe of the wall/embankment

0

4

7 Proximity to Surface Water (including ephemeral) or Water Supply Bore

(i) Greater than or equal to 40 metres (ii) Between 20-40 metres (iii) Less than 20 metres

0 1 4

TOTAL SCORE


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Table 7 – Effluent Treatment Trench Length Required (in metres) for Discharge Volumes of up to 2 cubic metres per day to Standard Trenches

Soil Category

1 (LPED)1 2 3 4 5

Ave

rage

dai

ly

flow

(L)2

Num

ber

of

Bed

room

s

Min

. Tre

nch

Leng

th (m

etre

s)

Req

.

Are

a R

eq.

(met

res2 ) i

ncl.

Res

erve

Are

a

Min

. Tre

nch

Leng

th (m

etre

s)

Req

. A

rea

Req

. (m

etre

s2 ) inc

l. R

eser

ve A

rea

Min

. Tre

nch

Leng

th (m

etre

s)

Req

. A

rea

Req

. (m

etre

s2 ) inc

l. R

eser

ve A

rea

Min

. Tre

nch

Leng

th (m

etre

s)

Req

. A

rea

Req

. (m

etre

s2 ) inc

l. R

eser

ve A

rea

Min

. Tre

nch

Leng

th (m

etre

s)

Req

. A

rea

Req

. (m

etre

s2 ) inc

l. R

eser

ve A

rea

Up to 500 16 64 22 90 37 150 45 180 75 300

Up to 1000 1 to 3 32 128 45 180 74 300 90 360 150 600

1000-1400 4 45 180 60 240 105 420 125 500 210 840

1400-1600 5 50 200 70 280 120 480 145 580 240 960

1600-2000 6 64 256 90 360 148 590 180 720 300 1200

More than 2000

7 or more Resource consent is required for discharges >2m3/day

Advisory Notes: 1 For Category 1 soils a low pressure effluent distribution system (LPED) must be used. This

system utilises pump dosed loading into a perforated small diameter pipe inserted within draincoil (refer Figure 4). The LPED dosing system requires careful design to ensure even distribution throughout the full trench system. Automatic sequencing valves may be used in preference to pressure manifolds. Pressure dosing systems must incorporate an alarm/warning system on the pump unit to detect failure of the system at an early stage.

Soil Category 1 = gravel, coarse sand; rapid draining;

Soil Category 2 = coarse to medium sand; free draining;

Soil Category 3 = medium-fine and loamy sand; good drainage;

Soil Category 4 = sandy loam, loam and silt loam; moderate drainage;

Soil Category 5 = sandy clay-loam, clay-loam and silty clay-loam; moderate to slow drainage.

2 The values in the “average daily flow” column are to be used in the design sizing of trench systems for domestic wastewater producing facilities serving staff/employees in office, commercial, retail and light industrial premises. Where flows are below 1,000 litres/day, then trench lengths may be “pro rata” reduced down to, but to not less than 50% of those for 1,000 litres/day.


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Table 7 is based on the following:

• 0.45 metre wide gravel filled standard trench (Figure 4 trench configuration). The width of the trench may be reduced as long as the trench length from Table 7 is increased by the following formula:

Narrow Trench Length = (T x 0.45)÷W where T = trench length from Table 7 W = trench width. The trench width must not exceed 0.45 metres. D = spacing between adjacent trenches (sidewall to sidewall). The minimum is 1 metre although 2 metres is preferable (see diagram below).

• 100% reserve area so that if the soakage field fails, there is room to develop another field.

• For discretionary activities these lengths may exceed those recommended in Table 7.

• Any compaction of a soakage field is to be avoided.

1 metre

Ground surface


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Figure 5 – Low-Pressure-Effluent-Distribution (LPED) for Standard Trenches


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Table 8 – Modification Factors for Conventional On-Site Effluent Treatment Systems

The following improvements may be used to modify the treatment or site conditions if the total score from Table 6 exceeds 4.

Limiting Factors Requirement Solution or Recommendation for

Type of Specific Advice

Go Back to Table 6

1 Pre-treatment Level

Improve the pre-treatment level

Select improved system from Table 6

2 Groundwater Too High

Raise soakage field to allow 600 millimetres clearance for conventional systems

or improve the pre-treatment level

- Raise soakage field to level with ground

- mound systems

- advanced treatment system and irrigation lines.

Go to Rule 12 or 13

3 Restrictive Soil Horizon

- remove restriction

- increase depth to restriction

- decrease loading

- improve pre-treatment

- break up iron pan/clay pan

- move soakage field across or up (e.g. mound)


Go to Rule 12 or

13

4 Horizontal Barrier

Increase distance to barrier Move system

5 Proximity to Surface Water

Increase distance to surface water

- Improve pre-treatment level

Move system


Go to Rule 12 or 13


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Table 9 – Wastewater Flow Design Allowances

SOURCE Typical Wastewater Flow Allowance in Litres/Person/Day [Note 1]

On-site Roof Water Tank Supply

Reticulated Community or

Household Borewater Supply

Households with standard facilities (including automatic washing machine)

140 180

Households with standard water reduction fixtures [Note 2] 115 145 Households with full water reduction facilities [Note 3] 80 110 Households with full water reduction facilities plus reclaimed water recycle for water closet flushing [Note 4]

65 95

Households with extra wastewater producing facilities (e.g. garbage grinders; douches)

170 220

Households - blackwater only (standard facilities) 50 60

Households - greywater only (standard facilities) 90 120 Motels/Hotels - guests, resident staff - non-resident staff - reception rooms - bar trade (per customer) - restaurant (per diner)

140 30 20 20 20

180 40 30 25 30

Community Halls - banqueting - meetings

20 10

30 15

Marae [Note 5] - day only visitors - day plus overnight visitors

30 130

40 150

Restaurants (per diner) - dinner - lunch

20 15

30 25

Tea Rooms (per customer) - without restroom facilities - with restroom facilities

10 15

15 25

Schools (pupils plus staff) [Note 6] 30 40

Rural Factories, Shopping Centres (staff) 30 50 Public toilets (including hand wash) [Note 7] 8 10 Camping Grounds - fully serviced - recreation areas

100 50

130 65

Advisory Notes: 1 These flows are recommended minimums for design purposes (unless actual flows from past experience are

available).

2 Standard water reduction fixtures include dual flush 11/5.5 litre water closets, shower flow restrictors, aerator faucets (taps), water conserving automatic washing machines.

3 Full water reduction fixtures include the combined use of reduced flush 6/3 litre water closets, shower flow restrictors, aerator faucets, front-load washing machines and flow/pressure control inserts on all water use outlets.

4 As for Note 3, plus on-site greywater treatment and recycle to toilet cistern, or on-site/off-site treatment and recycle of reclaimed water for water closet flushing.

5 Assumes that lunches and lunch/dinners will be served, and that overnight visitors have access to showers.

6 Based upon experience in the Auckland area, these values for schools are conservative. Recorded flows appear to be around 15 litres/person/day on rainwater tank supply, and 20 litres/person/day on community or borewater supply.

7 These are aggregate values applied to total daily visitor numbers (male and female).

Reference Sources: Gunn I (1994) On Site Wastewater Disposal from Households and Institutions. ARC Environmental Technical Publication No. 58

(Second Edition); AS/NZS 1547:2000; On-Site NewZ 99/1 (January 1999).


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Table 10 – Appearance and Feeling of Various Soil Textural Classes

Appearance and Feeling Soil Textural

Class Dry Soil Moist Soil Sand Loose, single grains which feel gritty.

Squeezed in the hand, the soil mass falls apart when the pressure is released.

Squeezed in the hand it forms a cast which crumbles when lightly touched. Does not form a ribbon between thumb and forefinger.

Loamy Sand Loose, single grains, which feel gritty but enough fine particles to stain fingerprints in the palm of hand.

Squeezed in the hand. It forms a cast that crumble when touched and only bears very careful handling.

Sandy Loam Aggregates are easily crushed. Very faint, velvety feeling initially, but as rubbing is continued; the gritty feeling of sand soon dominates.

Forms a cast that bears careful handling without breaking. Doesn’t form a ribbon between thumb and forefinger.

Loam Aggregates are crushed under moderate pressure; clods can be quite firm. When pulverised, loam has a velvety feel that becomes gritty with continued rubbing.

Cast can be handled quite freely without breaking. Slight tendency to ribbon between thumb and forefinger. Rubbed surface is rough,

Silt Loam Aggregates are firm but may be crushed under moderate pressure. Clods are firm to hard. Smooth, flour-like feel dominates when soil is pulverised.

Cast can be freely handled without breaking. Slight tendency to ribbon between thumb and forefinger. Rubbed surface has a broken or rippled appearance.

Silty Clay Loam

Aggregates are very firm. Clods are hard to very hard.

Cast can be handled very firmly without breaking. Tendency to ribbon between thumb and forefinger with some flaking, greasy feeling, moderately sticky.

Silty Clay Squeezed with proper moisture content into a long ribbon; sticky feel.


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Schedule 2 – System Design Requirements for New Advanced On-Site Effluent Treatment Systems to Meet Minimum Requirements for Permitted Activities

This schedule specifies various design options for advanced on-site effluent treatment systems which meet the minimum requirements for permitted activities.

In accordance with Rules 12 and 13 of the plan, new systems to be installed after the Operative On-Site Effluent Treatment Regional Plan 2006 became operative are permitted activities only if, among other requirements stated in the rule, the system meets certain minimum design standards specified in the following table.

Advisory Notes:

1 Advanced on-site effluent treatment systems with a total score between 1 and 4 (inclusive) from Table 11 are permitted activities.

2 Advanced on-site effluent treatment systems with a total score of 5 or more from Table 11 are discretionary activities.

Table 11 – Factors Restricting Choice of Advanced On-Site Effluent Treatment System

Factor 1st Score 2nd Score

(if necessary)

1 Pre-Treatment Level (Maintenance access should be provided)

Advanced treatment unit

1


Below bottom of soakage field land treatment area6 greater than 1200 millimetres between 1000-1200 millimetres between 300-1000 millimetres

between 0-300 millimetres

0 1 2 4

3 Soil Category (Refer to Table 10) 1 gravel, coarse sand; rapid draining; 2 coarse to medium sand; free draining;

3 medium-fine and loamy sand; good drainage; 4 sandy loam, loam and silt loam; moderate drainage; 5 sandy clay-loam, clay-loam and silty clay- loam; moderate to slow drainage. 6 sandy clay, non-swelling clay and silty clay; slow drainage. 7 swelling clay, grey clay, hardpan; poorly

or non-draining.

2 1 1 0 0

2

2

6 See ‘Definition of Terms’ for definition of ‘Treatment Area’


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7 A restrictive soil horizon maybe a change in soil textural class or some other change which severely reduces drainage.

4 Restrictive Soil Horizon7 (barrier to soil soakage)

For irrigation line, i.e. pressure compensating emitters: Restrictive drainage soil horizon within 0.5 metres of soil surface. Restrictive drainage soil horizon deeper than 0.5 metres of soil surface.

2

0

5 Slope

less than 15 percent slope (8.5o) greater than 15% (8.5o)

0 2



greater than 3 metres and greater than 45 degrees

from the toe of a wall/embankment less than 3 metres or less than 45 degrees from the

toe of the wall/embankment

0

4


(i) Greater than or equal to 30 metres (ii) Between 25-30 metres (iii) Between 20-25 metres (iv) Less than 20 metres

0 1 2 4

TOTAL SCORE


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Table 12 – Modification Factors for Advanced On-Site Effluent Treatment Systems The following improvements may be used to modify the treatment or site conditions if the total score from Table 11 exceeds 5.

Limiting Factors Requirement Solution or

Recommendation for Type of Specific Advice

Go Back to Table 11 or apply for discharge permit

1 Pre-treatment Level Improve the pre-treatment level

- Add disinfection - Add nutrient removal

Apply for discharge permit

2 Groundwater too High Improve the clearance to groundwater

- Provide raised bed for effluent land application

- Improve pre-treatment level by adding disinfection

Go Back to Table 11. Apply for discharge permit.

3 Restrictive Soil Horizon - Remove the restriction

- Increase depth to restriction

- Decrease loading - Improve the pre- treatment level

- Break up iron pan/clay pan- Provide raised bed for effluent land application

- Change DIR1 from 5mm/d to 3mm/d

- Change DIR from 5mm/d to 2mm/d

- Add disinfection - Add disinfection and

nutrient removal

Go Back to Table 11. Go Back to Table 11. Apply for discharge permit. Apply for discharge permit. Apply for discharge permit. Apply for discharge permit.

4 Horizontal barrier - Increase distance to barrier

- Improve the pre-

treatment level

- Relocate land application area


nutrient removal

Go back to Table 11 Apply for discharge permit. Apply for discharge permit.

5 Proximity to Surface Water

- Increase distance to surface water

- Improve the pre-treatment level

- Relocate land application area


nutrient removal

Go back to Table 11. Apply for discharge permit. Apply for discharge permit.


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Schedule 3 – Performance Conditions for Existing Systems Installed before the On-Site Effluent Treatment Regional Plan became operative (1 December 1996)

General Authorisation No 9 The discharge of up to 2 m3/day of natural water containing waste from septic tanks or any other domestic sewage system into the ground provided that:

(a) The section area is not less than 1,500 m2 (if subdivided6 after 1 February 1991). (b) Septic tank density does not exceed 1/1,500 m2 within the property boundary where additional

dwellings and accompanying septic tank systems are installed after 1 February 1991. (c) For that area of Waihi Beach previously covered by the Hauraki Catchment Board General

Authorisation Number 14, the section area is to be not less than 1,500 m2 and septic tank density is not to exceed 1/1,500 m2 irrespective of date of subdivision.

(d) The discharge of effluent is not likely to adversely affect land stability, any adjoining landowner or to become detectable in the surrounding water resources (refer notes 1 and 3).

(e) A waste disposal unit (garbage grinder) is not installed unless the effluent system design makes specific allowance for this use (applies to systems installed after 1 February 1991 or existing septic tanks without a grinder) (refer note 3).

(f) Any septic tank installed after 1 February 1991 has a minimum of 600mm depth to water table below the soakage bed at all times or 2,000 mm — if a soak hole is used (refer notes 2 and 3).

(g) The septic tank treatment and disposal system complies with the city/district council requirements. The design and installation is in accordance with NZS Standard Number 4610:1982 (refer note 3).

(h) The septic tank treatment and disposal system is operated and maintained in accordance with NZSI Standard Number 4610:1982 (refer note 3).

(i) The discharge shall not cause or constitute a nuisance as defined in the Health Act (refer note 3).

(j) There is no reticulated sewerage system available (refer note 3). NOTES: 1 Care should be taken to ensure that the treatment system will not cause contamination of any

water supply.

2 In order to meet Condition f of the General Authorisation a raised bed or built up disposal area may be used. Such a system should conform to the principles outline in the Council's guideline for such systems.

3 Conditions d, e, f, g, h, i and j apply to all installations undertaken, irrespective of either section size or when the section was subdivided.

6 Definition of subdivided: subdivision, cross lease or partition


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Schedule 4 – Performance Conditions for Existing Systems Installed after the On-Site Effluent Treatment Regional Plan became operative (1 December 1996) but before the On-Site Effluent Treatment Regional Plan 2006 became Operative

(A) Conventional On-Site Effluent Treatment Systems

6.2.4(a) Rules

6.2.4(a)(i) The discharge of up to 2 cubic metres per day of treated wastewater into land from a conventional on-site effluent treatment system is a permitted activity provided that:

Conditions

(a) Subject to Rule 6.7.4(a)(i) in Schedule 4, for systems existing prior to the plan becoming operative, those systems shall comply with the requirements of Schedule 3, or;

(b) Subject to Rule 6.2.4(a)(i) in Schedule 4, for systems to be installed after the plan became operative (1 December 1996), those systems shall comply with the following:

(i) The site for the system is not subject to slippage, subsidence, erosion or inundation from any source.

(ii) The land application area is located not less than 15 metres from any

drinking water bore and 5 metres from any surface water8. (iii) The requirements set out in Tables 6.1, 6.2 and 6.3 in Schedule 4 (iv) Each system is unable to connect to an existing reticulation system

(for the purposes of this condition, where not otherwise specified in a District Plan, a system is deemed to be unable to connect if the reticulation system is more than 30 metres from the owner’s land or more than 60 metres from the nearest part of the building containing wastewater producing fixtures).

(v) There is no overland flow or surface ponding as a result of the

discharge of the wastewater. (vi) In addition any on-site effluent treatment system located in the

communities specified in 6.7.4(a)(i) in Schedule 4 must also comply with the following:

8 Environment Bay of Plenty will work with Territorial authorities, Regional Authorities and other interested parties to formulate and agree on a consistent set of buffers.


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Each system is subject to a septic tank survey and a regular maintenance programme under which the owner of the system is required to obtain at intervals not greater than three (3) years, a certificate issued by Environment Bay of Plenty following an inspection carried out by a certifier approved by Environment Bay of Plenty certifying that the system meets the conditions set out under Rules 6.2.4(a)(i)(b), 6.3.4(a)(i) and 6.8.4(b)(i) in Schedule 4.

Or each system is subject to a septic tank survey and a regular maintenance programme under which the owner of the system is required to obtain a certificate of compliance at intervals not greater than six (6) years if the:

(vii) Septic tank of the dwelling with no more than three (3) bedrooms has a liquid volume of greater than 2,700 litres, or has a liquid volume greater than 2,000 litres and is fitted with an effluent filter on the outlet of the tank; or

(viii) Septic tank of the dwelling with no more than six (6) bedrooms has a

liquid volume of greater than 3,300 litres, or has a liquid volume greater than 2,500 litres and is fitted with an effluent filter on the outlet of the tank;

The certificate shall be issued by Environment Bay of Plenty following an inspection carried out by a certifier approved by Environment Bay of Plenty, certifying that the system meets the conditions set out under Rules 6.2.4(a)(i)(b), 6.3.4(a)(i) and 6.8.4(b)(i) in Schedule 4.

Or each system is subject to a septic tank survey and a regular

maintenance programme every 3 years administered by the city/district council for the area.

(c) Notwithstanding 6.2.4(a)(i)(b)(ii) in Schedule 4, for systems installed after Plan Change No. 1 becomes operative (6 December 2002), the land application area shall be located not less than 20 metres from any drinking water bore and 20 metres from any surface water.

6.2.4(a)(ii) Nothing in Rule 6.2.4(a)(i) in Schedule 4 shall require conventional on-site effluent treatment systems installed between 1 December 1996 and 19 December 2000 to achieve performance standards in Tables 6.1, 6.2 and 6.3 of Schedule 4 that are more restrictive than that required prior to notification of Change No. 1 to this plan unless:

(a) The system did not comply with this plan at the time the plan change was publicly notified (19 December 2000); or

(b) The system requires upgrading as provided for in Rule 6.8.4(b)(i) in Schedule 4.

6.2.4(a)(iii) Where conventional effluent treatment system fails to comply with Rule 6.2.4(a)(i) in Schedule 4 the discharge shall be a discretionary activity9.

6.2.4(a) (iv) The discharge to soak holes constructed after the date this plan becomes operative is a discretionary activity, requiring an assessment of environmental effects.

9 Details of the criteria Environment Bay of Plenty will use to assess applications for discretionary activity can be found in Appendix F. Where a suitable Treatment Area cannot be found on the Lot (section) a discharge permit may be applied for from Environment Bay of Plenty


107

6.2.4(a)(v) The use of explosives to maintain soakhole infiltration is a prohibited activity.

6.2.4(a)(vi) Discharges from conventional on-site effluent treatment systems shall comply with Rule 6.2.4(a)(i) in Schedule 4 except for urban zoned (residential, commercial, recreational or industrial) areas within the Tauranga City Council boundary in which case the discharges shall be a discretionary activity for systems installed after this plan becomes operative.

6.2.4 Methods of Implementation

6.2.4(a) Rules

6.2.4(a)(i) The discharge of up to 2 cubic metres per day of treated wastewater into land from a conventional on-site effluent treatment system is a permitted activity provided that:

Conditions

(a) Subject to Rule 6.7.4(a)(i), for systems existing prior to the plan becoming operative, those systems shall comply with the requirements of Appendix B, or;

(b) Subject to Rule 6.2.4(a)(i), for systems to be installed after the plan became operative (1 December 1996), those systems shall comply with the following:

(i) The site for the system is not subject to slippage, subsidence, erosion or inundation from any source.

(ii) The land application area is located not less than 15 metres from any

drinking water bore and 5 metres from any surface water9. (iii) The requirements set out in Tables 6.1, 6.2 and 6.3 in Section 6.15. (iv) Each system is unable to connect to an existing reticulation system

(for the purposes of this condition, where not otherwise specified in a District Plan, a system is deemed to be unable to connect if the reticulation system is more than 30 metres from the owner’s land or more than 60 metres from the nearest part of the building containing wastewater producing fixtures).

(v) There is no overland flow or surface ponding as a result of the

discharge of the wastewater. (vi) In addition any on-site effluent treatment system located in the

communities specified in 6.7.4(a)(i) must also comply with the following:

Each system is subject to a septic tank survey and a regular

maintenance programme under which the owner of the system is required to obtain at intervals not greater than three (3) years, a certificate issued by Environment Bay of Plenty following an inspection carried out by a certifier approved by Environment Bay of Plenty certifying that the system meets the conditions set out under Rules 6.2.4(a)(i)(b), 6.3.4(a)(i) and 6.8.4(b)(i).

9 Environment Bay of Plenty will work with Territorial Authorities, Regional Authorities and other interested parties to formulate and agree on a consistent set of buffers.


108


maintenance programme under which the owner of the system is required to obtain a certificate of compliance at intervals not greater than six (6) years if the:

(vii) Septic tank of the dwelling with no more than three (3) bedrooms has a liquid volume of greater than 2,700 litres or has a liquid volume greater than 2,000 litres and is fitted with an effluent filter on the outlet of the tank; or

(viii) Septic tank of the dwelling with no more than six (6) bedrooms has a

liquid volume of greater than 3,300 litres or has a liquid volume greater than 2,500 litres and is fitted with an effluent filter on the outlet of the tank;

The certificate shall be issued by Environment Bay of Plenty following

an inspection carried out by a certifier approved by Environment Bay of Plenty, certifying that the system meets the conditions set out under Rules 6.2.4(a)(i)(b), 6.3.4(a)(i) and 6.8.4(b)(i).


maintenance programme every 3 years administered by the territorial authority for the area.

(c) Notwithstanding 6.2.4(a)(i)(b)(ii), for systems installed after Plan Change No. 1 becomes operative (6 December 2002), the land application area shall be located not less than 20 metres from any drinking water bore and 20 metres from any surface water.

6.2.4(a)(ii) Nothing in Rule 6.2.4(a)(i) shall require conventional on-site effluent treatment systems installed between 1 December 1996 and 19 December 2000 to achieve performance standards in Tables 6.1, 6.2 and 6.3 of Section 6.15 that are more restrictive than that required prior to notification of Change No. 1 to this plan unless:

(a) The system did not comply with this plan at the time the plan change was publicly notified (19 December 2000); or

(b) The system requires upgrading as provided for in Rule 6.8.4(b)(i).


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6.3.4(a) Rules 6.3.4(a)(i) The discharge of treated wastewater into land from an advanced on-site

effluent treatment system is a permitted activity provided that: Conditions (a) The maximum discharge does not exceed 2 cubic metres per day; (b) The site for the system is not subject to slippage, subsidence, erosion

or inundation from any source;

(c) The land application area is located not less than 20 metres from any drinking water bore and 20 metres from any surface water9;

(d) Each system is unable to connect to an existing reticulation system (for the purposes of this condition, where otherwise not specified in a district plan, a system is deemed to be unable to connect if the reticulation system is more than 30 metres from the owner’s land or more than 60 metres from the nearest part of the building containing wastewater producing fixtures).

(e) The system complies with the requirements set out in Table 6.2 in Section 6.15;

(f) The wastewater flow receives advanced treatment such that the effluent quality shall not be less than a secondary treatment standard of 30 grams per cubic metres of BOD5 and 45 grams per cubic metres of suspended solids prior to discharge to the dispersal system;

(g) Secondary treated wastewater shall be applied by sub-surface irrigation at a rate not exceeding 5 litres per square metres per day;

(h) Irrigation lines emitters used for the dispersal of treated wastewater shall be installed either: (i) beneath the surface of the soil between 100 millimetres –

200 millimetres; or (ii) on the surface of the soil and covered by an inert material (e.g.

bark), or an appropriate alternative, to a minimum depth of 100 millimetres;

(i) Subject to condition (g) above, the horizontal separation distance between irrigation lines emitters shall be set to ensure that an even distribution of treated wastewater to the ground occurs;

(j) There is no overland flow or surface ponding as a result of the discharge of the wastewater;

(k) There is no land application by surface irrigation or any method which may produce any aerosol discharge into air;

(l) Subject to condition (f) above, the pre-treatment and dispersal system shall be operated and maintained in accordance with the manufacturer’s design specification for effluent quality including regular desludging;

(m) A written record of all servicing and maintenance carried out on the wastewater treatment system shall be kept and a copy of this record shall be forwarded to Environment Bay of Plenty within 90 days of a service or maintenance check required by condition (l) above;

9 Environment Bay of Plenty will work with Territorial Authorities, Regional Authorities and other interested parties to formulate and agree on a consistent set of buffers.


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(n) A certificate of performance shall be lodged by the manufacturer with Environment Bay of Plenty. The certificate shall include the following information: (i) Test/trial results demonstrating that the type of pre-treatment

unit, if correctly installed and maintained, will meet the conditions set out in this rule;

(ii) The minimum maintenance requirements for the system; (iii) Whether the pre-treatment unit design makes specific allowance

for a waste disposal unit (garbage grinder); and (o) Certification is also required by Environment Bay of Plenty from the

installer that the system has been installed to the manufacturer’s specifications.


6.7.4(a) Rule

6.7.4(a)(i) Discharges into land from conventional on-site effluent treatment systems located in urban zoned (residential, commercial, recreational, industrial, lake (lakeside settlement), rural residential or future urban) areas of the communities of Maketu, Little Waihi Reclamation Area, Waihi Beach, Omokoroa, Tarawera, Okareka, Tanners Point, Athenree, Woodlands, Gisborne Point, Hamurana, Hinehopu, Okawa Bay and Mourea and in existence prior to the plan becoming operative shall be a discretionary activity three years after the date this plan became operative (1 December 1996) unless within that time:

(a) Each system is subject to septic tank survey and a regular maintenance programme under which the owner of the system is required to obtain at intervals not greater than three (3) years, a certificate issued by Environment Bay of Plenty following an inspection carried out by a certifier approved by Environment Bay of Plenty certifying that the system meets the conditions set out under Rules 6.2.4(a)(i)(b), 6.3.4(a)(i) and 6.8.4(b)(i).

(b) Or each system is subject to a septic tank survey and a regular maintenance

programme under which the owner of the system is required to obtain a certificate of compliance at intervals not greater than (6) six years if the:

(i) septic tank of the dwelling with no more than three (3) bedrooms has a

liquid volume of greater than 2,700 litres or has a liquid volume greater than 2,000 litres and is fitted with an effluent filter on the outlet of the tank; or

(ii) septic tank of the dwelling with no more than six (6) bedrooms has a liquid volume of greater than 3,300 litres or has a liquid volume greater than 2,500 litres and is fitted with an effluent filter on the outlet of the tank;

(c) The certificate shall be issued by Environment Bay of Plenty following an inspection carried out by a certifier approved by Environment Bay of Plenty certifying that the system meets the conditions set out under Rules 6.2.4(a)(i)(b), 6.3.4(a)(i) and 6.8.4(b)(i).


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Or each system is subject to a septic tank survey and regular maintenance

programme every 3 years administered by the territorial authority for the area.

In which case they shall be permitted activities.

(d) A “Septic Tank Survey” is defined as “a survey where all properties containing septic tanks are visited, the tank contents are pumped out, the

capacity and structural integrity of the tank is assessed and an assessment is made of the capacity and operational performance of the soakage field or soakhole”.

Note: Please note that for any advanced on-site effluent treatment systems outlined in section 6.3, Rule 6.3.4(a)(i)(m) requires that a written record of all servicing and maintenance carried out on the wastewater treatment system shall be kept and a copy of this record shall be forwarded to Environment Bay of Plenty within 90 days of a service or maintenance check required by condition 6.3.4(a)(i)(l).

6.8.4(b) Rule

6.8.4(b)(i) Where an on-site effluent treatment system fails, the system shall be upgraded, or replaced with a new system that complies with either Rule 6.2.4(a)(i)(b) or Rule 6.3.4(a)(i).

Table 6.1: Septic Tank Capacities

A: Number of Bedrooms Minimum Tank Capacity/Size (Litres)* 1 to 3 2,700 4 to 6 3,300 7 or more Probably exceeds 2 cubic metres per day and therefore is discretionary. Note: *As volume measured from outlet invert to septic tank base (i.e. liquid volume). If a garbage grinder is installed in a conventional effluent system, then: Effluent outlet filter should be installed at the outlet of the septic tank to protect the soakage field, or the tank size is increased to the larger size to accommodate the extra solids produced.

B: Households (Blocks of Units/Flats) (Refer to Table 6.5) For 10 persons or more the capacity (C) may be determined by the formula C = (P x A) + 2,000 litres where P = the number of persons to be served and A = the daily wastewater flow allowance in litres/person/day


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C: Institutions (Refer to Table 6.5) For flows greater than 700 litres per day the capacity (C) may be determined by the formulae

as set out below: Motels/Hotels - without restaurant C = (P x A) + 2,000 litres - with restaurant C = (P x A) + 3,000 litres Community halls, schools, rural C = (P x A) + 2,000 litres factories, shopping centres, camping grounds where P = the number of persons to be served and A = the daily wastewater flow allowance in litres per person per day


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Table 6.2: Factors restricting choice of system Select one item from each of numbered sections below and put the score in “1st score” column to find out first score.

On-site effluent treatment systems with a total score between 1 and 3 (inclusive) from Table 6.2 are permitted activities provided they meet the requirements of Rules 6.2.4(a)(i) and 6.3.4 (a)(i). On-site effluent treatment systems with a score of 4 or more from Table 6.2 are discretionary activities unless the systems can be modified in accordance with the modification factors set out in Table 6.4.

Factor 1st Score

2nd Score (if

necessary) 1 Pre-Treatment Level (Maintenance access should be provided)

(a) Single stage septic tank (b) Two stage septic tank or single stage septic tank and approved effluent outlet filter (c) Two stage septic tank and approved

effluent outlet filter (d) Greywater only (e) Advanced treatment unit

3 2 2 1 1


(a) Conventional On-Site Effluent Systems below bottom of soakage field land treatment area (refer to definition of treatment area in Appendix M) greater than 600 millimetres less than 600 millimetres

(b) Advanced On-Site Effluent Systems Below bottom of the irrigation lines e.g. pressure compensating emitters for treatment level 1(e) above greater than 300 millimetres less than 300 millimetres

0 4 0 4

3 Soil Category (Refer to Table 6)

1 gravel, coarse sand; rapid draining; 2 coarse to medium sand; free draining; 3 medium-fine and loamy sand; good

drainage; 4 sandy loam, loam and silt loam; moderate

drainage; 5 sandy clay-loam, clay-loam and silty clay-

loam; moderate to slow drainage.

1 0 0 0 0

*A restrictive soil horizon maybe a change in soil textural class or some other change which severely reduces drainage.


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4 Restrictive Soil Horizon* (barrier to soil soakage)

Restrictive drainage soil horizon* within 2 metres of soil surface.

Restrictive drainage soil horizon deeper than 2 metres of soil surface.

For irrigation lines e.g. pressure compensating emitters:

Restrictive drainage soil horizon within 0.5

metres of soil surface. Restrictive drainage soil horizon deeper than 0.5

metres of soil surface.

3

0

2

0

5 Slope less than15 percent slope (8.5o) greater than 15% (8.5o)

0 2



No Yes For irrigation lines e.g. pressure compensating

emitters. No Yes

0 3

0 2


(a) For systems installed after 1 December 1996

to the date Plan Change No 1 becomes operative:

(i) Greater than or equal to 20 metres (ii) Greater than or equal to 5 metres, but

less than 20 metres (iii) less than 5 metres

(b) For systems installed after Plan Change No

1 becomes operative (6 December 2002):

(i) Greater or equal to 20 metres (ii) Less than 20 metres

0

1 4

0 4

TOTAL SCORE


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Table 6.3: Effluent treatment trench length required (in metres) for

discharge volumes of up to 2 cubic metres per day to standard trenches

Soil Category

1 (**LPED) 2 3 4 5

Ave

rage

dai

ly

flow

(L)

Num

ber

of

Bed

room

s

Min

. Tre

nch

Leng

th (m

etre

s)

Req

.

Are

a R

eq.

(met

res2 ) i

ncl.

Res

erve

Are

a

Min

. Tre

nch

Leng

th (m

etre

s)

Req

. A

rea

Req

. (m

etre

s2 ) inc

l. R

eser

ve A

rea

Min

. Tre

nch

Leng

th (m

etre

s)

Req

. A

rea

Req

. (m

etre

s2 ) inc

l. R

eser

ve A

rea

Min

. Tre

nch

Leng

th (m

etre

s)

Req

. A

rea

Req

. (m

etre

s2 ) inc

l. R

eser

ve A

rea

Min

. Tre

nch

Leng

th (m

etre

s)

Req

. A

rea

Req

. (m

etre

s2 ) inc

l. R

eser

ve A

rea

Up to 500* 16 64 22 90 37 150 45 180 75 300

Up to 1000 1 to 3 32 128 45 180 74 300 90 360 150 600

1000-1400 4 45 180 60 240 105 420 125 500 210 840

1400-1600 5 50 200 70 280 120 480 145 580 240 960

1600-2000 6 64 256 90 360 148 590 180 720 300 1200

More than 2000

7 or more Expected to exceed 2 cubic metres per day

* This applies to non-habitable dwellings that is not inhabited by humans and includes a building

that is not used for temporary accommodation such as offices or service stations for example. ** For all category 1 soils a low pressure effluent distribution system (LPED) must be used. This

system utilises pump dosed loading from a perforated small diameter pipe inserted within trenches (refer to Figure 6.2). Designed for use in free draining standard distribution lines in standard trenches (refer to Figure 6.1) or in shallow and narrow soils (category 1 - gravel, coarse sand; rapid draining) it is essentially a variation on conventional distributions systems.

Soil Category 1 = gravel, coarse sand; rapid draining; Soil Category 2 = coarse to medium sand; free draining; Soil Category 3 = medium-fine and loamy sand; good drainage; Soil Category 4 = sandy loam, loam and silt loam; moderate drainage; Soil Category 5 = sandy clay-loam, clay-loam and silty clay-loam; moderate to slow drainage.

If an LPED or pump system is used, an alarm/warning system is required to detect failure of the system at an early stage.

Table 6.3 is based on the following: • 0.45 metre wide gravel filled standard trench (Figure 6.1 trench configuration). The width

of the trench may be reduced (Figure 6.2 trench configuration) as long as the trench length from Table 6.3 is increased by the following formula:

Narrow Trench Length = (T x 0.45)÷W

where T = trench length from Table 6.3 W = trench width. The trench width must not exceed 0.45 metres.

D = spacing between adjacent trenches (sidewall to sidewall). The minimum is 1 metre although 2 metres is preferable (see diagram below).


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• 100% reserve area so that if the soakage field fails, there is room to develop another field.

• For discretionary activities these lengths may exceed those recommended in Table 6.3.

• Any compaction of a soakage field is to be avoided.

1 metre

Ground surface


117


118


119

B Performance Conditions (see Rule 6.2.4(a)(i))

General Authorisation No 9

The discharge of up to 2 m3/day of natural water containing waste from septic tanks or any other domestic sewage system into the ground provided that:

(a) The section area is not less than 1,500 m2 (if subdivided8 after 1 February 1991).

(b) Septic tank density does not exceed 1/1,500 m2 within the property boundary where additional dwellings and accompanying septic tank systems are installed after 1 February 1991.

(c) For that area of Waihi Beach previously covered by the Hauraki Catchment Board General Authorisation Number 14, the section area is to be not less than 1,500 m2 and septic tank density is not to exceed 1/1,500 m2 irrespective of date of subdivision.

(d) The discharge of effluent is not likely to adversely affect land stability, any adjoining landowner or to become detectable in the surrounding water resources (refer notes 1 and 3).

(e) A waste disposal unit (garbage grinder) is not installed unless the effluent system design makes specific allowance for this use (applies to systems installed after 1 February 1991 or existing septic tanks without a grinder) (refer note 3).

(f) Any septic tank installed after 1 February 1991 has a minimum of 600 mm depth to water table below the soakage bed at all times or 2,000 mm — if a soak hole is used (refer notes 2 and 3).

(g) The septic tank treatment and disposal system complies with the Territorial Local Authority requirements. The design and installation is in accordance with NZS Standard Number 4610:1982 (refer note 3).

(h) The septic tank treatment and disposal system is operated and maintained in accordance with NZSI Standard Number 4610:1982 (refer note 3).

(i) The discharge shall not cause or constitute a nuisance as defined in the Health Act (refer note 3).

(j) There is no reticulated sewerage system available (refer note 3).

NOTES:

1 Care should be taken to ensure that the treatment system will not cause contamination of any water supply.

2 In order to meet Condition f of the General Authorisation a raised bed or built up disposal area may be used. Such a system should conform to the principles outline in the Council's guideline for such systems.

3 Conditions d, e, f, g, h, i and j apply to all installations undertaken, irrespective of either section size or when the section was subdivided.

108 Definition of subdivided: subdivision, cross lease or partition.


121

Schedule 5 Maps of Rotorua Lakes Catchments

Map 4 Rotorua Lakes Catchments

Map 5 Lakes Rotoehu and Rotoma

Map 6 Lakes Rotoiti and Rotokawau

Map 7 Lakes Okataina & Okareka

Map 8 Lakes Tarawera, Tikitapu and Rotokakahi

Map 9 Lakes Rotomahana, Rerewhakaaitu and Okaro

Map 10 Lake Rotorua


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Map 4 – Rotorua Lakes Catchment


125

Map 5 – Lakes Rotoehu and Rotoma


127

Map 6 – Lakes Rotoiti and Rotokawau


129

Map 7 – Lakes Okataina and Okareka


131

Map 8 – Lakes Tarawera, Tikitapu and Rotokakahi


133

Map 9 – Lakes Rotomahana, Rerewhakaaitu and Okaro


135

Map 10 – Lake Rotorua


137

Schedule 6 Maintenance Zone Maps

Map 11 (Sheet 1 of 2) Hamurana

Map 11 (Sheet 2 of 2) Hamurana

Map 12 (Sheet 1 of 4) Brunswick/Rotokawa




Map 13 (Sheet 1 of 2) Okawa Bay/Mourea

Map 13 (Sheet 2 of 2) Okawa Bay/Mourea

Map 14 (Sheet 1 of 2) Okere Falls

Map 14 (Sheet 2 of 2) Okere Falls

Map 15 (Sheet 1 of 2) Otaramarae

Map 15 (Sheet 2 of 2) Otaramarae

Map 16 (Sheet 1 of 1) Gisborne Point

Map 17 (Sheet 1 of 1) Hinehopu

Map 18 (Sheet 1 of 2) Lake Rotoma

Map 18 (Sheet 2 of 2) Lake Rotoma

Map 19 (Sheet 1 of 1) Lake Okareka

Map 20 (Sheet 1 of 3) Lake Tarawera



Map 21 (Sheet 1 of 1) Tanners Point

Map 22 (Sheet 1 of 1) Ongare Point

Map 23 (Sheet 1 of 3) Omokoroa



Map 24 (Sheet 1 of 1) Te Puna

Map 25 (Sheet 1 of 1) Maketu

Map 26 (Sheet 1 of 1) Little Waihi


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